Home/Federal/Federal Register/2021-25414

Proposed Rule2021-25414

Energy Conservation Program: Test Procedure for Circulator Pumps

Primary source

Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.

Published

December 20, 2021

Issuing agencies

Energy Department

Abstract

The U.S. Department of Energy ("DOE") proposes to establish definitions, a test procedure, sampling and rating requirements, and enforcement provisions for circulator pumps. Currently, circulator pumps are not subject to DOE test procedures or energy conservation standards. DOE proposes a test procedure for measuring the circulator energy index for circulator pumps. The proposed test method references the relevant industry test standard. The proposed definitions and test procedures are based on the recommendations of the Circulator Pump Working Group, which was established under the Appliance Standards Rulemaking Federal Advisory Committee. DOE is seeking comment from interested parties on the proposal.

Full Text

<html>
<head>
<title>Federal Register, Volume 86 Issue 241 (Monday, December 20, 2021)</title>
</head>
<body><pre>
[Federal Register Volume 86, Number 241 (Monday, December 20, 2021)]
[Proposed Rules]
[Pages 72096-72144]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-25414]

[[Page 72095]]

Vol. 86

Monday,

No. 241

December 20, 2021

Part IV

Department of Energy

-----------------------------------------------------------------------

10 CFR Parts 429 and 431

Energy Conservation Program: Test Procedure for Circulator Pumps;
Proposed Rule

Federal Register / Vol. 86 , No. 241 / Monday, December 20, 2021 /
Proposed Rules

[[Page 72096]]

-----------------------------------------------------------------------

DEPARTMENT OF ENERGY

10 CFR Parts 429 and 431

[EERE-2016-BT-TP-0033]
RIN 1904-AD77

Energy Conservation Program: Test Procedure for Circulator Pumps

AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.

ACTION: Notice of proposed rulemaking and request for comment.

-----------------------------------------------------------------------

SUMMARY: The U.S. Department of Energy (``DOE'') proposes to establish
definitions, a test procedure, sampling and rating requirements, and
enforcement provisions for circulator pumps. Currently, circulator
pumps are not subject to DOE test procedures or energy conservation
standards. DOE proposes a test procedure for measuring the circulator
energy index for circulator pumps. The proposed test method references
the relevant industry test standard. The proposed definitions and test
procedures are based on the recommendations of the Circulator Pump
Working Group, which was established under the Appliance Standards
Rulemaking Federal Advisory Committee. DOE is seeking comment from
interested parties on the proposal.

DATES: DOE will accept comments, data, and information regarding this
proposal no later than February 18, 2022. See section V ``Public
Participation,'' for details. DOE will hold a webinar on Wednesday,
February 2, 2022, from 12:30 p.m. to 3:30 p.m. See section V, ``Public
Participation,'' for webinar registration information, participant
instructions, and information about the capabilities available to
webinar participants. If no participants register for the webinar, it
will be cancelled.

ADDRESSES: Interested persons are encouraged to submit comments using
the Federal eRulemaking Portal at <a href="http://www.regulations.gov">www.regulations.gov</a>. Follow the
instructions for submitting comments. Alternatively, interested persons
may submit comments, identified by docket number EERE-2016-BT-TP-0033,
by any of the following methods:
1. Federal eRulemaking Portal: <a href="http://www.regulations.gov">www.regulations.gov</a>. Follow the
instructions for submitting comments.
2. Email: to <a href="/cdn-cgi/l/email-protection#46052f3425332a2732293416332b3635747677701216767675750623236822292368212930">[email&#160;protected]</a>. Include docket
number EERE-2016-BT-TP-0033 in the subject line of the message.
No telefacsimiles (``faxes'') will be accepted. For detailed
instructions on submitting comments and additional information on this
process, see section V of this document.
Although DOE has routinely accepted public comment submissions
through a variety of mechanisms, including the Federal eRulemaking
Portal, email, postal mail, or hand delivery/courier, the Department
has found it necessary to make temporary modifications to the comment
submission process in light of the ongoing coronavirus 2019 (``COVID-
19'') pandemic. DOE is currently suspending receipt of public comments
via postal mail and hand delivery/courier. If a commenter finds that
this change poses an undue hardship, please contact Appliance Standards
Program staff at (202) 586-1445 to discuss the need for alternative
arrangements. Once the COVID-19 pandemic health emergency is resolved,
DOE anticipates resuming all of its regular options for public comment
submission, including postal mail and hand delivery/courier.
Docket: The docket, which includes Federal Register notices, public
meeting attendee lists and transcripts (if a public meeting is held),
comments, and other supporting documents/materials, is available for
review at <a href="http://www.regulations.gov">www.regulations.gov</a>. All documents in the docket are listed
in the <a href="http://www.regulations.gov">www.regulations.gov</a> index. However, some documents listed in the
index, such as those containing information that is exempt from public
disclosure, may not be publicly available.
The docket web page can be found at <a href="http://www.regulations.gov/docket/EERE-2016-BT-STD-0004">www.regulations.gov/docket/EERE-2016-BT-STD-0004</a>. The docket web page contains instructions on how
to access all documents, including public comments, in the docket. See
section V for information on how to submit comments through
<a href="http://www.regulations.gov">www.regulations.gov</a>.

FOR FURTHER INFORMATION CONTACT:
Mr. Jeremy Dommu, U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy, Building Technologies Office, EE-2J,
1000 Independence Avenue SW, Washington, DC, 20585-0121. Telephone:
(202) 586-9870. Email: <a href="/cdn-cgi/l/email-protection#59182929353038373a3c0a2d38373d382b3d2a082c3c2a2d3036372a193c3c773d363c773e362f">[email&#160;protected]</a>.
Ms. Amelia Whiting, U.S. Department of Energy, Office of the
General Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC,
20585-0121. Telephone: 202-586-2588. Email: <a href="/cdn-cgi/l/email-protection#e5a48880898c84cbb28d8c918c8b82a58d94cb818a80cb828a93">[email&#160;protected]</a>.
For further information on how to submit a comment, review other
public comments and the docket, or participate in the public meeting,
contact the Appliance and Equipment Standards Program staff at (202)
287-1445 or by email: <a href="/cdn-cgi/l/email-protection#f0b180809c99919e9395a384919e9491829483a185958384999f9e83b09595de949f95de979f86">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION: DOE proposes to incorporate by reference the
following industry standard into part 431:
Hydraulic Institute (``HI'') 40.6-2021, (``HI 40.6-2021'')
``Methods for Rotodynamic Pump Efficiency Testing''.
Copies of HI 40.6-2021 can be obtained from: the Hydraulic
Institute at 6 Campus Drive, First Floor North, Parsippany, NJ 07054-
4406, (973) 267-9700, or by visiting: <a href="http://www.Pumps.org">www.Pumps.org</a>.
For a further discussion of this standard, see section IV.M. of
this document.

Table of Contents

I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Notice of Proposed Rulemaking
III. Discussion
A. General Comments
B. Scope and Definitions
1. CPWG Recommendations
2. Definition of Circulator Pump
3. Definition of Circulator Pump Varieties
4. Definition of Circulator-Less-Volute and Header Pump
5. Definition of On-Demand Circulator Pumps
6. Applicability of Test Procedure Based on Pump Configuration
7. Basic Model
C. Rating Metric
D. Test Methods for Different Circulator Pump Categories and
Control Varieties
1. Definitions Related to Circulator Pump Control Varieties
2. Reference System Curve
3. Pressure Control
4. Temperature Control
5. Manual Speed Control
6. External Input Signal Control
7. No Controls
E. Determination of Circulator Pump Performance
1. Incorporation by Reference of HI 40.6-2021
2. Exceptions, Modifications and Additions to HI 40.6-2021
a. Applicability and Clarification of Certain Sections of HI
40.6-2021
b. Testing Twin Head Circulator Pumps and Circulators-Less-
Volute
c. Determination of Circulator Pump Driver Power Input at
Specified Flow Rates
d. Calculation and Rounding Modifications and Additions
3. Rated Hydraulic Horsepower
F. Sampling Plan and Enforcement Provisions for Circulator Pumps
1. Sampling Plan
2. Enforcement Provisions
G. Representations of Energy Use and Energy Efficiency
H. Test Procedure Costs and Harmonization
1. Test Procedure Costs and Impact
a. Estimated Capital Costs for Testing Circulator Pumps

[[Page 72097]]

b. Between Estimated Labor Costs for Testing Circulator Pumps
2. Harmonization With Industry Standards
I. Compliance Date
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility Act
1. Description of Why Action Is Being Considered
2. Objective of, and Legal Basis for, Rule
3. Description and Estimate of Small Entities Regulated
4. Description and Estimate of Compliance Requirements
5. Duplication Overlap, and Conflict With Other Rules and
Regulations
6. Significant Alternatives to the Rule
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
M. Materials Incorporated by Reference
V. Public Participation
A. Participation in the Webinar
B. Procedure for Submitting Prepared General Statements for
Distribution
C. Conduct of the Webinar
D. Submission of Comments
E. Issues on Which DOE Seeks Comment

I. Authority and Background

Pumps are included in the list of ``covered equipment'' for which
DOE is authorized to establish test procedures and energy conservation
standards. (42 U.S.C. 6311(1)(A)) Circulator pumps, which are the
subject of this notice of proposed rulemaking (``NOPR''), are a
category of pumps. Circulator pumps generally are designed to circulate
water in commercial and residential applications. Circulator pumps do
not include dedicated-purpose pool pumps, for which test procedures and
energy conservation standards are established in title 10 of the Code
of Federal Regulations (``CFR'') part 431 subpart Y. Currently,
circulator pumps are not subject to DOE test procedures or energy
conservation standards. The following sections discuss DOE's authority
to establish test procedures for circulator pumps and relevant
background information regarding DOE's consideration of test procedures
for this equipment.

A. Authority

The Energy Policy and Conservation Act, as amended (``EPCA''),\1\
authorizes DOE to regulate the energy efficiency of a number of
consumer products and certain industrial equipment. (42 U.S.C. 6291-
6317) Title III, Part C \2\ of EPCA, added by Public Law 95-619, Title
IV, section 441(a) (42 U.S.C. 6311-6317 as codified), established the
Energy Conservation Program for Certain Industrial Equipment, which
sets forth a variety of provisions designed to improve energy
efficiency. This equipment includes pumps, the subject of this
document. (42 U.S.C. 6311(1)(A))
---------------------------------------------------------------------------

\1\ All references to EPCA in this document refer to the statute
as amended through the Energy Act of 2020, Public Law 116-260 (Dec.
27, 2020).
\2\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------

The energy conservation program under EPCA consists essentially of
four parts: (1) Testing, (2) labeling, (3) Federal energy conservation
standards, and (4) certification and enforcement procedures. Relevant
provisions of EPCA include definitions (42 U.S.C. 6311), test
procedures (42 U.S.C. 6314), labeling provisions (42 U.S.C. 6315),
energy conservation standards (42 U.S.C. 6313), and the authority to
require information and reports from manufacturers (42 U.S.C. 6316).
The Federal testing requirements consist of test procedures that
manufacturers of covered equipment must use as the basis for: (1)
Certifying to DOE that their equipment complies with the applicable
energy conservation standards adopted pursuant to EPCA (42 U.S.C.
6316(a); 42 U.S.C. 6295(s)), and (2) making representations about the
efficiency of that equipment (42 U.S.C. 6314(d)). Similarly, DOE must
use these test procedures to determine whether the equipment complies
with relevant standards promulgated under EPCA. (42 U.S.C. 6316(a); 42
U.S.C. 6295(s))
Federal energy efficiency requirements for covered equipment
established under EPCA generally supersede State laws and regulations
concerning energy conservation testing, labeling, and standards. (42
U.S.C. 6316(a) and 42 U.S.C. 6316(b); 42 U.S.C. 6297) DOE may, however,
grant waivers of Federal preemption for particular State laws or
regulations, in accordance with the procedures and other provisions of
EPCA. (42 U.S.C. 6316(b)(2)(D))
Under 42 U.S.C. 6314, EPCA sets forth the criteria and procedures
DOE must follow when prescribing or amending test procedures for
covered equipment. EPCA requires that any test procedures prescribed or
amended under this section must be reasonably designed to produce test
results which reflect energy efficiency, energy use or estimated annual
operating cost of a given type of covered equipment during a
representative average use cycle and requires that test procedures not
be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2))
Before prescribing any final test procedures, the Secretary must
publish proposed test procedures in the Federal Register and afford
interested persons an opportunity (of not less than 45 days' duration)
to present oral and written data, views, and arguments on the proposed
test procedures. (42 U.S.C. 6314(b))
DOE is publishing this NOPR in accordance with the statutory
authority in EPCA.

B. Background

As stated, EPCA includes ``pumps'' among the industrial equipment
listed as ``covered equipment'' for the purpose of Part A-1, although
EPCA does not define the term ``pump.'' (42 U.S.C. 6311(1)(A)) In a
final rule published January 25, 2016, DOE established a definition for
``pump,'' associated definitions, and test procedures for certain
pumps. 81 FR 4086 (``January 2016 TP final rule''). ``Pump'' is defined
as equipment designed to move liquids (which may include entrained
gases, free solids, and totally dissolved solids) by physical or
mechanical action and includes a bare pump and, if included by the
manufacturer at the time of sale, mechanical equipment, driver, and
controls. 10 CFR 431.462. Circulator pumps fall within the scope of
this definition.
While DOE has defined ``pump'' broadly, the test procedure
established in the January 2016 TP final rule is applicable only to
certain categories of clean water pumps,\3\ specifically those that are
end suction close-coupled; end suction frame mounted/own bearings; in-
line (``IL''); radially split, multi-stage, vertical, in-line diffuser
casing; and submersible turbine (``ST'') pumps with the following
characteristics:
---------------------------------------------------------------------------

\3\ A ``clean water pump'' is a pump that is designed for use in
pumping water with a maximum non-absorbent free solid content of
0.016 pounds per cubic foot, and with a maximum dissolved solid
content of 3.1 pounds per cubic foot, provided that the total gas
content of the water does not exceed the saturation volume, and
disregarding any additives necessary to prevent the water from
freezing at a minimum of 14 [deg]F. 10 CFR 431.462.
---------------------------------------------------------------------------

<bullet> 25 gallons per minute (``gpm'') and greater (at best
efficiency point (``BEP'') at full impeller diameter);

[[Page 72098]]

<bullet> 459 feet of head maximum (at BEP at full impeller diameter
and the number of stages specified for testing);
<bullet> design temperature range from 14 to 248 [deg]F;
<bullet> designed to operate with either (1) a 2- or 4-pole
induction motor, or (2) a non-induction motor with a speed of rotation
operating range that includes speeds of rotation between 2,880 and
4,320 revolutions per minute (``rpm'') and/or 1,440 and 2,160 rpm, and
in either case, the driver and impeller must rotate at the same speed;
<bullet> 6-inch or smaller bowl diameter for ST pumps;
<bullet> A specific speed less than or equal to 5,000 for ESCC and
ESFM pumps;
<bullet> Except for: Fire pumps, self-priming pumps, prime-assist
pumps, magnet driven pumps, pumps designed to be used in a nuclear
facility subject to 10 CFR part 50, ``Domestic Licensing of Production
and Utilization Facilities''; and pumps meeting the design and
construction requirements set forth in any relevant military
specifications. \4\
---------------------------------------------------------------------------

\4\ E.g., MIL-P-17639F, ``Pumps, Centrifugal, Miscellaneous
Service, Naval Shipboard Use'' (as amended); MIL-P-17881D, ``Pumps,
Centrifugal, Boiler Feed, (Multi-Stage)'' (as amended); MIL-P-
17840C, ``Pumps, Centrifugal, Close-Coupled, Navy Standard (For
Surface Ship Application)'' (as amended); MIL-P-18682D, ``Pump,
Centrifugal, Main Condenser Circulating, Naval Shipboard'' (as
amended); and MIL-P-18472G, ``Pumps, Centrifugal, Condensate, Feed
Booster, Waste Heat Boiler, And Distilling Plant'' (as amended).
Military specifications and standards are available at <a href="http://everyspec.com/MIL-SPECS">http://everyspec.com/MIL-SPECS</a>.

10 CFR 431.464(a)(1). The pump categories subject to the current test
procedures are referred to as ``general pumps'' in this document. As
stated, circulator pumps are not general pumps.
DOE also published a final rule establishing energy conservation
standards applicable to certain classes of general pumps. 81 FR 4368
(Jan. 26, 2016) (``January 2016 ECS final rule''); see also, 10 CFR
431.465.
The January 2016 TP final rule and the January 2016 ECS final rule
implemented the recommendations of the Commercial and Industrial Pump
Working Group (``CIPWG'') established through the Appliance Standards
Rulemaking Federal Advisory Committee (``ASRAC'') to negotiate
standards and a test procedure for general pumps. (Docket No. EERE-
2013-BT-NOC-0039) The CIPWG approved a term sheet containing
recommendations to DOE on appropriate standard levels for general
pumps, as well as recommendations addressing issues related to the
metric and test procedure for general pumps (``CIPWG
recommendations''). (Docket No. EERE-2013-BT-NOC-0039, No. 92)
Subsequently, ASRAC approved the CIPWG recommendations. The CIPWG
recommendations included initiation of a separate rulemaking for
circulator pumps. (Docket No. EERE-2013-BT-NOC-0039, No. 92,
Recommendation #5A at p. 2)
On February 3, 2016, DOE issued a notice of intent to establish the
circulator pumps working group to negotiate a notice of proposed
rulemaking (``NOPR'') for energy conservation standards for circulator
pumps to negotiate, if possible, Federal standards and a test procedure
for circulator pumps and to announce the first public meeting. 81 FR
5658. The members of the Circulator Pump Working Group (``CPWG'') were
selected to ensure a broad and balanced array of interested parties and
expertise, including representatives from efficiency advocacy
organizations and manufacturers. Additionally, one member from ASRAC
and one DOE representative were part of the CPWG. Table I.1 lists the
15 members of the CPWG and their affiliations.

Table I.1--ASRAC Circulator Pump Working Group Members and Affiliations
------------------------------------------------------------------------
Member Affiliation
------------------------------------------------------------------------
Charles White........................... Plumbing-Heating-Cooling
Contractors Association.
Gabor Lechner........................... Armstrong Pumps, Inc.
Gary Fernstrom.......................... California Investor-Owned
Utilities.
Joanna Mauer............................ Appliance Standards Awareness
Project.
Joe Hagerman............................ U.S. Department of Energy.
Laura Petrillo-Groh..................... Air-Conditioning, Heating, and
Refrigeration Institute.
Lauren Urbanek.......................... Natural Resources Defense
Council.
Mark Chaffee............................ TACO, Inc.
Mark Handzel............................ Xylem Inc.
Peter Gaydon............................ Hydraulic Institute.
Richard Gussert......................... Grundfos Americas Corporation.
David Bortolon.......................... Wilo Inc.
Russell Pate............................ Rheem Manufacturing Company.
Don Lanser.............................. Nidec Motor Corporation.
Tom Eckman.............................. Northwest Power and
Conservation Council (ASRAC
member).
------------------------------------------------------------------------

The CPWG commenced negotiations at an open meeting on March 29,
2016, and held six additional meetings to discuss scope, metrics, and
the test procedure. The CPWG concluded its negotiations for test
procedure topics on September 7, 2016, with a consensus vote to approve
a term sheet containing recommendations to DOE on scope, definitions,
metric, and the basis of the test procedure (``September 2016 CPWG
Recommendations''). The September 2016 CPWG Recommendations are
available in the CPWG docket. (Docket No. EERE-2016-BT-STD-0004, No.
58)
The CPWG continued to meet to address potential energy conservation
standards for circulator pumps. Those meetings began on November 3-4,
2016 and concluded on November 30, 2016, with approval of a second term
sheet (``November 2016 CPWG Recommendations'') containing CPWG
recommendations related to energy conservation standards, applicable
test procedure, labeling and certification requirements for circulator
pumps. (Docket No. EERE-2016-BT-STD-0004, No. 98) ASRAC subsequently
voted unanimously to approve the September and November 2016 CPWG
Recommendations during a December meeting. (Docket No. EERE-2013-BT-
NOC-0005, No. 91 at p. 2) \5\
---------------------------------------------------------------------------

\5\ All references in this document to the approved
recommendations included in 2016 Term Sheets are noted with the
recommendation number and a citation to the appropriate document in
the CPWG docket (e.g., Docket No. EERE-2016-BT-STD-0004, No. #,
Recommendation #X at p. Y). References to discussions or suggestions
of the CPWG not found in the 2016 Term Sheets include a citation to
meeting transcripts and the commenter, if applicable (e.g., Docket
No. EERE-2016-BT-STD-0004, [Organization], No. X at p. Y).
---------------------------------------------------------------------------

In a letter dated June 9, 2017, Hydraulic Institute (``HI'')
expressed its support for the process that DOE initiated regarding
circulator pumps and encouraged the publishing of a NOPR and a final
rule by the end of 2017. (Docket No. EERE-2016-BT-STD-0004, HI, No.103
at p. 1) In response to an early assessment review RFI published
September 28, 2020 regarding the existing test procedures for general
pumps (85 FR 60734, ``September 2020 Early Assessment RFI''), HI
commented that it continues to support the recommendations from the
CPWG. (Docket No. EERE-2020-BT-TP-0032, HI, No. 6 at p. 1) NEEA also
referenced the September 2016 CPWG Recommendations and recommended that
DOE adopt test procedures for circulator pumps in the pumps rulemaking
or a separate rulemaking. (Docket No. EERE-2020-BT-TP-0032, NEEA, No. 8
at p. 8)
On May 7, 2021, DOE published a request for information related to
test procedures and energy conservation standards for circulator pumps
and small vertical in-line pumps. 86 FR 24516 (``May 2021 RFI''). DOE
received a number of comments in response to the May 2021 RFI. Table
I.2 lists the commenters along with each commenter's abbreviated name
used throughout this NOPR. Discussion of the

[[Page 72099]]

relevant comments, and DOE's responses, are provided in the appropriate
sections of this document. A parenthetical reference at the end of a
comment quotation or paraphrase provides the location of the item in
the public record. \6\
---------------------------------------------------------------------------

\6\ The parenthetical reference provides a reference for
information located in the docket of DOE's rulemaking to develop
test procedures for circulator pumps. (Docket No. EERE-2016-BT-STD-
0004, which is maintained at <a href="http://www.regulations.gov">www.regulations.gov</a>). The references
are arranged as follows: (commenter name, comment docket ID number,
page of that document).

Table I.2--Written Comments Received in Response to May 2021 RFI
------------------------------------------------------------------------
Reference in this
Commenter(s) NOPR Commenter type
------------------------------------------------------------------------
Hydraulic Institute.............. HI................ Trade
Association.
People's Republic of China....... China............. Country.
Grundfos Americas Corporation.... Grundfos.......... Manufacturer.
Appliance Standards Awareness Advocates......... Efficiency
Project, American Council for an Organization.
Energy-Efficient Economy,
Natural Resources Defense
Council.
Northwest Energy Efficiency NEEA.............. Efficiency
Alliance. Organization.
Pacific Gas and Electric Company, CA IOUs........... Utility.
San Diego Gas and Electric, and
Southern California Edison;
collectively, the California
Investor-Owned Utilities.
Anonymous Commenter.............. N/A............... Anonymous \7\.
------------------------------------------------------------------------

The comments in response to the RFI expressed support for
considering small vertical in-line pumps in the commercial and
industrial pumps rulemaking rather than in the circulator pump
rulemaking. (HI, No. 112 at p. 3; Grundfos, No. 113 at p. 2; CA IOUs,
No. 116 at p. 6; NEEA, No. 115 at p. 4). As such, the scope of this
NOPR is limited to circulator pumps.
---------------------------------------------------------------------------

\7\ The Anonymous comment did not substantively address the
subject of this rulemaking.
---------------------------------------------------------------------------

II. Synopsis of the Notice of Proposed Rulemaking

In this NOPR, DOE proposes to establish in subpart Y to 10 CFR part
431 a test procedure that includes methods to (1) measure the
performance of the covered equipment and (2) use the measured results
to calculate a circulator energy index (``CEI'') to represent the
weighted average electric input power to the driver over a specified
load profile, normalized with respect to a circulator pump serving the
same hydraulic load that has a specified minimum performance level.\8\
The proposed test procedure and metric are similar in concept to the
test procedure and metric established in subpart Y to 10 CFR part 431
for general pumps.
---------------------------------------------------------------------------

\8\ The performance of a comparable pump that has a specified
minimum performance level is referred to as the circulator energy
rating (``CER'').
---------------------------------------------------------------------------

DOE's proposed test method for circulator pumps includes
measurements of head, flow rate, and driver power input, all of which
are required to calculate CEI, as well as other quantities to
characterize the rated circulator pump performance (e.g., pump power
output (hydraulic horsepower), speed, wire-to-water efficiency). For
consistent and uniform measurement of these values, DOE proposes to
incorporate the test methods established in HI 40.6-2021, ``Methods for
Rotodynamic Pump Efficiency Testing,'' with certain exceptions. DOE
reviewed the relevant sections of HI 40.6-2021 and determined that HI
40.6-2021, in conjunction with the additional test methods and
calculations proposed in this test procedure, would produce test
results that reflect the energy efficiency, energy use, or estimated
operating costs of a circulator pump during a representative average
use cycle. (42 U.S.C. 6314(a)(2)) DOE also reviewed the burdens
associated with conducting the proposed circulator pump test procedure,
including HI 40.6-2021, and, based on the results of such analysis,
found that the proposed test procedure would not be unduly burdensome
to conduct. (42 U.S.C. 6314(a)(2)) DOE's analysis of the burdens
associated with the proposed test procedure is presented in section
III.H.1 of this document.
DOE also considered HI 41.5-2021, ``Hydraulic Institute Program
Guideline for Circulator Pump Energy Rating Program,'' which defines
the requirements to participate in and list circulator pumps in the
Hydraulic Institute Energy Rating Program and which references HI 40.6-
2021 while providing additional instructions for testing circulator
pumps to determine an Energy Rating value. In response to the May 2021
RFI, HI recommended that DOE incorporate by reference HI 41.5 as the
test procedure. (HI, No. 112 at p. 2) DOE has tentatively determined
not to directly incorporate HI 41.5-2021. Unlike HI 40.6-2021, which is
an industry test standard, HI 41.5-2021 is a guideline for
participation in an industry program, and includes many provisions not
relevant to DOE. DOE has preliminarily determined that its proposed
test methods and calculations that supplement the proposed
incorporation by reference of HI 40.6-2021, as discussed in sections
III.D and III.E.2.c, are consistent with HI 41.5-2021.
This NOPR also proposes requirements regarding the sampling plan
and representations for circulator pumps at subpart B of part 429 of
Title 10 of the Code of Federal Regulations. The sampling plan
requirements are similar to those established for general pumps. DOE
also proposes provisions regarding allowable representations of energy
consumption, energy efficiency, and other relevant metrics
manufacturers may make regarding circulator pump performance (as
discussed in section III.G of this document).
Were the proposed test procedure and associated provisions made
final, manufacturers would not be required to test according to the DOE
test procedure until such time as compliance is required with energy
conservation standards for circulator pumps, should DOE establish such
standards. Were DOE to establish test procedures as proposed,
manufacturers choosing to make voluntary representations would be
required to test the subject pump according to the established test
procedure, and any such representations would have to fairly disclose
the results of such testing.

III. Discussion

In this TP NOPR, DOE proposes to establish in subpart Y of part 431
test procedures and related definitions for circulator pumps, amend 10
CFR 429.59 to establish sampling plans for this equipment, and
establish enforcement provisions for this equipment in 10 CFR 429.110
and 10 CFR 429.134. The

[[Page 72100]]

proposed amendments are summarized in Table III.1.

Table III.1--Summary of Proposals in This TP NOPR, Their Location Within the Code of Federal Regulations, and
the Applicable Preamble Discussion
----------------------------------------------------------------------------------------------------------------
Applicable preamble
Topic Location in CFR Summary of proposals discussion
----------------------------------------------------------------------------------------------------------------
Definitions........................ 10 CFR 431.462........ Define circulator pump as Sections III.B.2,
well as varieties of III.B.3, III.B.4,
circulator pumps and III.B.5, III.B.7,
circulator pump controls. III.AIII.D.1.
Test Procedure..................... 10 CFR 431.464 & Establish CEI as the metric Sections III.C, III.D,
Appendix D. for circulator pumps, and III.E.
incorporate by reference
HI 40.6-2021, and provide
additional instructions
for determining the CEI
(and other applicable
performance
characteristics) for
circulator pumps.
Sampling Plan...................... 10 CFR 429.59......... Specify the minimum number Section III.F.
of circulator pumps to be
tested to rate a basic
model and determination of
representative values.
Enforcement Provisions............. 10 CFR 429.110 & 10 Establish a method for Section III.F.
CFR 429.134. determining compliance of
circulator pump basic
models.
----------------------------------------------------------------------------------------------------------------

The following sections discuss DOE's specific proposals regarding
circulator pumps. Section III.B presents DOE's proposals related to
definitions for categorizing and testing of circulator pumps. Sections
III.C, III.D, III.E, and III.F discuss the proposed metric, test
procedure, and certification and enforcement provisions for tested
circulator pump models. Section III.G discusses representations of
energy use and energy efficiency for circulator pumps.

A. General Comments

In response to the May 2021 RFI, the Advocates urged DOE to adopt
test procedures for circulator pumps based on the September and
November 2016 CPWG Recommendations. (Advocates, No. 114 at p. 1)
Grundfos supported the regulation of circulator products. (Grundfos,
No. 113 at p. 1) The CA IOUs stated that other than the test procedure
update to HI 41.5-2021 (discussed in section III.E.1 of this NOPR),
they supported the adoption of the September and November 2016 CPWG
Recommendations, including the provisions for circulator pump
definitions, control type definitions, reference curve, weighting
points, and the definition of CEI. (CA IOUs, No. 116 at p. 5) NEEA
supported the September and November 2016 CPWG Recommendations with a
few minor modifications based on additional information or lessons
learned from years of experience implementing its circulator pump
energy efficiency program. (NEEA, No. 115 at p.2) NEEA also commented
that it has been working with HI and manufacturers to test and rate
circulator pumps using HI's voluntary rating standard developed based
on the CPWG term sheet. (Id.)

B. Scope and Definitions

As discussed, in the January 2016 TP final rule, DOE adopted a
definition for ``pump,'' as well as definitions for other pump
component- and configuration-related definitions. 81 FR 4086, 4090-94
(Jan. 25, 2016); see also 10 CFR 431.462. DOE recognized circulator
pumps as a category of pumps, but DOE did not define ``circulator
pump''. 81 FR 4086, 4097.
In this NOPR, DOE is proposing a definition of circulator pump,
associated definitions for categories of circulator pumps, as well as
related definitions for control varieties of circulator pumps (see
sections III.B.2, III.B.4, III.B.5 and III.D.1 of this NOPR). These
definitions are necessary to establish the scope of applicability of
the proposed circulator pump test procedure. The scope of the proposed
test procedure is discussed in section III.B.6 of this document.
1. CPWG Recommendations
As discussed in the May 2021 RFI, the September 2016 Circulator
Pump Recommendations addressed the scope of a circulator pumps
rulemaking. Specifically, the CPWG recommended that the scope of a
circulator pumps test procedure and energy conservation standards cover
clean water pumps (as defined at 10 CFR 431.462) distributed in
commerce with or without a volute \9\ and that are one of the following
categories: Wet rotor circulator pumps, dry rotor close-coupled
circulator pumps, and dry rotor mechanically-coupled circulator pumps.
The CPWG also recommended that the scope exclude submersible pumps and
header pumps. 86 FR 24516, 24520; (Docket No. EERE-2016-BT-STD-0004,
No. 58, Recommendations #1A, 2A and 2B at p. 1-2) The CPWG also
recommended the following definitions relevant to scope:
---------------------------------------------------------------------------

\9\ Volutes are also sometimes referred to as a ``housing'' or
``casing.''
---------------------------------------------------------------------------

Wet rotor circulator pump means a single stage, rotodynamic, close-
coupled, wet rotor pump. Examples include, but are not limited to,
pumps generally referred to in industry as CP1.
Dry rotor, two-piece circulator pump means a single stage,
rotodynamic, single-axis flow, close-coupled, dry rotor pump that:
(1) Has a hydraulic power less than or equal to five horsepower at
best efficiency point at full impeller diameter,
(2) is distributed in commerce with a horizontal motor, and
(3) discharges the pumped liquid through a volute in a plane
perpendicular to the shaft. Examples include, but are not limited to,
pumps generally referred to in industry as CP2.
Dry rotor, three-piece circulator pump means a single stage,
rotodynamic, single-axis flow, mechanically-coupled, dry rotor pump
that:
(1) Has a hydraulic power less than or equal to five horsepower at
best efficiency point at full impeller diameter,
(2) is distributed in commerce with a horizontal motor, and
(3) discharges the pumped liquid through a volute in a plane
perpendicular to the shaft. Examples include, but are not limited to,
pumps generally referred to in industry as CP3.
Horizontal motor means a motor that requires the motor shaft to be
in a horizontal position to function as designed under typical
operating conditions, as specified in manufacturer literature.

[[Page 72101]]

Submersible pump means a pump that is designed to be operated with
the motor and bare pump fully submerged in the pumped liquid.
Header pump means a pump that consists of a circulator-less-volute
intended to be installed in an original equipment manufacturer
(``OEM'') piece of equipment that serves as the volute. (Docket No.
EERE-2016-BT-STD-0004, No. 58, Recommendations #2B, 3A, and 3B at p. 2-
3); 86 FR 24516, 24520.

DOE notes that generally these definitions rely on terms previously
defined in the January 2016 TP final rule, including ``close-coupled
pump,'' ``mechanically-coupled pump,'' ``dry rotor pump,'' ``single
axis flow pump,'' and ``rotodynamic pump.'' 81 FR 4086, 4146-4147; 10
CFR 431.462. In addition, the recommended definition for submersible
pump is the same as that already defined in a 2017 test procedure final
rule for dedicated-purpose pool pumps (``August 2017 DPPP TP final
rule''). 82 FR 36858, 36922 (August 7, 2017);10 CFR 431.462.
DOE discusses the proposed definitions of wet rotor circulator
pump; dry rotor, two-piece circulator pump; dry rotor, three-piece
circulator pump; and horizontal motor in section III.B.3, header pump
in section III.B.4, and submersible pump in section III.B.6 of this
NOPR.
2. Definition of Circulator Pump
Circulator pumps are a subset of small, IL pumps that are designed
to provide a small amount of head to overcome pipe friction losses in a
water circulation system for hydronic heating or cooling and potable
hot water recirculation. During the CPWG meetings, the CPWG discussed
the applications and utilities that circulator pumps serve and the
distinctions in the designs of circulator pump varieties.
In defining circulator pump, the CPWG reviewed the descriptions
established in the standard American National Standards Institute
(``ANSI'')/HI 1.1-1.2-2014 standard (``ANSI/HI 1.1-1.2-2014''),
``Rotodynamic Centrifugal Pumps for Nomenclature and Definitions.''
(Docket No. EERE-2016-BT-STD-0004, No. 64 at pp.41-43) Section
1.1.3.3.5 of ANSI/HI 1.1-1.2-2014 characterizes circulator pumps based
on the following four unique features: (1) Rotating assemblies that
must be horizontally mounted; (2) being fully supported in-line by the
system piping; (3) utilizing special-purpose motors unique to this pump
type; and (4) having a motor shaft power that does not exceed 3.75
kilowatts (``kW'') (5 horsepower (``hp'')).
Sections 1.1.3.3.5.1-2 of ANSI/HI 1.1-1.2-2014 provide definitions
for three unique types of circulator pumps. These three unique
circulator pump varieties are based on two main characteristics: (1)
Whether the motor is isolated from or immersed in the pumped liquid,
and (2) how the impeller and motor are connected. Regarding the first
characteristic, a circulator pump may be wet rotor, meaning that the
motor rotor is immersed in the pumped liquid during operation; or dry
rotor, meaning that the pump is not immersed in the pumped liquid. Dry
rotor pumps typically include a mechanical seal that isolates the motor
rotor from the pumped liquid.
The second characteristic, which pertains to how the impeller and
motor are connected, further subdivides wet rotor and dry rotor
circulator pumps into close-coupled or mechanically-coupled varieties.
A close-coupled pump has a motor and impeller that share a common
shaft, while a mechanically-coupled pump features an impeller that has
its own shaft that is connected by mechanical means to the motor shaft.
Based on these differentiating features, Sections 1.1.3.3.5.1-2 of
ANSI/HI 1.1-1.2-2014 defines the following circulator pump varieties:
<bullet> Close-coupled circulator pumps (CP1 and CP2)--Close-
coupled circulator pumps may have driver elements that are immersed in
the pumped fluid (CP1) or isolated by a mechanical seal (CP2). The
rotating assembly shares a common shaft; the bearing(s) of the rotating
assembly absorb all pump hydraulic loads (axial and radial). The driver
is aligned and assembled directly to the pump unit with machined fits.
<bullet> Flexibly-coupled circulator pumps (CP3)--In flexibly-
coupledcirculator pumps, the pump has a shaft supported by its own
bearings that absorb all pump hydraulic loads (axial and radial). The
driver is aligned and assembled directly to the pump unit with machined
fits, typically with a resilient mount to damped vibration. The pump
and driver shafts are flexibly coupled via flexible element drive
couplings.\10\
---------------------------------------------------------------------------

\10\ ``Flexibly-coupled'' is a more specific use of the term
``mechanically-coupled''. Consistent with 10 CFR 431.462 and CPWG
recommendations, DOE uses the term ``mechanically-coupled''
throughout the remainder of this notice.
---------------------------------------------------------------------------

Consistent with the ANSI/HI 1.1-1.2-2014 classification, the CPWG
discussed defining three varieties of circulator pumps: (1) Wet rotor
circulator pumps, (2) dry rotor close-coupled circulator pumps, and (3)
dry rotor mechanically-coupled circulator pumps. (Docket No. EERE-2016-
BT-STD-0004, No. 64 at pp.41-43)
The specific definitions for wet rotor circulator pumps and dry
rotor circulator pumps are discussed in the following sections.
The CPWG also discussed the applicability of the recommended test
procedure and standards to circulator pumps distributed in commerce
without a volute. As discussed in more detail in section III.B.4, the
CPWG discussed how some circulator pumps are distributed in commerce
without a volute, either as a replacement for an existing circulator
pump that has failed or to be newly installed with a paired volute in
the field. (Docket No. EERE-2016-BT-STD-0004, No. 74 at pp. 383-407).
In section III.E.2.b, DOE proposes specific instructions regarding how
to test a ``circulator-less-volute.''
To specify that the recommended circulator pump test procedure and
standards are intended to apply to circulator pumps, with or without a
volute, the CPWG recommended adding such language to the recommended
circulator pump definition. (Docket No. EERE-2016-BT-STD-0004, No. 66
at pp. 156-164). The CPWG also recommended to define circulator pump as
being comprised of the following pump categories distributed in
commerce with or without a volute: Wet rotor circulator pumps, dry
rotor close-coupled circulator pumps, and dry rotor mechanically-
coupled circulator pumps. (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendation #1A at p. 1)
DOE notes that the terminology in the CPWG recommended definition
for circulator pump does not match the terminology in the CPWG
recommended definitions for the circulator pump categories.
Specifically, the recommended circulator pump definition includes ``dry
rotor close-coupled circulator pumps'' and ``dry rotor mechanically-
coupled circulator pumps,'' while the recommended defined terms are
``dry rotor, two-piece circulator pump'' and ``dry rotor, three-piece
circulator pumps.'' (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendation #1A, 3A, and 3B at pp. 1-3) Those defined terms
reference close-coupling and mechanical-coupling, respectively. DOE
notes that HI 41.5-2021 defines circulator pump in section 41.5.1.5.1
as a wet rotor circulator pump (CP1); a dry rotor, two-piece circulator
pump (CP2); or a dry rotor three-piece circulator pump (CP3). Based on
their use in the industry test procedure, DOE understands that ``two-
piece'' and ``three-piece'' are the preferred industry terms over the
terms ``close-coupled'' and ``mechanically-

[[Page 72102]]

coupled,'' and has proposed the use of the industry terms.
DOE is proposing a definition of circulator pump at 10 CFR 431.462
consistent with the definition recommended by the CPWG. Specifically,
DOE proposes the following definition for circulator pump:
Circulator pump is a pump that is either a wet rotor circulator
pump; a dry rotor, two-piece circulator pump; or a dry rotor, three-
piece circulator pump. A circulator pump may be distributed in commerce
with or without a volute.
DOE requests comment on the proposed definition for circulator
pump.
The definitions of the pump categories that comprise the scope of
``circulator pump'' are addressed in the following section. In response
to the May 2021 RFI, China asserted that the range and definition of
circulator pumps is not clear and that schematic diagrams should be
provided for each product on the basis of their text description.
(China, No. 111 at p. 3) DOE believes that the proposed definition of
circulator pump, in combination with the proposed definitions of the
three primary kinds of circulator pumps in the following section,
sufficiently address the range of circulator pumps, and that schematic
diagrams would not provide additional benefit.
3. Definition of Circulator Pump Varieties
In the May 2021 RFI, DOE requested comment on the CPWG's
recommended definitions for wet rotor circulator pump; dry rotor, two-
piece circulator pump; dry rotor, three-piece circulator pump; and
horizontal motor, including whether any changes in the market since the
CPWG's recommendations would affect the recommended definitions and
scope. 86 FR 24516, 24520-24521.
HI, Grundfos, and the CA IOUs generally agreed with the CPWG's
recommended definitions for these varieties of circulator pumps. (HI,
No. 112 at p. 2; Grundfos, No. 113 at p. 1; CA IOUs, No. 116 at p. 5)
Other comments expressed support for the CPWG recommendations
generally, as discussed in section III.A of this document.
As discussed previously, the CPWG recommended definitions for wet
rotor circulator pump; dry rotor, two-piece circulator pump; and dry
rotor, three-piece circulator pump were based on review of the
descriptions of circulator pump categories established in the standard
ANSI/HI 1.1-1.2-2014. DOE notes that the updated version of this
industry standard, ANSI/HI 14.1-14.2-2019, ``Rotodynamic Pumps for
Nomenclature and Definitions,'' has revised the descriptions of
circulator pump categories to be identical to the CPWG recommended
definitions, and section 41.5.1.5.1 of HI 41.5-2021 also includes
definitions identical to the CPWG recommended definitions. DOE has
reviewed the CPWG recommended definitions and has tentatively
determined that these definitions appropriately distinguish the
varieties of circulator pumps available on the market and as originally
described in the industry standard ANSI/HI 1.1-1.2-2014.
Based on the discussion in the prior paragraphs, DOE proposes to
adopt definitions for wet rotor circulator pump; dry rotor, two-piece
circulator pump; and dry rotor, three-piece circulator pump at 10 CFR
431.462 as recommended by the CPWG and supported by stakeholder
comments.
DOE currently defines a ``horizontal motor'' as a motor that
requires the motor shaft to be in a horizontal position to function as
designed, as specified in the manufacturer literature. 10 CFR 431.462.
The definition of ``horizontal motor'' is used in 10 CFR 431.462 to
exclude certain pumps from the IL pump category.\11\ The definition of
``horizontal motor'' recommended by the CPWG includes the additional
phrase ``under typical operating conditions'' to qualify ``function as
designed.'' The CPWG discussed that this qualifier was added to address
the potential that a motor would not be covered as a horizontal motor
if a manufacturer were to advertise its circulator pump as being able
to be installed in a non-horizontal orientation under certain
conditions, such as high operating pressure (i.e., conditions other
than typical conditions). (Docket No. EERE-2016-BT-STD-0004, No. 64 at
pp. 75-83) The CPWG discussed that the requirement to consider motor
installation in the context of typical operating conditions, as
specified in the manufacturer literature, would address this potential.
(Docket No. EERE-2016-BT-STD-0004, No. 66 at pp. 55-57) 86 FR 24516,
24520. DOE did not receive any comments on the definition of horizontal
motor in response to the May 2021 RFI.
---------------------------------------------------------------------------

\11\ The definition of IL pumps includes the following sentence:
``Such pumps do not include pumps that are mechanically coupled or
close-coupled, have a pump power output that is less than or equal
to 5 hp at BEP at full impeller diameter, and are distributed in
commerce with a horizontal motor.'' 10 CFR 431.462.
---------------------------------------------------------------------------

DOE has reviewed the horizontal motor definitions and has
tentatively concluded that the existing definition of horizontal motor
in 10 CFR 431.462 could benefit from additional specificity. However,
DOE does not believe the term ``typical operating conditions''
recommended by the CPWG provides sufficient specificity, as the term
could refer to any conditions specified in the manufacturer's manual.
In order to address the concern that a pump with a horizontal motor
would be considered an IL pump instead of a circulator pump if the
motor must be non-horizontal under non-typical conditions such as high
operating pressure, DOE instead proposes the following definition of
horizontal motor, consistent with the intent of the CPWG:

Horizontal motor means a motor, for which the motor shaft
position when functioning under operating conditions specified in
manufacturer literature, includes a horizontal position.

DOE has tentatively concluded that this proposed update to the
horizontal motor definition would provide additional specificity, but
would not in practice change the pumps currently excluded from the IL
pump definition (and now proposed to be included in the circulator pump
definition) through use of the term.
DOE requests comment on the proposed definition for horizontal
motor, including whether it meets the intent of the CPWG or whether it
would include other motors not intended to be captured in the
definition.
4. Definition of Circulator-Less-Volute and Header Pump
In the May 2021 RFI, DOE discussed that some circulator pumps are
distributed in commerce as a complete assembly with a motor, impeller,
and volute, while other circulator pumps are distributed in commerce
with a motor and impeller, but without a volute (herein referred to as
``circulators-less-volute''). Some circulators-less-volute are solely
intended to be installed in other equipment, such as a boiler, using a
cast piece in the other piece of equipment as the volute, while others
can be installed as a replacement for a failed circulator pump in an
existing system or newly installed with a paired volute in the field.
86 FR 24516, 24521; (Docket No. EERE-2016-BT-STD-0004, No. 47 at pp.
371-372; Docket No. EERE-2016-BT-STD-0004, No. 70 at p. 99) As
discussed in the May 2021 RFI, CPWG asserted that circulator pumps
distributed in commerce without volutes meet the definition of pump,
and that not subjecting such equipment to test procedures and standards
would represent a significant loophole. 86 FR 24516, 24521; (Docket No.
EERE-2016-

[[Page 72103]]

BT-STD-0004, No. 70 at pp. 89-91; No. 74 at pp.383-403) The CPWG also
discussed that including circulators-less-volute within the scope of
DOE regulation is consistent with the treatment of circulator pumps
under the European Union's regulations \12\ which applies to circulator
pumps ``with or without housing.'' (Docket No. EERE-2016-BT-STD-0004,
No. 74 at pp. 373-376)
---------------------------------------------------------------------------

\12\ See EC No 622/2012; <a href="https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=celex:32012R0622">https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=celex:32012R0622</a>.
---------------------------------------------------------------------------

As noted in the May 2021 RFI, the CPWG also discussed that
circulators-less-volute that are solely intended to be installed in
other equipment use the other equipment as the volute, and do not have
a matching volute that is separately distributed in commerce and,
therefore, would not pose the same loophole risk. According to the
CPWG, such pumps would also be difficult to test and rate.
Specifically, the CPWG discussed that circulator pump manufacturers
would not have access to or design authority for the volute design. In
addition, the circulator pump could not be tested as a standalone
circulator pump because the volute would be unable to be removed from
the other equipment, and no paired volute would be distributed in
commerce with which the header pump could be tested. According to the
CPWG, such equipment would potentially require extensive and burdensome
equipment to test appropriately. As such, the CPWG recommended
excluding circulator pumps that are distributed in commerce exclusively
to be incorporated into other OEM equipment, such as boilers or pool
heaters. (Docket No. EERE-2016-BT-STD-0004, No. 74 at pp. 413-416) 86
FR 24516, 24521.
As stated in the May 2021 RFI, the CPWG suggested referring to
circulator-less-volute that are intended solely for installation in
another piece of equipment and do not have a paired volute that is
distributed in commerce as ``header pumps.'' (Docket No. EERE-2016-BT-
STD-0004, No. 74 at pp. 384-386). The CPWG recommended defining
``header pump'' as a pump that consists of a circulator-less-volute
intended to be installed in an OEM piece of equipment that serves as
the volute, and to exclude them from the recommended circulator pump
test procedure and standards. (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendation #2B at p. 2); 86 FR 24516, 24521. The CPWG also
recommended that for header pumps distributed in commerce with
regulated equipment, DOE should consider modifying the test procedure
and metric for such regulated equipment during the next round of
applicable rulemakings to account for the energy use of header pumps in
a modified metric. For header pumps distributed in commerce with non-
regulated equipment, the CPWG recommended that DOE should consider test
procedures and standards for such pumps or equipment at a later date.
(Docket No. EERE-2016-BT-STD-0004, No. 58 Non-Binding Recommendation to
the Secretary #2 at p. 10)
In the May 2021 RFI, DOE requested comment on the definition of
header pump. 86 FR 24516, 24521. HI agreed with the CPWG recommended
definition of ``header pump,'' stating that no substantive changes have
occurred in the market, and that such pumps should be excluded from
regulation. (HI, No. 112 at p. 2) NEEA supported the recommended
definition of ``header pump'' and the recommended exclusion of them,
noting that they are challenging to test. NEEA also commented that DOE
should monitor the market for header pumps and make sure it does not
become a loophole after regulation. (NEEA, No. 115 at p. 3) Grundfos
stated that no change to the definition is warranted, but that header
pumps should be regulated in the same way that circulators-less-volute
are regulated; i.e., by requiring a reference volute for testing, as is
required in the EU, in order to avoid creating a loophole. (Grundfos,
No. 113 at p. 1-2). China stated that the test method for header pumps
has not been provided and that DOE should define the test method for
these pumps. (China, No. 111 at p. 3)
DOE notes that HI 41.5-2021 does not address either header pumps or
circulators-less-volute. DOE tentatively agrees that a circulator-less-
volute designed solely for use as a component in a separate piece of
equipment should be distinguished from circulators-less-volute
generally for the purpose of the proposed test procedure for the
reasons discussed by the CPWG. As discussed in section III.E.2.b, the
CPWG recommended specific test procedure provisions for circulators-
less-volute that are not designed solely for installation in a separate
piece of equipment (i.e., a header pump). (Docket No. EERE-2016-BT-STD-
0004, No. 58 Recommendation #12 at p. 2) To provide a distinction
between a circulator-less-volute and a header pump, DOE proposes
additional detail within the definition of header pump recommended by
the CPWG and to add a definition of circulator-less-volute to be
mutually exclusive from the definition of a header pump. These
definitions proposed by DOE are as follows:

Header pump means a circulator pump distributed in commerce
without a volute and for which a paired volute is not distributed in
commerce. Whether a paired volute is distributed in commerce will be
determined based on published data, marketing literature, and other
publicly available information.

Circulator-less-volute means a circulator pump distributed in
commerce without a volute and for which a paired volute is also
distributed in commerce. Whether a paired volute is distributed in
commerce will be determined based on published data, marketing
literature, and other publicly available information.
DOE requests comment on the proposed definitions of header pump and
circulator-less-volute.
DOE acknowledges that EU Regulation No 622/2012 includes provisions
to test circulator pumps integrated in products dismantled from the
product and measured with a reference pump housing, which means ``a
pump housing supplied by the manufacturer with inlet and outlet ports
on the same axis and designed to be connected to the pipework of a
heating system or secondary circuit of a cooling distribution system.''
\13\ As stated previously, the CPWG discussed that there would be no
available paired volutes with which to test a header pump, and as such
testing such pumps would require extensive and potentially burdensome
equipment to test appropriately. In its comments recommending that use
of a reference volute should be required for testing header pumps,
Grundfos has not sufficiently addressed these testing concerns for
header pumps raised by the CPWG. In addition, DOE tentatively concludes
that requiring testing of header pumps using a reference volute may
result in a rating that is not representative of its energy use in the
equipment for which it is designed, and that assessing header pump
energy use within broader equipment categories in which they are
embedded, such as boilers, may be more appropriate. As such, DOE is not
proposing to include header pumps in the scope of this test procedure,
and accordingly is not proposing a test method for header pumps.
---------------------------------------------------------------------------

\13\ European Commission Regulation No 622/2012 of 11 July 2012
amending Regulation (EC) No 641/2009 with regard to ecodesign
requirements for glandless standalone circulators and glandless
circulators integrated in products. https://eur-lex.europa.eu/legal-
content/EN/TXT/?uri=CELEX:32012R0622. Accessed 2021-09-21.

---------------------------------------------------------------------------

[[Page 72104]]

5. Definition of On-Demand Circulator Pumps
In the May 2021 RFI, DOE stated that on-demand circulator pumps are
designed to maintain hot water supply within a temperature range by
activating in response to a signal, such as user presence. The CPWG
recommended a definition for ``on-demand circulator pumps'' to be
incorporated as necessary. (Docket No. EERE-2016-BT-STD-0004, No. 98
Non-Binding Recommendation #1 at pp. 4-5) 86 FR 24516, 24521.
Discussion during CPWG meetings suggested that the purpose of
recommending a definition for on-demand circulator pumps would be to
allow for the possibility of considering them as a separate equipment
class with a different standard level, while still applying the metric
and test procedure to them. (Docket No. EERE-2016-BT-STD-0004-0069, p.
199) The CPWG recommended defintion for ``on-demand circulator pumps''
is as follows:
``On-demand circulator pump'' means a circulator pump that is
distributed in commerce with an integral control that:
<bullet> Initiates water circulation based on receiving a signal
from the action of a user [of a fixture or appliance] or sensing the
presence of a user of a fixture and cannot initiate water circulation
based on other inputs, such as water temperature or a pre-set schedule.
<bullet> Automatically terminates water circulation once hot water
has reached the pump or desired fixture.
<bullet> Does not allow the pump to operate when the temperature in
the pipe exceeds 104 [deg]F or for more than 5 minutes continuously.
(Docket No. EERE-2016-BT-STD-0004, No. 98 Non-Binding
Recommendation #1 at pp. 4-5); 86 FR 24516, 24521.
In addition, the CPWG recommended that an on-demand circulator pump
must not be capable of operating without the control without physically
destructive modification of the unit, such as any modification that
would violate the product's standards listing. (Docket No. EERE-2016-
BT-STD-0004, No. 98 Non-Binding Recommendation #1 at p. 5); 86 FR
24516, 24521.
DOE requested comment regarding the CPWG-recommended definition of
``on-demand circulator pump'' and whether it is appropriate to retain
on-demand circulator pumps within the scope of future analysis. 86 FR
24516, 24521.
HI agreed with the recommended definition of on-demand circulator
pumps and stated that the CPWG intention of defining them was for the
purpose of possible exclusion from standards due to limited run hours.
(HI, No. 112 at p. 3) Grundfos commented that on-demand products should
be regulated as circulator pumps because they are built with standard
circulator pumps that incorporate additional features, and that having
them unregulated would create a loophole allowing less-efficient
induction-based products to remain on the market. (Grundfos, No. 113 at
p. 1-2) NEEA agreed with the recommended definition of on-demand
circulator pumps, but did not agree that they should be treated
separately by DOE regulations. NEEA commented that these pumps can save
energy by reducing run time, and that these savings are not addressed
in the recommended test method. NEEA recommended that in a future
rulemaking, DOE consider the potential energy savings from domestic hot
water run-hour controls and consider providing a ratings credit for
circulator pumps equipped with efficient temperature, on-demand, timer,
or learning run-hour controls. (NEEA, No. 115 at p. 4).
DOE notes that HI 41.5-2021 does not address or refer to on-demand
circulator pumps. The CPWG discussed that on-demand controls do not
reduce the speed of the pump, but rather reduce the hours of use. Pumps
with on-demand controls could also have speed controls, which the
recommended metric would capture. (Docket No. EERE-2016-BT-STD-0004-
0069, p. 172-173) In addition, CPWG members discussed that the extent
to which time-based controls are used is unknown (Id. at p. 176), and
that rather than attempting to capture it in the metric, utility
programs could consider prescriptive rebates associated with these
controls. (Id. at p. 178) In addition, CPWG members suggested that
legionella concerns would limit the application of on-demand
controls.\14\ (Id. at p. 195-196)
---------------------------------------------------------------------------

\14\ As discussed in the transcript, situations where water is
stagnant and the temperature drops can result in growth of
legionella.
---------------------------------------------------------------------------

DOE proposes to define on-demand circulator pump at 10 CFR 431.462
as recommended by the CPWG. DOE believes that the recommended added
specification that the on-demand circulator pump must not be capable of
operating without the control without physically destructive
modification of the unit, such as any modification that would violate
the product's standards listing, is already encompassed by the
provision in the recommended definition that the control be
``integral'' and by the definition of ``integral'' in 10 CFR 431.462: a
part of the device that cannot be removed without compromising the
device's function or destroying the physical integrity of the unit.
DOE is not proposing to exclude on-demand circulator pumps from the
scope of the test procedure. At this time, DOE has not considered
developing a credit for these controls, as was suggested in comments.
DOE notes that if on-demand circulator pumps are equipped with other
controls that reduce speed as defined in section III.D.1, they may be
tested according to the relevant test methods rather than using the no
controls test. DOE will consider whether standards are appropriate for
this equipment in a future energy conservation standards rulemaking.
DOE requests comment on its proposal to include on-demand
circulator pumps within the scope of this test procedure. DOE also
requests data and information that would justify a CEI credit for on-
demand circulator pumps.
6. Applicability of Test Procedure Based on Pump Configuration
In addition to recommending specific definitions, the CPWG also
discussed and provided recommendations pertinent to the scope of
applicability of the recommended circulator pumps test procedure. The
CPWG recommended that the scope of the recommended test procedure would
be limited to wet rotor circulator pumps, dry rotor close-coupled
circulator pumps, and dry rotor mechanically-coupled circulator pumps,
as discussed in section III.B.2. (Docket No. EERE-2016-BT-STD-0004, No.
58, Recommendation #1A, at p. 1) The CPWG also recommended to limit the
scope of the circulator pump rulemaking to clean water pumps only and
to exclude header pumps and submersible pumps. (Docket No. EERE-2016-
BT-STD-0004, No. 58 Recommendations #2A and 2B at p. 2)
In the January 2016 TP final rule, DOE established a definition for
``clean water pump.'' 81 FR 4046, 4100 (Jan. 25, 2016). DOE noted that
several common pumps would not meet the definition of clean water
pumps, as they are not designed for pumping clean water, including
wastewater, sump, slurry, or solids handling pumps; pumps designed for
pumping hydrocarbon product fluids; chemical process pumps; and
sanitary pumps. Id. at 4100. The CPWG reviewed this definition and, to
be consistent with the general pumps rulemaking, recommended to limit
the scope of the circulator pump

[[Page 72105]]

rulemaking to clean water pumps only, whereby clean water pump means a
pump that is designed for use in pumping water with a maximum non-
absorbent free solid content of 0.016 pounds per cubic foot (0.25
kilograms per cubic meter), and with a maximum dissolved solid content
of 3.1 pounds per cubic foot (50 kilograms per cubic meter), provided
that the total gas content of the water does not exceed the saturation
volume, and disregarding any additives necessary to prevent the water
from freezing at a minimum of 14 [deg]F (-10 [deg]C), as defined at 10
CFR 431.462. (Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendations
#2A at p. 2) The CPWG discussed how this was important to ensure
certain small, chemical process pumps would be excluded based on the
fact that they are not designed to pump clean water. (Docket No. EERE-
2016-BT-STD-0004, No. 70 at pp. 36-42)
DOE did not receive any comments on the May 2021 RFI related to the
CPWG recommendation to limit scope of the circulator pump rulemaking to
clean water pumps. DOE agrees with the CPWG that limiting the scope of
the circulator pump rulemaking to clean water pumps, consistent with
the scope of general pumps in 10 CFR 431.464, is appropriate.
Regulation of chemical process pumps would require many other
considerations beyond that for clean water pumps, and DOE believes that
excluding small chemical process pumps from the scope of regulation
would not create any loophole risks to the clean water circulator pump
market. DOE proposes to apply the existing clean water pump definition
to circulator pumps, thus limiting the scope of applicability of the
proposed circulator pumps test procedure to circulator pumps that meet
the definition of clean water pump.
Regarding the exclusion of submersible pumps, the CPWG discussed a
variety of close-coupled, wet rotor pumps that are typically used for
decorative water features in swimming pools and ponds. (Docket No.
EERE-2016-BT-STD-0004, No. 70 at pp. 47-63 and No. 47, pp. 523-525) The
CPWG discussed how these decorative water feature pumps might otherwise
meet the definition of a wet rotor circulator pump (see section
III.B.2); however, these pumps are unique from traditional wet rotor
circulator pumps, in that they are submersible pumps and, as such, are
intended to be operated with the entire pump and motor assembly fully
submerged in the pumped liquid. Therefore, the CPWG recommended to
exclude submersible pumps from the scope of applicability of any
circulator pump test procedure and standards. (Docket No. EERE-2016-BT-
STD-0004, No. 74 at pp. 299-303)
In response to the May 2021 RFI, HI agreed with the scope agreed to
by the CPWG. (HI, No. 112 at p. 3)
DOE agrees with the CPWG that submersible decorative water feature
pumps are similar in design to wet rotor circulator pumps in that they
are wet rotor, rotodynamic pumps, but that they are intended to be
operated with the entire pump and motor assembly fully submerged in the
pumped liquid, which presents additional considerations for any test
procedure and energy conservation standards. Given that these
decorative water feature pumps are submersible, DOE does not believe
that if unregulated they would pose any loophole risk to the clean
water circulator pump market. Therefore, DOE proposes to exclude
submersible pumps from the scope of applicability of the circulator
pump test procedure. DOE notes that the definition of submersible pump
recommended by the CPWG is identical to the definition that currently
exists in 10 CFR 431.462, as adopted in the August 2017 DPPP TP final
rule. 82 FR 36858, 36922. As such, DOE is not proposing amendments to
that definition.
As discussed in section III.B.4, DOE tentatively agrees with the
recommended exclusion of header pumps and tentatively agrees with the
inclusion of circulators-less volute. Also, as discussed in section
III.B.5, DOE proposes to include on-demand circulator pumps within the
scope of this test procedure. In summary, DOE proposes that the test
procedure would be applicable to circulator pumps (as defined in
section III.B.2) that are clean water pumps, including circulators-
less-volute and on-demand circulator pumps, and excluding header pumps
and submersible pumps. The specific test methods proposed for
circulator pumps are discussed in more detail in section III.D of this
document.
DOE requests comment on the proposed scope of applicability of the
circulator pump test procedure to circulator pumps that are clean water
pumps, and the exclusion of header pumps and submersible pumps from the
scope of the proposed test procedure.
7. Basic Model
In the course of regulating consumer products and commercial and
industrial equipment, DOE has developed the concept of a ``basic
model'' to determine the specific product or equipment configuration(s)
to which the regulations would apply. For the purposes of applying the
proposed circulator pump regulations, DOE is also proposing to rely on
the definition of ``basic model'' as currently defined at 10 CFR
431.462. Application of the current definition of ``basic model'' would
allow manufacturers of circulator pumps to group similar models within
a basic model to minimize testing burden, while ensuring that key
variables that differentiate circulator pump energy performance or
utility are maintained as separate basic models. As proposed,
manufacturers would be required to test only a representative number of
units of a basic model in lieu of testing every model they manufacture.
As proposed, individual models of circulator pumps would be permitted
to be grouped under a single basic model so long as all grouped models
have the same representative energy performance, which is
representative of the least efficient or most consumptive unit.
Specifically, for pumps, DOE's existing definition of basic model
is as follows:
Basic model means all units of a given class of pump manufactured
by one manufacturer, having the same primary energy source, and having
essentially identical electrical, physical, and functional (or
hydraulic) characteristics that affect energy consumption, energy
efficiency, water consumption, or water efficiency; and, in addition,
for pumps that are subject to the standards specified in 10 CFR
431.465(b), the following provisions also apply:
(1) All variations in numbers of stages of bare RSV and ST pumps
must be considered a single basic model;
(2) Pump models for which the bare pump differs in impeller
diameter, or impeller trim, may be considered a single basic model; and
(3) Pump models for which the bare pump differs in number of stages
or impeller diameter and which are sold with motors (or motors and
controls) of varying horsepower may only be considered a single basic
model if:

(i) For ESCC, ESFM, IL, and RSV pumps, each motor offered in the
basic model has a nominal full load motor efficiency rated at the
Federal minimum (see the current table for NEMA Design B motors at
Sec. 431.25) or the same number of bands above the Federal minimum
for each respective motor horsepower (see Table 3 of appendix A to
subpart Y of this part); or
(ii) For ST pumps, each motor offered in the basic model has a
full load motor efficiency at the default nominal full load
submersible motor efficiency shown in Table 2 of appendix A to
subpart Y of this part or the same number of bands above the default
nominal full load submersible motor efficiency for each respective
motor horsepower (see Table 3 of appendix A to subpart Y of this
part).

[[Page 72106]]

10 CFR 431.462

DOE has reviewed this definition and has tentatively determined
that the general definition is appropriate for circulator pumps. DOE
understands that, like dedicated purpose pool pumps, circulator pumps
are exclusively single-stage pumps and, therefore, the provision
regarding variation in number of stages would not be applicable.
Furthermore, DOE understands that, like each dedicated purpose pool
pump motor model, each circulator pump model is offered with only one
impeller diameter, unlike general pumps for which a given pump model
may be sold with many different impeller diameters that are customized
for each application. Therefore, DOE believes that the provision for
grouping individual pumps that vary only in impeller diameter, or
impeller trim, would also not be applicable to circulator pumps; any
variation in impeller trim would constitute a separate basic model for
circulator pumps. Finally, as neither the multistage nor impeller trim
specifications for basic model designation apply to circulator pumps,
the provision regarding variation in motor horsepower resulting from
variation in either of those characteristics would also not apply to
circulator pumps. Therefore, only the general provisions of the basic
model definition would be applicable to circulator pumps and no
additional provisions specific to circulator pumps would be necessary.
DOE requests comment on the proposed applicability of the
definition of ``basic model'' at 10 CFR 431.462 to circulator pumps and
any characteristics unique to circulator pumps that may necessitate
modifications to that definition.

C. Rating Metric

As discussed in the May 2021 RFI, the CPWG focused on defining a
performance-based metric that was similar to the PEI metric established
for the January 2016 TP final rule. (Docket No. EERE-2016-BT-STD-0004,
No. 64 at pp. 246-247) The CPWG recommended using the
PEI<INF>CIRC</INF> metric, which would be defined as the pump energy
rating (``PER'') for the rated circulator pump model
(``PER<INF>CIRC</INF>''), divided by the PER for a circulator pump that
is minimally compliant with energy conservation standards serving the
same hydraulic load (``PER<INF>CIRC,STD</INF>''). (Docket No. EERE-
2016-BT-STD-0004, No. 58, Recommendation #5 at p. 4); 86 FR 24516,
24522.
The equation for PEI<INF>CIRC</INF> as recommended by the CPWG is
shown in the equation (1):
[GRAPHIC] [TIFF OMITTED] TP20DE21.000

Where:

PER<INF>CIRC</INF> = circulator pump energy rating (hp); and
PER<INF>CIRC,STD</INF> = pump energy rating for a minimally
compliant circulator pump serving the same hydraulic load.
(Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #5 at p.
4); 86 FR 24516, 24522.

As stated in the May 2021 RFI, PER<INF>CIRC</INF> would be
determined as the weighted average input power to the circulator pump
motor or controls, if available, to a given circulator pump over a
number of specified load points. Due to differences in the various
control varieties available with circulator pumps, the CPWG recommended
that each circulator pump control variety have unique weights and test
points that are used in determining PER<INF>CIRC</INF>.\15\ (Docket No.
EERE-2016-BT-STD-0004, No. 58 Recommendations #6A and #6B at pp. 4-6)
86 FR 24516, 24522. The test points, weights, and test methods
necessary for calculating PER<INF>CIRC</INF> for pressure controls,
temperature controls, manual speed controls, external input signal
controls, and circulator pumps with no control (i.e., without external
input signal, manual, pressure, or temperature control) \16\ are
described in section III.D. 86 FR 24516, 24522.
---------------------------------------------------------------------------

\15\ In order to determine weighted average input power, input
power must be measured at multiple test points, and each test point
must be weighted. The test points and weights for each test method
are discussed in section III.D.
\16\ In this document, circulator pumps with ``no controls'' are
also inclusive of other potential control varieties that are not one
of the specifically identified circulator pump control varieties.
Any circulator pump without one of the defined control varieties
would be treated as a circulator pump with no controls, regardless
of whether it is a single-speed circulator pump or has a control
variety not defined in this test procedure. See section III.D.7 of
this document.
---------------------------------------------------------------------------

As recommended by the CPWG, PER<INF>CIRC,STD</INF> would be
determined similarly for all circulator pumps, regardless of control
variety. PER<INF>CIRC,STD</INF> would represent the weighted average
input power to a minimally compliant circulator pump serving the same
hydraulic load. As such, PER<INF>CIRC,STD</INF> would essentially
define the minimally compliant circulator pump performance, such that
the energy conservation standard level would always be defined as 1.00,
and lower numbers would represent better performance. The CPWG
discussed the derivation of PER<INF>CIRC,STD</INF> in the Working Group
negotiations and, ultimately, recommended a standard level that is
nominally equivalent to a single-speed circulator pump equipped with an
electrically commutated motor. (Docket No. EERE-2016-BT-STD-0004, No.
102 at pp. 53-56; Docket No. EERE-2016-BT-STD-0004, No. 98
Recommendations #1 and 2A-D at pp. 1-4); 86 FR 24516, 24522.
The CPWG specified a method for determining PER<INF>CIRC,STD</INF>
with procedures to determine the minimally compliant overall efficiency
at the various test points based on the hydraulic performance of the
rated circulator pump. (Docket No. EERE-2016-BT-STD-0004, No. 98
Recommendations #1 and 2A-D at pp. 1-4); 86 FR 24516, 24522. As
discussed, PER<INF>CIRC,STD</INF> would represent the energy efficiency
of a circulator pump that is minimally compliant with the applicable
energy conservation standard, should DOE establish such a standard.
Were DOE to conduct a rulemaking to propose energy conservation
standards for circulator pumps, DOE would discuss in detail the
derivation of PER<INF>CIRC,STD,</INF> as well as an analysis as
required by EPCA to evaluate any such standard level to determine the
level designed to achieve the maximum improvement in energy efficiency
that is technologically feasible and economically justified, as
required under EPCA.\17\ DOE notes that the recommended method for
determining PER<INF>CIRC,STD</INF> relies on the

[[Page 72107]]

hydraulic horsepower of the rated circulator pump. DOE discusses
measurement of this parameter in section III.G.
---------------------------------------------------------------------------

\17\ For more information on any energy conservation standard
rulemaking for circulator pumps see Docket No. EERE-2016-BT-STD-
0004.
---------------------------------------------------------------------------

DOE requested comment on the CPWG recommendation to adopt
PEI<INF>CIRC</INF> as the metric to characterize the energy use of
certain circulator pumps and on the recommended equation for
PEI<INF>CIRC,</INF> including whether anything in the technology or
market has changed since publication of the 2016 Term Sheets that would
lead to this metric no longer being appropriate. 86 FR 24516, 24522.
In response, HI and Grundfos recommended changing the metric
nomenclature from PEI<INF>CIRC</INF> to CEI (Circulator Energy Index)
to avoid confusion and/or differentiate coverage from the general pump
rule. (HI, No. 112 at p. 3; Grundfos, No. 113 at p. 2) HI similarly
recommended corresponding changes to PER<INF>CIRC</INF> to CER
(Circulatory Energy Rating). (HI, No. 112 at p. 3). As stated in
section III.E.1, the Advocates and NEEA supported adopting HI 41.5-
2021, the industry rating guideline, that includes the updated metric
nomenclature discussed by HI in its comments. (Advocates, No. 114 at p.
1; NEEA, No. 115 at p. 4-5). The CA IOUs also supported modifying the
term sheet to adopt HI 41.5-2021, and supported adopting term sheet
provisions including the definition of CEI. (CA IOUs, No. 116 at p. 2,
5)
DOE agrees with the CPWG that the recommended PEI<INF>CIRC</INF>
metric, as shown in equation (1), will reasonably reflect the energy
use of circulator pumps over a representative average use cycle. DOE
also agrees with commenters that changing the name of the metric to CEI
will reduce possibility for confusion. As such, DOE proposes to adopt
the CEI metric as the performance-based metric for representing the
energy performance of circulator pumps, as defined in equation (2), and
consistent with section 41.5.3.2 of HI 41.5-2021. DOE notes that while
HI 41.5-2021 defines the denominator as CER<INF>REF</INF>, DOE believes
that the terminology CER<INF>STD</INF> is more reflective of the
Federal energy conservation standards. Any standards considered for any
circulator pumps for which the CEI is applicable would use this metric
as a basis for the standard level.
[GRAPHIC] [TIFF OMITTED] TP20DE21.001

Where:

CER = circulator energy rating (hp); and
CER<INF>STD</INF> = circulator energy rating for a minimally
compliant circulator pump serving the same hydraulic load.

DOE requests comment on its proposal to adopt CEI as the metric to
characterize the energy use of certain circulator pumps and on the
proposed equation for CEI.

D. Test Methods for Different Circulator Pump Categories and Control
Varieties

Many circulator pumps are sold with a variable speed drive and
controls (i.e., logic or user interface) with various control
strategies that reduce the required power input at a given flow rate to
save energy. The primary varieties of control recommended by the CPWG
include manual speed controls, pressure controls, temperature controls,
and external input signal controls. (Docket No. EERE-2016-BT-STD-0004,
No. 58 Recommendations #4 at p. 4) In order for the test procedure to
produce results that reflect variations in energy consumption
associated with the various control strategies that could be
implemented in a circulator pump, the CPWG recommended that DOE
establish different test methods for each control variety in the
circulator test procedure. (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendations #6A and #6B at pp. 4-6)
Manual speed controls are controls in which the speed of the motor
is adjusted manually, typically at the time of installation, to match
the system head and flow requirements of the installation.
Pressure controls are controls that use a variable speed drive to
automatically adjust the speed of the motor based on the pressure in
the system at any given time according to a fixed constant or
proportional (i.e., sloped) control curve.\18\ Models with pressure
controls typically provide several fixed control curve options
available to accommodate different systems with varying pressure drops
across different zones. These controls are typically installed in
multi-zone hydronic heating applications to vary the speed of the
circulator pump, based on the number of zones open, in order to achieve
the appropriate flow rate through each zone.
---------------------------------------------------------------------------

\18\ Constant pressure control curves supply the same non-zero
head pressure regardless of flow. Proportional pressure control
curves reduce head in response to a reduction in flow, but maintain
a minimum head pressure at zero flow.
---------------------------------------------------------------------------

Adaptive pressure controls are a specific variety of pressure
controls that use pressure sensors to continually evaluate the head and
flow requirements in the system and adjust the sensitivity of the
control response \19\ to specifically suit the system's head and flow
requirements. In addition to being designed to operate in multi-zone
systems, adaptive pressure controls may also have the ability to
operate in a single zone system, such as a domestic hot water
recirculation system, to adjust for any oversizing that might have
occurred in the design and pump selection process. As such, adaptive
pressure controls have the potential to save more energy than
conventional (i.e. non-adaptive) pressure-based controls.
---------------------------------------------------------------------------

\19\ In adaptive pressure controls, the sensitivity of the
control response is adjusted by changing the slope of the control
curve.
---------------------------------------------------------------------------

Temperature controls are controls that use a variable speed drive
to automatically adjust the speed of the pump continuously over the
operating speed range to respond to a change in temperature in the
system. These controls may be installed in single- or multi-zone
systems and adjust the circulator pump's operating speed to provide the
optimum flow rate based on the heat load in each zone. Specifically,
temperature controls are typically designed to achieve a fixed
temperature drop through the system and will adjust the speed of the
pump to increase or decrease the flow rate to precisely match the
required thermal load (i.e., to maintain the target temperature drop).
Unlike pressure controls, there are no minimum head requirements
inherent to the temperature control, so temperature controls have the
potential to use the least amount of energy to serve a given load.
Finally, external input signal control refers to a system in which
the speed of the circulator pump is controlled by control logic that is
external to the circulator pump. This could be the case

[[Page 72108]]

in circulator pumps that are, for example, designed to be installed in
conjunction with a boiler and are controlled by the boiler's firing
controls, as opposed their own internal control logic.
Section III.D.1 discusses DOE's proposed definitions for each of
these circulator pump control varieties.
Section III.D.2 discusses the proposed reference system curve that
serves as a basis for rating each variety of circulator pump controls.
Sections III.D.3 through III.D.7 discuss the specific test
provisions being proposed for pressure controls, temperature controls,
manual speed controls, external input signal controls, and no
controls,\20\ respectively.
---------------------------------------------------------------------------

\20\ In this document, circulator pumps with ``no controls'' are
also inclusive of other potential control varieties that are not one
of the specifically identified control varieties. See section
III.D.7 of this document.
---------------------------------------------------------------------------

In response to the May 2021 RFI, several stakeholders commented
about components of CEI that differ by control type method. China
stated that DOE should offer the specific data or calculation method
for CER<INF>STD</INF> and have executive consultation among World Trade
Organization members before the procedure is officially published and
implemented. China also commented that the weighted average input power
for CEI is set differently than the international general rules, and
requested that DOE offer scientific evidence for the weight assignment.
(China, No. 111 at p. 3) Grundfos stated that the weights used in
determining CEI should be aligned across control modes to simplify
testing and that the baseline calculation method should match the
control method weights. (Grundfos, No. 113 at p. 3) The CA IOUs
supported the weighting points provided in the CPWG term sheets. (CA
IOUs, No. 116 at p. 5)
In response to China and Grundfos, DOE discusses the weighting
assignments in the individual test methods within this section. In
general, the CPWG recommended unique weights for most control
varieties, which were understood to be representative of their
operation in the field. (See sections III.D.3, III.D.4, III.D.5, and
III.D.6. of this NOPR)
HI 41.5-2021 section 41.5.3 specifies rating the most consumptive
and least consumptive of the control curves that are available on a
circulator pump as shipped. The industry test standard provides an
example stating that if pressure control is the most consumptive option
and multiple pressure control curve settings are provided, the
circulator pump would be tested and rated per the pressure control test
method, but with the most and least consumptive control curves. DOE
notes that this example does not seem consistent with the preceding
text, and that in the HI Energy Rating portal for circulator pumps,\21\
the most consumptive rating is always based on full speed (no
controls), while the least consumptive rating is based on one of the
control varieties on-board, if any.
---------------------------------------------------------------------------

\21\ The HI Energy Rating portal is available at <a href="http://er.pumps.org/circulator/ratings">er.pumps.org/circulator/ratings</a>.
---------------------------------------------------------------------------

In response to the May 2021 RFI, HI stated that for clarity, and to
align with the CPWG negotiated intent (referencing page 473 of the CPWG
transcript from July 13, 2016), DOE should implement the least
consumptive control mode CEI for the regulatory rating. (HI, No. 112 at
p. 2)
NEEA commented that in the context of the CPWG recommendation, they
would expect most manufacturers to rate with the least consumptive
control curve available, which would encourage manufacturers to produce
circulator pumps with efficient controls and would enable utilities to
identify equipment with efficient control options. NEEA also suggested
that DOE also allow circulator pumps with multiple control options to
be rated with the most consumptive control curve available, consistent
with HI 41.5-2021. NEEA stated that allowing circulator pumps to have
multiple ratings would encourage adoption of energy efficient options
and technologies beyond the minimum threshold, while holding all
manufacturers to a consistent standard of performance and providing
information for consumers to fully understand the energy consumption of
the equipment. (NEEA, No. 115 at p. 5)
The CPWG did not make a specific recommendation on how to select
which control mode to use for a rating other than that for pressure
controls, a manufacturer should be able to choose the tested control
curve, when multiple options are available, but should report the
control curve used and method of adjustment (e.g., whether the rating
was achieved through automatic speed adjustment, manual speed
adjustment or through simulated pressure signal) to DOE with
certification reporting. (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendation #9 at p. 7)
If given the option to choose a control variety for rating, DOE
expects that most manufacturers would choose the least consumptive
control curve. DOE reviewed the transcript cited by HI and did not
identify justification that the intent of the CPWG was to recommend
testing the least consumptive control mode. DOE believes that proposing
a least consumptive approach, as suggested by HI, could require
manufacturers to conduct multiple tests to identify the least
consumptive control curve, which may cause additional burden. DOE does
not think it is likely that a requirement to identify the least
consumptive control curve would provide additional benefits to
manufacturers (beyond that from an allowance to choose a control curve
to test) such as an incentive to develop energy efficient control
strategies. DOE proposes the approach presented in the CPWG
recommendation, which would allow manufacturers to select the control
variety used for testing if multiple control varieties are available on
the circulator pump. In response to NEEA's recommendation to also allow
ratings with the most consumptive control curve available, DOE proposes
in this NOPR that manufacturers may select multiple control varieties
with which to test their circulator pumps. DOE will address
certification reporting requirements in any future energy conservation
standard rulemaking.\22\
---------------------------------------------------------------------------

\22\ For more information on any energy conservation standard
rulemaking for circulator pumps see Docket No. EERE-2016-BT-STD-
0004.
---------------------------------------------------------------------------

DOE requests comment on the proposal to allow manufacturers to
select the control variety used for testing if the circulator pump
model is distributed in commerce with multiple control varieties. DOE
specifically requests comment on whether DOE should instead require
manufacturers to test a circulator pump model that offers multiple
control varieties with the least consumptive control variety. DOE also
requests comment on the burden that would be associated with such an
approach.
1. Definitions Related to Circulator Pump Control Varieties
As stated in the May 2021 RFI, the CPWG recommended definitions for
the following control varieties for circulator pumps: Manual speed
control, pressure control, temperature control, and external input
signal control. 86 FR 24516, 24523. The definitions of these pump
control varieties recommended by the CPWG are as follows:
<bullet> Manual speed control means a control (variable speed drive
and user interface) that adjusts the speed of a driver based on manual
user input.
<bullet> Pressure control means a control (variable speed drive and
integrated logic) that automatically adjusts the speed of the driver in
response to pressure.

[[Page 72109]]

<bullet> Temperature control means a control (variable speed drive
and integrated logic) that automatically adjusts the speed of the
driver continuously over the driver operating speed range in response
to temperature.
<bullet> External input signal control means a variable speed drive
that adjusts the speed of the driver in response to an input signal
from an external logic and/or user interface.
(Docket No. EERE-2016-BT-STD-0004, No. 58, Recommendation #4 at p.
4) 86 FR 24516, 24523.
DOE requested comment on the recommended definitions for manual
speed control, pressure control, temperature control, and external
input signal control. 86 FR 24516, 24523.
In response to the May 2020 RFI, HI agreed with the current scope
and definition recommended by the CPWG and noted that the definitions
have not been changed in the adoption of HI 41.5-2021. (HI, No. 112 at
p. 4). Grundfos and the CA IOUs also agreed with these definitions for
control methods (Grundfos, No. 113 at p. 3; CA IOUs, No. 116 at p. 5)
As stated previously, NEEA and the Advocates in general supported the
term sheet recommendations. (Advocates, No. 114. at p. 1; NEEA, No. 115
at p. 2) DOE notes that HI 41.5-2021 section 41.5.1.5.1 includes
definitions for manual speed control, pressure control, temperature
control, and external input signal control that are identical to the
CPWG recommendations.
DOE has reviewed these definitions recommended by the CPWG and
believes that the definitions appropriately describe the
characteristics of the relevant circulator pump controls. Furthermore,
DOE believes these definitions appropriately identify each type of
control for the purpose of determining the applicable test method based
on the characteristics of a circulator pump's control variety.
Therefore, consistent with CPWG recommendations and continued
stakeholder support, DOE proposes to define external input signal
control, manual speed control, pressure control, and temperature
control as recommended by the CPWG and consistent with HI 41.5-2021.
In the May 2021 RFI, DOE noted that the CPWG did not recommend a
definition for adaptive pressure controls, although it did recommend a
separate test procedure for them, because, as discussed by the CPWG,
adaptive pressure controls are able to adjust the slope of the control
curve to fit the system needs through an ongoing learning process
inherent in the software. (Docket No. EERE-2016-BT-STD-0004, No. 72 at
pp. 45-46) 86 FR 24516, 24523.
DOE requested comment on a possible definition for adaptive
pressure control. 86 FR 24516, 24523. Grundfos generally objected to
addressing adaptive pressure control in the DOE test procedure.
(Grundfos, No. 113 at p. 3; see discussion in section III.D.3), but did
not comment specifically on the definition.
DOE notes that HI 41.5-2021 section 41.5.1.5.1 includes the
following definition for adaptive pressure control: ``a pressure
control that adjusts the control curve automatically based on the
conditions of use.'' DOE believes that this definition would benefit
from additional clarity regarding the conditions to which the control
responds; specifically, DOE proposes to define adaptive pressure
control as follows:
Adaptive pressure control means a pressure control that
continuously senses the head requirements in the system in which it is
installed and adjusts the control curve of the pump accordingly.
DOE requests comment on its proposed definition of adaptive
pressure control.
In the May 2021 RFI, DOE requested comment on whether any
additional control variety is now currently on the market and if it
should be considered in this rulemaking. 86 FR 24516, 24523. In
response, HI stated that it is not aware of any additional control
methods. (HI, No. 112 at p. 4) NEEA recommended that in a future
rulemaking, DOE consider the potential energy savings from domestic hot
water controls, especially temperature-based controls. NEEA suggested
that DOE consider providing a CEI credit for circulator pumps equipped
with efficient temperature, on-demand, timer, or learning run-hour
controls. (NEEA, No. 115 at p. 4)
DOE acknowledges that additional controls exist for circulator
pumps that reduce run-time rather than reduce speed. DOE proposes to
limit the promulgation of test methods in this rulemaking to those
control varieties recommended by the CPWG, which include only controls
that reduce speed, and may consider additional control varieties in
future rulemakings. DOE discusses the concept of applying ``credits''
for on-demand controls in section III.B.5 of this document.
2. Reference System Curve
The May 2021 RFI stated that all recommended test methods for
circulator pump control varieties, which involve variable speed control
of the circulator pump, specify test points with respect to a
representative system curve. That is, for circulator pumps with manual
speed controls, pressure controls, temperature controls, or external
input signal controls, a reference system curve is implemented to be
representative of the speed reduction that is possible in a typical
system to provide representative results. For circulator pumps with no
controls, no reference system is required as measurements are taken at
various test points along a pump curve at maximum speed only. 86 FR
24516, 24523.
Such a reference system curve describes the relationship between
the head and the flow at each test point in a typical system.
Additionally, a reference system curve that is representative of a
typical system in which circulator pumps are installed may also allow
for the differentiation of control varieties to be reflected in the
resulting ratings. 86 FR 24516, 24523. The CPWG recommended that DOE
incorporate a quadratic reference system curve, which intersects the
BEP and has a static offset of 20 percent of BEP head, as shown in
equation (3). (Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendations
#8 at pp. 6-7) 86 FR 24516, 24523.
[GRAPHIC] [TIFF OMITTED] TP20DE21.002

Where:

H = the pump total head (ft),
Q = the flow rate (gpm),

[[Page 72110]]

Q<INF>100</INF><not-eq> = flow rate at 100 percent of BEP flow
(gpm), and
H<INF>100</INF><not-eq> = pump total head at 100 percent of BEP flow
(ft).
(Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendations #8 at pp.
6-7); 86 FR 24516, 24523.

In the May 2021 RFI, DOE requested comment on whether the CPWG-
recommended reference system curve shape, including the static offset,
is reasonable for circulator pumps. 86 FR 24516, 24523. HI, Grundfos,
and the CA IOUs agreed with the recommended reference curve. (HI, No.
112 at p. 4; Grundfos, No. 113 at p. 3; CA IOUs, No. 116 at p. 5).
DOE notes that the reference curve in equation (3) is consistent
with HI 41.5-2021, which includes this reference curve in each of the
individual control test methods (sections 41.5.3.4.2 #3d, 41.5.3.4.3
#2, 41.5.3.4.4.1 #2, 41.5.3.4.4.2 #2, and 41.5.3.4.5 #2d). DOE has
tentatively determined that the reference curve established for general
pumps would provide representative results for circulator pumps. As
such, DOE proposes to adopt the reference curve as shown in equation
(3).
3. Pressure Control
As described in the May 2021 RFI, pressure controls are a variety
of circulator pump control in which the variable speed drive is
automatically adjusted based on the pressure in the system. For
example, such controls are common in multi-zone hydronic heating
applications where the flow and speed are adjusted in response to zones
opening or closing. CPWG recommended that for all circulator pumps
distributed in commerce with pressure controls, the PER<INF>CIRC</INF>
should be calculated as the weighted average input power at 25, 50, 75,
and 100 percent of BEP flow with unique weights shown in equation (4):
[GRAPHIC] [TIFF OMITTED] TP20DE21.003

Where:

PER<INF>CIRC</INF> = circulator pump energy rating (hp);
w<INF>i</INF> = weight of 0.05, 0.40, 0.40, and 0.15 at test points
of 25, 50, 75, and 100 percent of BEP flow, respectively;
P<INF>in,i</INF> = power input to the driver at each test point i
(hp); and
i = test point(s), defined as 25, 50, 75, and 100 percent of the
flow at BEP.
(Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendations #6A at pp.
4-5 and #7 at p.6); 86 FR 24516, 24523-24524.

The CPWG recommended the weights of 0.05, 0.40, 0.40, and 0.15 at
test points of 25, 50, 75, and 100 percent of BEP flow, respectively,
based on subcommittee review of other relevant test methods that
document the typical load profile of hydronic heating and/or cooling
applications, including AHRI 550/590-2011 ``Performance Rating Of
Water-Chilling and Heat Pump Water-Heating Packages Using the Vapor
Compression Cycle,'' ASHRAE 103 ``Method of Testing for Annual Fuel
Utilization Efficiency of Residential Central Furnaces and Boilers, and
EN 16297-1:2012 ``Pumps. Rotodynamic pumps. Glandless circulators.
General requirements and procedures for testing and calculation of
energy efficiency index (EEI),'' as well as the fact that pumps with
pressure controls will unlikely operate near BEP flow because systems
are sized to be able to meet the full demand of the design day, which
occurs only on rare occasion.\23\
---------------------------------------------------------------------------

\23\ This discussion took place during a CPWG subcommittee
meeting, so there is no transcript in the docket. This presentation
includes the results from the subcommittee: <a href="https://www.regulations.gov/document/EERE-2016-BT-STD-0004-0027">https://www.regulations.gov/document/EERE-2016-BT-STD-0004-0027</a>.
---------------------------------------------------------------------------

In addition to the test point flow rates, the test method for
pressure controls must also specify the head values (or range of head
values) for evaluation. For pressure controls, the head values
associated with the specified flow rates are determined by the control
curve of the pressure control being evaluated. Traditional pressure
controls typically follow a fixed, linear control curve that can
represent maintenance of constant pressure at a variety of different
flow rates, or can reduce the pressure as the flow is reduced. Often, a
single circulator pump will be equipped with a number of different
pressure control options, as illustrated in Figure III.1.
The CPWG recommended testing circulator pumps with pressure
controls using automatic speed adjustment based on the factory selected
control setting, manual speed adjustment, or simulated pressure signal
to trace a factory selected control curve setting that will achieve the
test point flow rates with a head at or above the reference system
curve. (Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #9 at
p. 7) To test circulator pumps with pressure controls under this
recommendation, manufacturers would select a pressure-based control
curve for the purpose of the test procedure, provided that all of the
head values that result from that are at or above the reference system
curve discussed in section III.D.2. For example, Figure III.1 depicts
three fixed pressure control options (low, medium, and high), but only
the highest pressure control option results in head values that are all
at or above the reference system curve. Under the CPWG's
recommendation, the speed of the pump would be adjusted according to
the selected control curve using one of three methods: Manual speed
adjustment, simulated pressure signal, or automatic adjustment.

[[Page 72111]]

[GRAPHIC] [TIFF OMITTED] TP20DE21.004

The CPWG also recommended that if a circulator pump with pressure
controls is tested with automatic speed adjustment, that the pump can
be manually adjusted to achieve 100 percent BEP flow and head point at
max speed. (Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #9
at p. 7); 86 FR 24516, 24524. DOE interpreted this to mean that the
test point at 100 percent BEP flow and maximum speed may be generated
using a combination of alternative speed control and throttling. This
modification would be necessary in the event the manufacturer-selected
control curve does not intersect the maximum speed pump curve at the
BEP of the pump, as shown in Figure III.1. In such a case, the test
point at 100 percent of BEP flow and maximum speed could be generated
from the control curve at the maximum speed setting of the pump and
throttled to reach the specific test point.
In the May 2021 RFI, DOE requested comment on the recommended test
methods, test points, and weights for circulator pumps with pressure
controls. 86 FR 24516, 24524.
HI recommended that DOE implement the testing methodology in HI
41.5-2021 section 41.5.3.4.2 for pressure control, which does not
require all test points on a control curve to exist above the reference
curve. Specifically, HI asserted that the minimum system control head
should be the value at 25 percent BEP on the reference curve for the
manual control (and pressure control) method. HI stated that it found
that intersecting the pump curve at BEP and requiring the control mode
to be above the reference curve was too limiting. HI asserted that this
approach did not represent the controls available in the market, nor
did it properly demonstrate the benefit of the onboard controls. HI
stated that section 41.5.3.4.2 allows controls to be rated below the
reference curve with power correction back to the reference curve. (HI,
No. 112 at 4) HI stated that this change eliminates the need for all
control curves to exist above the reference curve, allowing for a
better presentation of control curves used in the market and for the
circulator pump CEI values to better represent a pump's capabilities.
(HI, No. 112 at p. 2) HI provided an additional appendix in support of
its recommendation for the changes. (HI, No. 112 at p.11-12) Grundfos
recommended that DOE accept the approach defined in HI 41.5 for
calculating CEI that allows for constant pressure control methods to be
rated across the entire curve. (Grundfos, No. 113 at p. 2)
The CA IOUs stated that experiences with field testing the metric
on circulator pumps in the market led to discovering unintended
challenges of testing both constant and proportional pressure controls
in most applications. The CA IOUs noted that these products generally
operate at head pressure below or significantly below the reference
curve at one or more measurement points; thus, most programmed pressure
control curves in a product are not testable under the

[[Page 72112]]

previous methodology. Some products do not have any pre-set control
methods that meet all the requirements and thus must be tested as
having no controls. The CA IOUs added that all of the below reference
curve performance measurements remain valid after adjustment, since the
adjustment uses an assumed constant efficiency calculation. The CA IOUs
asserted that this ensures that products do not gain any arbitrary
input power advantage from the head pressure below the reference curve
adjustment. The CA IOUs stated that not addressing this issue would
force DOE to grant numerous test procedure waivers. (CA IOUs, No. 116
at pp.2, 4-5)
DOE has reviewed the revised test method for pressure control in
section 41.5.3.4.2 of HI 41.5-2021. DOE notes that HI 41.5-2021 does
not include the CPWG recommendation to allow manual adjustment of
automatic speed adjusted controls to achieve 100 percent BEP flow and
head point at maximum speed (although this provision is included for
adaptive pressure controls, discussed later in this section). As stated
previously, DOE did not understand this recommendation to mean that the
pressure control curve should intersect the pump curve at BEP, which HI
noted in their comments was too limiting. However, section 41.5.3.4.2
#2a-c of HI 41.5-2021 in general allows for throttling in combination
with any of the three recommended methods to adjust speed: Automatic
speed adjustment based on the factory selected control setting, manual
speed adjustment, or simulated pressure signal to trace a factory
selected control curve setting. In addition, as noted by HI, HI 41.5-
2021 also contains a requirement that the control curve setting must
achieve 100 percent BEP flow of the reference curve. DOE understands
this to mean that a control curve cannot include artificial limitations
on speed. Otherwise, DOE understands that any control curve would be
able to achieve 100 percent of BEP flow of the reference curve after
intersecting with the maximum speed curve. Finally, DOE understands
that the provision that the control must produce head equal to or
greater than 25 percent of BEP head at a minimum of one test point is
designed to limit testing of control curves that would not be viable in
the field.
DOE agrees with commenters that it is important for the test method
to capture the variety of pressure controls on the market, and that
correction back to the reference curve would prevent any unfair
advantage among the variety of controls on the market. DOE notes that
in this proposal, all three curves depicted in Figure III.1 could be
used in this test method. For all of these reasons, DOE is proposing a
test method for circulator pumps with pressure controls consistent with
the method included in HI 41.5-2021. Specifically, DOE proposes that
circulator pumps with pressure controls be tested at test points of 25,
50, 75, and 100 percent of BEP flow based on a manufacturer-selected
control curve that is available to the end user, must produce a head
equal to or greater than 25 percent of BEP head at a minimum of one
test point, and must achieve 100 percent BEP flow of the reference
curve. DOE proposes that such the test points may be obtained based on
automatic speed adjustment, manual speed adjustment, or simulated
pressure signal, or a combination of these adjustments, including
throttling. Additionally, DOE proposes that the CEI for circulator
pumps with pressure controls be calculated with the unique weights and
test points as shown in equation (4).
DOE requests comment on the proposed test method for circulator
pumps with pressure controls, including whether DOE's interpretation of
the new provisions in HI 41.5-2021 are accurate.
DOE is aware of some circulator pumps that are equipped with user-
adjustable pressure controls such that the maximum and minimum head
values on the control curve can be set to specifically match the system
into which the pump is being installed. DOE's interpretation HI 41.5-
2021 is that these types of controls are not addressed in the industry
standard. To test such controls, DOE proposes that the maximum and
minimum head values on user-adjustable pressure controls may be
adjusted, if possible, to coincide with a maximum head value at the
pump's BEP and a minimum head value equivalent to 20 percent of the BEP
head value (consistent with the static offset of the proposed reference
system curve). If only the maximum or minimum head value can be
adjusted, DOE proposes that only the adjustable setting would be
adjusted. In either case, DOE also proposes that the settings can be
adjusted for testing only if they are adjustable by the user. DOE
believes that this proposed methodology would result in the most
representative performance of such adjustable controls by preventing
the testing of specifically tuned control options that would not be
representative of likely field performance. DOE notes that further
adjustment to attain 100 percent of BEP head would be required.
In summary, for adjustable pressure controls with user-adjustable
maximum and/or minimum head values, DOE proposes to allow one-time
manual adjustment of the maximum and/or minimum control curve head
values, as applicable, to coincide with a maximum head value at the
pump's BEP and a minimum head value equivalent to 20 percent of the BEP
head value with all subsequent test points taken along the adjusted
control curve.
DOE requests comment on whether specific test provisions for
circulator pumps equipped with user-adjustable pressure controls are
needed, and if so, on the proposed provisions for such pumps.
The CPWG also identified a specific style of pressure control that
adapts the control curve setting dynamically to the system in which it
is installed; the CPWG referred to this style of pressure control as
adaptive pressure controls. (Docket No. EERE-2016-BT-STD-0004, No. 72
at p. 45) As discussed in the introduction to section III.D, adaptive
pressure controls are installed in similar applications as pressure
controls, but can also be effective at reducing the head and flow
provided in single-zone systems to adjust for typical pump oversizing.
Also, due to the ability of adaptive pressure controls to measure and
automatically adjust to the system requirements over time, adaptive
pressure controls can result in optimized performance and energy use as
compared to pressure-based controls. The CPWG noted that current
adaptive pressure controls are learning-based controls that gradually
adjust the pressure control set point over time based on the needs of
the system. (Docket No. EERE-2016-BT-STD-0004, No. 72 at pp. 45-46) As
such, the CPWG recommended separate test methods for pressure controls
and adaptive pressure controls, noting the difference in operation and
control logic between the control varieties. (Docket No. EERE-2016-BT-
STD-0004, No. 73 at p. 176) Specifically, the CPWG discussed that since
adaptive pressure controls gradually adjust the control curve over time
to optimize the pressure control performance for the system in which it
is installed, the test method specified for circulator pumps with
pressure controls was not applicable because there is no fixed pressure
control curve that can be evaluated. (Docket No. EERE-2016-BT-STD-0004,
No. 72 at pp. 45-46) Instead, adaptive pressure controls have a control
``area'' that is defined by a minimum head value (H<INF>auto_min</INF>
and H<INF>set_min</INF>), the maximum speed pump curve, and a maximum
head value (H<INF>set</INF>), as depicted in in Figure III.2.

[[Page 72113]]

[GRAPHIC] [TIFF OMITTED] TP20DE21.005

Within the adaptive pressure control ``area,'' a multitude of
different control curves may be selected based on the detected system
head requirements. Therefore, the CPWG discussed the need to specify
the ``control curve'' within an adaptive pressure control's control
area along which such controls would be evaluated. (Docket No. EERE-
2016-BT-STD-0004, No. 66 at pp. 95-98) For circulator pumps with
adaptive pressure controls, the CPWG recommended that testing be
conducted at the minimum thresholds for head based on manufacturer
literature and through manual speed adjustment to achieve the test
point flow rates with head values at or above the reference curve.
(Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #9 at p. 7);
86 FR 24516, 24524.
For example, in Figure III.2, the CPWG recommended test method
would result in minimum head thresholds of H<INF>auto_min</INF> at no
flow conditions and H<INF>set_min</INF> at maximum flow, essentially
the bottom edge of the adaptive pressure control area. However, DOE
notes that the CPWG also specified that the test points could not be
below the reference system curve (specified in section III.D.2),
similar to pressure controls. Therefore, the CPWG discussed how
adaptive pressure controls would be tested through manual speed
adjustment to test points that are at or above the reference system
curve or minimum head thresholds of the adaptive pressure control area,
whichever is greater. (Docket No. EERE-2016-BT-STD-0004, No. 66 at pp.
95-98) This results in, for example, the test points denoted with the
circles along the minimum pressure setting curve and the reference
system curve in Figure III.2.
In response to the May 2021 RFI, DOE requested comment on the
recommended test methods, test points, and weights for circulator pumps
with adaptive pressure controls. 86 FR 24516, 24524.
In response, the CA IOUs encouraged DOE to incorporate
representative field data for adaptive controls in a future test
method, asserting there may be a minimal relationship between the
preloaded defaults or reference curve and the eventual operating points
of these devices in the field, in aggregate. The CA IOUs further
recommended that DOE collaborate with industry to develop test
procedures for these units to capture energy savings occurring in the
overall marketplace. (CA IOUs, No. 116 at p. 7)
Grundfos commented that adaptive pressure control should not be an
allowed test method in DOE's regulations. Grundfos stated that adaptive
pressure controls cannot be tested in the way they operate. Grundfos
commented that because the recommended test procedure would allow such
pumps to be manually adjusted to the reference curve, a manufacturer
could state that any product has adaptive pressure controls and test
the product in a manner that is not aligned with actual performance.
(Grundfos, No. 113 at p. 3)
DOE notes that the test method for such controls in HI 41.5-2021
(section

[[Page 72114]]

41.5.3.4.2 #4) is consistent with the CPWG recommendation. Section
41.5.3.4.2 #4 also allows for manual adjustment to achieve 100 percent
BEP flow and head point at max speed.
In response to Grundfos, DOE notes that, as recommended by the
CPWG, the proposed test procedure would require minimum head thresholds
to be documented in the manufacturer literature associated with the
given circulator pump model and be accessible based on the capabilities
of the control with which the pump is distributed in commerce. That is,
the minimum head thresholds may be manually set before testing the pump
(similar to adjustable pressure controls), but such adjustment must be
possible on the control with which the circulator pump is distributed
in commerce and described in the manufacturer's literature. DOE
believes this would ensure that the evaluated control threshold is
representative of minimum head values that are realized in the field.
In response to the CA IOUs, DOE welcomes additional field data that
could provide more information to support a future update of any
finalized adaptive control test method. Based on the information
currently available, DOE has tentatively determined that the adaptive
pressure control test method recommended by the CPWG and proposed in
this NOPR is reasonably designed to reflect energy use under typical
operating conditions.
In summary, consistent with HI 41.5-2021, for adaptive pressure
controls, DOE proposes to test at each test point at the minimum
thresholds for head noted in the manufacturer literature or the head
values specified along the reference system curve, whichever is
greater. In addition, although not included in HI 41.5-2021, DOE also
proposes that if the pump does not have a manual control mode
available, the speed would be adjusted based on the pressure control
mode with the lowest head at each load point, and if the selected
pressure control results in a head value below the reference system
curve, the pump would be throttled to achieve a head value at or above
the reference system curve.
DOE requests comment on the proposed test methods for circulator
pumps with adaptive pressure controls, and in particular on the
proposed provisions not included in HI 41.5-2021, including for pumps
without a manual control mode, whether throttling should be allowed to
achieve head above the reference system curve, or instead head should
be allowed below the reference system curve and adjusted back to the
curve, as with other non-adaptive pressure controls. DOE also requests
comment on the HI 41.5-2021 provision for manual adjustment to achieve
100 percent BEP flow and heat point at max speed, which is not included
for other pressure controls.
4. Temperature Control
As previously discussed and as presented in the May 2021 RFI,
temperature controls are controls that automatically adjust the speed
of the variable speed drive in the pump continuously over the operating
speed range to respond to a change in temperature of the operating
fluid in the system. Typically, temperature controls are designed to
achieve a fixed temperature differential between the supply and return
lines and adjust the flow rate through the system by adjusting the
speed to achieve the specified temperature differential. Similar to
pressure controls, temperature controls are also designed primarily for
hydronic heating applications. However, temperature controls may be
installed in single- or multi-zone systems and will optimize the
circulator pump's operating speed to provide the necessary flow rate
based on the heat load in each zone. Unlike pressure controls, there
are no minimum head requirements inherent to the temperature control,
so temperature controls have the potential to use the least amount
energy to serve a given load. 86 FR 24516, 24524.
The CPWG recommended that for circulator pumps distributed in
commerce with temperature controls, PER<INF>CIRC</INF> should be
calculated in the same way and with the same weights as for pressure
controls, as shown in equation (4).(Docket No. EERE-2016-BT-STD-0004,
No. 58 Recommendation #6A at pp. 4-5); 86 FR 24516, 24524.
As temperature controls serve similar hydronic heating applications
as pressure controls, the CPWG assigned the same weights, which are
representative of the loads the circulator pump is serving. (Docket No.
EERE-2016-BT-STD-0004, No. 70 at pp. 113-115) Specifically, for
circulator pumps with temperature controls, the CPWG recommended
weights of 0.05, 0.40, 0.40, and 0.15 at test points of 25, 50, 75, and
100 percent of BEP flow, respectively. (Docket No. EERE-2016-BT-STD-
0004, No. 58 Recommendation #7 at p.6)
Since circulator pumps with temperature controls are not limited by
head requirements present in pressure controls and can match the
required speed to meet the demand of the system, the head values at the
specified flow rates of 25, 50, 75, and 100 percent of BEP flow are not
dictated by the control curve logic. As such, the temperature control
is able to achieve the exact head values at each flow rate described by
the reference system curve (discussed in section III.D.2). Assuming the
reference system curve represents a typical system, testing temperature
controls along the reference system curve represents their likely
performance because temperature controls have the ability to sense and
respond precisely to the load on the system.
In addition to the test points, the CPWG also discussed how
circulator pumps with temperature control should be controlled during
testing. The CPWG discussed how testing temperature controls using
conditioned water would be extremely burdensome and expensive. The CPWG
discussed that providing less burdensome options for testing would
represent a reasonable compromise to reduce the burden associated with
testing temperature controls, while still resulting in representative
energy performance ratings. (Docket No. EERE-2016-BT-STD-0004, No. 70
at pp. 282-288) Therefore, the CPWG recommended that circulator pumps
with temperature controls be tested based on manual speed adjustment or
with a simulated temperature signal to activate the temperature-based
control to achieve the test point flow rates with a head at or above
the reference curve. (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendation #9 at p. 7); 86 FR 24516, 24524.
In the May 2021 RFI, DOE requested comment on the recommended test
methods, test points, and weights for circulator pumps with temperature
controls. Specifically, DOE requested comment on whether the technology
or market for such controls has changed sufficiently since the term
sheet to warrant a different approach. 86 FR 24516, 24524.
HI stated that it was not aware of any technical or market changes.
(HI, No. 112 at p. 4) Grundfos stated that temperature control is a
form of external control (i.e., temperature sensor input to the
controller), and that therefore, temperature control should be removed
and included as part of external control for testing purposes. Grundfos
suggested, however, that in this case manufacturers should be allowed
to identify temperature control on their products. (Grundfos, No. 113
at p. 3-4)
DOE notes that the temperature control test method recommended by
the CPWG is consistent with that in section 41.5.3.4.3 of HI 41.5-2021.
In response to Grundfos, DOE notes that

[[Page 72115]]

the CPWG considered the category of external input signal controls as
separate from temperature controls. Specifically, the CPWG noted that
unlike pressure and temperature controls, for external input signal
controls, the logic that defines how the circulator pump operating
speed is selected in response to some measured variable (e.g.,
temperature, pressure, or boiler fire rate) is not integral to the
circulator as distributed in commerce. Instead, it is part of another
control system, such as a building management system or a boiler
control system. (Docket No. EERE-2016-BT-STD-0004, No. 72 at p. 83-84)
DOE also notes that the test method recommended by the CPWG and in HI
41.5-2021 for circulator pumps with external input signal controls only
and that cannot operate without an external signal control is the same
as the test method for circulator pumps with temperature control.
However, the CPWG recommended, and HI 41.5-2021 included, a different
test method for external input signal controls with other control
varieties or that can be operated without external input signal
control. The reasons for this difference are discussed in section
III.D.6. As such, DOE proposes to remain consistent with the CPWG
recommendations and HI 41.5-2021 regarding specification of a
temperature control test method.
DOE tentatively determines that the CPWG for temperature controls
would allow for temperature controls to be tested in a way that
captures the potential energy savings from this control variety without
being overly burdensome for manufacturers to conduct. Therefore, DOE
proposes to adopt the recommendations of the CPWG to test temperature
controls based on manual speed adjustment or with simulated temperature
signal to activate the temperature-based control to achieve the test
point flow rates with a head at or above the reference system curve.
Additionally, DOE proposes to use the weights and test points shown in
equation (4) for circulator pumps distributed in commerce with
temperature controls.
DOE requests comment on the proposed test methods, test points, and
weights for circulator pumps with temperature controls.
5. Manual Speed Control
As discussed previously and as stated in the May 2021 RFI, manual
speed controls are a control variety for which the speed of the pump is
adjusted manually, typically to one of several pre-set speeds, by a
dial or a control panel to fit the demand of the system within which it
is installed. The CPWG discussed how circulator pumps installed with
manual speed controls are typically only adjusted one time upon
installation, if at all, and will operate at that set speed as if it
were a single-speed circulator pump. As such, many manual speed control
circulator pumps operate at full speed in the field, while a portion of
them may be turned down to a medium or low speed to suit the needs of
the systems. (Docket No. EERE-2016-BT-STD-0004, No. 65 at pp. 131-133);
86 FR 24516, 24524.
Therefore, the CPWG recommended to test circulator pumps with
manual speed controls both: (1) Along the maximum speed circulator pump
curve to achieve the test point flow rates for the max speed input
power values, and (2) based on manual speed adjustment to the lowest
speed setting that will achieve a head at or above the reference curve
at the test point flow rate for the reduced speed input power values.
(Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #9 at p. 7);
86 FR 24516, 24524.
To accomplish a single rating representative of the ``average''
energy use of a manual speed circulator, the CPWG recommended that for
circulator pumps distributed in commerce with manual speed controls,
the PER<INF>CIRC</INF> should be calculated as the weighted average of
P<INF>in,max</INF> (the weighted average input power at specific load
points across the maximum speed curve) and P<INF>in,reduced</INF> (the
weighted average input power at specific load points at reduced speed),
but recommended separate load points and speed factors, as shown in
equations (5), (6), and (7):
[GRAPHIC] [TIFF OMITTED] TP20DE21.006

Where:

PER<INF>CIRC</INF> = circulator pump energy rating (hp);
z<INF>max</INF> = speed factor weight of 0.75;
P<INF>in_max</INF> = weighted average input power at maximum
rotating speed of the circulator (hp), as specified in equation (6);
z<INF>reduced</INF> = speed factor weight of 0.25; and
P<INF>in_reduced</INF> = weighted average input power at reduced
rotating speed of the circulator (hp), as specified in equation (7).
[GRAPHIC] [TIFF OMITTED] TP20DE21.007

Where:

P<INF>in_max</INF> = weighted average input power at maximum speed
of the circulator (hp);
w<INF>i_max</INF> = 0.25;
P<INF>in,i_max</INF> = power input to the driver at maximum rotating
speed of the circulator pump at each test point i (hp); and
i = test point(s), defined as 25, 50, 75, and 100 percent of the
flow at BEP.

[[Page 72116]]

[GRAPHIC] [TIFF OMITTED] TP20DE21.008

Where:

P<INF>in_reduced</INF> = weighted average input power at reduced
speeds of the circulator (hp);
w<INF>i_reduced</INF> = 0.3333;
P<INF>in,i_reduced</INF> = power input to the driver at reduced
rotating speed of the circulator pump at each test point i (hp); and
i = test point(s), defined as 25, 50, and 75 percent of the flow at
BEP of max speed and head values at or above the reference curve.
(Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #6B and 7
at pp. 5-6); 86 FR 24516, 24524-24525.

The CPWG specified the speed factor for maximum speed
(z<INF>max</INF>) and reduced speed (z<INF>reduced</INF>) to represent
the likelihood that the circulator pump would operate at maximum versus
reduced speed, or the likelihood that an installer would turn down the
speed of the circulator pump in the field. The CPWG concluded that
about 75 percent of the time, circulator pumps with manual speed
controls are operated at maximum speed. (Docket No. EERE-2016-BT-STD-
0004, No. 71 at p. 377) Therefore, the CPWG recommended that the speed
factor for maximum speed (z<INF>max</INF>) should be 0.75 and the speed
factor for reduced speed (z<INF>reduced</INF>) should be 0.25. (Docket
No. EERE-2016-BT-STD-0004, No. 58 Recommendation #7 at p. 6)
The CPWG concluded that when a circulator pump with manual speed
control is installed and set to maximum speed, it operates like a
single-speed pump and should receive the same weighting as a circulator
pump with no controls for the maximum speed weights, represented as
w<INF>i_max</INF> in equation (6). (Docket No. EERE-2016-BT-STD-0004,
No. 70 at pp. 183-184) For the weights associated with reduced speeds
using manual speed controls, the CPWG concluded that equal weighting of
0.3333 for each of the reduced speed points of 25, 50, and 75 percent
of BEP flow at maximum speed would best represent the ``average''
performance of the manual speed circulator pump at reduced speed,
represented as w<INF>i_reduced</INF> in equation (7). (Docket No. EERE-
2016-BT-STD-0004, No. 71 at pp. 433-437)
DOE requested comment on the CPWG-recommended test method and the
unique test points, weights, and speed factors for circulator pumps
distributed in commerce with manual speed controls. Specifically, DOE
requested comment on whether the technology or market for such controls
has changed sufficiently since the term sheet to warrant a different
approach. 86 FR 24516, 24525.
Grundfos recommended that DOE remove manual speed control from the
regulation, stating that these pumps should be tested as circulator
pumps with no control. (Grundfos, No. 113 at p. 4) Grundfos asserted
that these devices are not manually controlled in real application and
are simply set at a desired speed, violating the intention of energy
savings and the intention of the ability to reduce speed during
operation. (Grundfos, No. 113 at p. 3)
DOE notes that the CPWG specifically addressed the issues raised by
Grundfos in discussing how the test points at maximum speed were
designed to represent the performance at maximum speed and account for
operation at maximum speed the majority of the time, while the test
points at reduced speed allowed some ``credit'' for being able to
reduce speed. (Docket No. EERE-2016-BT-STD-0004, No. 70 at p. 201-202)
As stated previously, the CPWG concluded that about 75 percent of the
time, circulator pumps with manual speed controls are operated at
maximum speed, as reflected in its recommended procedure. (Docket No.
EERE-2016-BT-STD-0004, No. 71 at p. 377) For these reasons, DOE
proposes to include manual speed control as a test method in the
circulator pump test procedure.
HI recommended using the modified testing methodology in HI 41.5-
2021 section 41.5.3.4.5 for manual speed control. Specifically, HI
believes the minimum system control head should be the value at 25
percent BEP on the reference curve for the manual control (and pressure
control) method. HI described its findings that intersecting the pump
curve at BEP and requiring the control mode to be above the reference
curve was too limiting. HI asserted that this did not represent the
controls available in the market, nor did it properly demonstrate the
benefit of the onboard controls. HI commented that section 41.5.3.4.5
allows controls to be rated below the reference curve with power
correction back to the reference curve. (HI, No. 112 at 5) HI stated
that this change eliminates the need for all control curves to exist
above the reference curve, allowing for a better presentation of
control curves used in the market and for the circulator pump CEI
values to better represent a pump's capabilities. (HI, No. 112 at p. 2)
The Advocates supported the update in HI 41.5-2021 that includes a
modification to correct for test data below the reference curve,
stating that this improves representativeness for many circulator pump
models. (Advocates, No. 114 at pp. 1-2) As stated previously, NEEA
generally supported adopting HI 41.5-2021 as the test method for pumps,
which incorporates these modifications discussed by HI and the
Advocates. (NEEA, No. 115 at p. 4)
DOE tentatively determines the CPWG recommendations regarding the
test method for manual speed control circulator pumps are appropriate
and representative, as they account for the likelihood that a
circulator pump with manual speed controls will be installed and
operated at maximum speed, but also accounts for the potential energy
savings associated with reduced speed operation. However, DOE
understands that through stakeholders' experience with using this test
method, certain changes to the term sheet recommendations would improve
representativeness by capturing the benefit of onboard controls
available in the market. Therefore, DOE proposes to test circulator
pumps with manual speed controls consistent with the provisions in
section 41.5.3.4.5 of HI 41.5-2021, as follows: (1) The tested control
must produce head equal to or greater than 25 percent of BEP head at a
minimum of one test point (HI 41.5-2021 section 41.5.3.4.5 #2a), and
(2) the control curve setting being evaluated must achieve 100 percent
BEP flow of the reference curve (HI 41.5-2021 section 41.5.3.4.5 #2b).
DOE also proposes that the CER be calculated as the weighted average of
P<INF>in,max</INF> and P<INF>in,reduced</INF>, as shown in equations
(5), (6), and (7), but with removal of the requirements for test points
to be at or above the reference curve. DOE notes that HI 41.5-2021
section 41.5.3.4.5 #3 still retains that provision, which DOE assumes
to be an error based on HI's comments and recommendations in response
to the May 2020 RFI.

[[Page 72117]]

DOE also notes that the introductory text of HI 41.5-2021 section
41.5.3.4.5 specifies that the test method applies to manual speed
control, which can be operated without an external input signal, but
DOE also believes this provision is superfluous as manual speed
controls by definition do not require an external input signal.
DOE requests comment on the proposed test method and the unique
test points, weights, and speed factors for circulator pumps
distributed in commerce with manual speed controls.
6. External Input Signal Control
As discussed previously and as stated in the May 2021 RFI, the
final control variety considered by the CPWG was external input signal
controls. External input signal controls are controls in which the
device that responds to the stimulus, or the primary control logic, is
external to the circulator pump. Unlike pressure and temperature
controls, the logic that defines how the circulator pump operating
speed is selected in response to some measured variable (e.g.,
temperature, pressure, or boiler fire rate) is not part of the
circulator, as distributed in commerce. Instead, it is part of another
control system, such as a building management system or a boiler
control system. (Docket No. EERE-2016-BT-STD-0004, No. 72 at p. 84) 86
FR 24516, 24525.
For circulator pumps that have only an external input signal
control, the CPWG recommended testing along the reference control curve
to achieve the test point flow rates with a head at or above the
reference system curve with the same weights as temperature and
pressure controls, as shown in equation (4). The CPWG recommended that,
in order to ensure that the rating was representative of the
performance of such pumps, the external input signal control must be
the only control mode that can be used with the circulator pump, and
the circulator pump must not be able to operate without an external
input signal. (Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendations
#9 at pp. 7-8); 86 FR 24516, 24525.
The CPWG asserted that if external input signal control is one of
multiple options available on a circulator pump, or the pump is able to
operate without an external input signal, it is less likely that the
external input signal control option is going to be utilized since it
requires external logic and equipment in order to operate properly.
(Docket No. EERE-2016-BT-STD-0004, No. 72 at pp. 216-218, 229). The
CPWG recommended testing circulator pumps with external input signal
controls similar to manual speed controls. (Docket No. EERE-2016-BT-
STD-0004, No. 47 at p. 480) Specifically, the CPWG recommended testing
a circulator pump sold with external input signal controls and another
control variety with a simulated signal both: (1) Along the maximum
speed circulator pump curve to achieve the test point flow rates for
the max speed input power values and (2) with speed adjustment using a
simulated signal to the lowest speed setting that will achieve a head
at or above the reference curve at the test point flow rates for the
reduced speed input power values. (Docket No. EERE-2016-BT-STD-0004,
No. 58 Recommendation #9 at pp. 7-8); 86 FR 24516, 24525.
As such, the CPWG recommended that for circulator pumps distributed
in commerce with external input signal controls among other control
varieties, the PER<INF>CIRC</INF> should be calculated as the weighted
average of P<INF>in,max</INF> (the weighted average input power at
specific load points across the maximum speed curve) and
P<INF>in,reduced</INF> (the weighted average input power at specific
load points at reduced speed), similar to circulator pumps with manual
speed control, as shown in equation (8), (9), and (10):
[GRAPHIC] [TIFF OMITTED] TP20DE21.009

Where:

PER<INF>CIRC</INF> = circulator pump energy rating (hp);
Z<INF>max</INF> = speed factor weight of 0.30;
P<INF>in--max</INF> = weighted average input power at maximum
rotating speed of the circulator pump (hp);
Z<INF>reduced</INF> = weighted average input power at reduced
rotating speed of the circulator (hp).
[GRAPHIC] [TIFF OMITTED] TP20DE21.010

Where:

P<INF>in--max</INF> = weighted average input power at maximum speed
of the circulator (hp);
W<INF>i--max</INF> = 0.25;
P<INF>in.i--max</INF> = power input to the driver at maximum
rotating speed of the circulator pump at each test point i (hp);and
i = test point(s), defined as 25, 50, 75, and 100 percent of the
flow at BEP.
[GRAPHIC] [TIFF OMITTED] TP20DE21.011

[[Page 72118]]

Where:

P<INF>in--reduced</INF> = weighted average input power at reduced
speeds of the circulator pump (hp);
W<INF>i--reduced</INF> = 0.3333;
P<INF>in.i--reduced</INF> = power input to the driver at reduced
rotating speed of the circulator pump at each test point i (hp); and
i = test point(s), defined as 25, 50, 75 percent of the flow at BEP
of max speed and head values at or above the reference curve.
(Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendations #6B and #7
at pp. 5-6); 86 FR 24516, 24525-24526.

The CPWG recommended the speed factors of 0.30 at maximum speed and
0.70 at reduced speed in order to produce a rating on an equivalent
basis as that of a circulator pump with a typical differential pressure
control. (Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #7 at
p. 6). In addition, these speed factors would represent the likelihood
that a circulator pump with an external input signal control is
selected to operate with that external input signal control, and
whether the signal it receives results in the circulator pump reducing
speed. 86 FR 24516, 24526.
DOE requested comment on the CPWG-recommended test method for
circulator pumps distributed in commerce with only external input
signal controls, as well as for those distributed in commerce with
external input signal controls in addition to other control varieties.
Specifically, DOE requested comment on whether the technology or market
for such controls has changed sufficiently since the term sheet to
warrant a different approach. 86 FR 24516, 24526.
HI stated that it is not aware of any technical or market changes.
(HI, No. 112 at p. 5). As stated previously, Grundfos recommended that
external input and temperature controls be tested in the same way, with
labeling to differentiate these control methods for consumer purposes.
Grundfos stated that the functional characteristics are the same
between both methods. (Grundfos, No. 113 at p. 4) DOE addressed this
comment in section III.D.4.
DOE notes that the CPWG-recommended test method for circulator
pumps distributed in commerce with only external input signal controls
is generally consistent with that found in section 41.5.3.4.4 of HI
41.5-2021. HI 41.5-2021 contains additional specifications not found in
CPWG recommendations that, for circulator pumps with only external
input signal control, manual speed adjustment or simulated external
input signal can be used to achieve the relevant flow rates (section
41.5.3.4.4.1 #2). DOE also notes that the CPWG-recommended test method
for circulator pumps distributed in commerce with external input signal
controls in addition to other control varieties is mostly consistent
with that found in section 41.5.3.4.4.2 of HI 41.5-2021. However, where
the CPWG recommendations specify testing using a simulated signal,
whereas HI 41.5-2021 specifies testing using manual speed adjustment
(section 41.4.3.4.4.2 #2). In addition, HI 41.5-2021 does not specify
using the lowest speed setting that results in a head value at or above
the reference system curve; rather, it specifies to manually adjust the
speed to achieve the specified flow rates with head at or above the
reference control curve (section 41.4.3.4.4.2 #2).
DOE proposes to specify a test method for circulator pumps sold
only with external input signal control and that cannot operate without
an external input signal. Specifically, DOE proposes to test along the
reference system curve to achieve the test point flow rates with a head
at or above the reference curve, and that CEI would be calculated as
shown in equation (2). DOE also proposes to test circulator pumps sold
with external input signal controls along with other controls, or which
can be operated without an external input signal control, both: (1)
Along the maximum speed circulator pump curve to achieve the test point
flow rates for the max speed input power values and (2) with speed
adjustment that will achieve a head at or above the reference system
curve at the test point flow rates for the reduced speed input power
values. DOE proposes that in either case, either manual speed
adjustment or simulated external input signal can be used to achieve
the relevant flow rates. DOE is not proposing that the speed adjustment
include the ``lowest speed setting'' that results in a head value at or
above the reference system curve; however, DOE addresses this issue in
its enforcement provision proposals (section III.F.2). Finally, DOE
proposes that the CEI should be calculated as the weighted average of
P<INF>in,max</INF> and P<INF>in,reduced</INF>, as shown in equations
(8), (9), and (10).
Based on consideration of the CPWG recommendations and stakeholder
comments, DOE tentatively concludes that the proposed test provisions
for circulator pumps distributed in commerce with external input signal
controls would produce representative results for such equipment and
would not be unduly burdensome to conduct.
DOE requests comment on the proposed test method and the unique
test points, weights, and speed factors for circulator pumps
distributed in commerce with external input signal controls. In
particular, DOE requests comment on whether manual speed adjustment
and/or simulated external input signal are appropriate for testing
circulator pumps with external input signal only, as well as circulator
pumps with external input signal in addition to other control
varieties. DOE also seeks comment on whether it is necessary to
reference the ``lowest speed setting'' when determining the appropriate
test points. Finally, DOE seeks comment on whether the test points and
weights for circulator pumps distributed in commerce with external
input signal control in addition to other control varieties are
appropriately reflective of their energy consumption in the field
relative to other control varieties.
7. No Controls
As discussed previously and as stated in the May 2021 RFI, for
circulator pumps with no controls,\24\ the CPWG recommended testing the
pump along the maximum speed circulator pump curve to achieve the test
point flow rates of 25, 50, 75, and 100 percent of BEP flow. (Docket
No. EERE-2016-BT-STD-0004, No. 58 Recommendation #9 at p. 7); 86 FR
24516, 24526.
---------------------------------------------------------------------------

\24\ In this document, circulator pumps with no controls are
also inclusive of other potential control varieties that are not one
of the specifically identified control varieties.
---------------------------------------------------------------------------

The CPWG also recommended that for circulator pumps distributed in
commerce without manual speed controls, pressure controls, temperature
controls or external input signal controls, PER<INF>CIRC</INF> should
be calculated with the unique weights and test points as shown in
equation (11):

[[Page 72119]]

[GRAPHIC] [TIFF OMITTED] TP20DE21.012

Where:

PER<INF>CIRC</INF> = circulator pump energy rating (hp);
w<INF>i</INF> = 0.25;
P<INF>in,i</INF> = power input to the driver at each test point i
(hp); and
i = test point(s), defined as 25, 50, 75, and 100 percent of the
flow at BEP.
(Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #6A at pp.
4-5); 86 FR 24516, 24526.

The CPWG recommended the 0.25 weights at each test point (i.e., 25,
50, 75, and 100 percent of the flow at BEP) in order to account for the
variety of systems and operating points a single-speed circulator pump
may encounter. (Docket No. EERE-2016-BT-STD-0004, No. 70 at pp. 172-
173); 86 FR 24516, 24526.
DOE requested comment on the CPWG-recommended test methods, test
points, and weights for circulator pumps with no controls. 86 FR 24516,
24526.
HI stated that it is not aware of any changes; however, HI
recommended that DOE change the term ``no controls'' to ``full speed''
to ensure market clarity and align with common terminology. (HI, No.
112 at p. 5) Grundfos also recommended that DOE change this name to
Full Speed to clarify the intent of the testing and make it clear that
this test method is only to define the baseline circulator pump CEI and
is not a qualified control method for rating a circulator pump by
itself. (Grundfos, No. 113 at p. 4)
DOE notes that the CPWG recommended test method for circulator
pumps with no controls is consistent with that in section 41.5.3.4.1 of
HI 41.5-2021 (``Determination of CER--Full Speed''). In response to
Grundfos, DOE notes that the ``no controls'' test method as recommended
by the CPWG and as proposed in this NOPR is a test method for rating a
pump that does not have any of the other controls for which a test
method is specified. DOE proposes to define this test method separately
from the calculation to determine the CER<INF>STD</INF>. In response to
HI, DOE understands that as part of the HI Energy Rating program,
manufacturers are using the no controls test to determine the most
consumptive rating for their pumps. Therefore, in order to provide
regulatory clarity about which pumps must be rated using the ``no
controls'' test method, but also accommodate the option for any pump to
be rated using the ``no controls'' test method, DOE proposes to refer
to this test method in the regulatory text as the test method for
circulator pumps without external signal, manual, pressure, or
temperature controls (i.e., full speed test). DOE also proposes
additional language in the scope section regarding this clarification.
Consistent with the recommendations of the CPWG, DOE proposes to
test circulator pumps without external input signal, manual, pressure,
or temperature controls along the maximum speed circulator pump curve
to achieve the test point flow rates. DOE agrees that since these
circulator pumps with no controls are single-speed controls and only
have a single speed, testing at maximum speed is representative of the
typical operation of circulator pumps with no controls. Additionally,
DOE proposes to use equation (11) with the unique weights and test
points to test circulator pumps with no controls, with nomenclature
updated from PER<INF>CIRC</INF> to CER.
DOE requests comment on the proposed test method for circulator
pumps distributed in commerce with no controls.

E. Determination of Circulator Pump Performance

As stated in the May 2021 RFI, as part of the September 2016 CPWG
Recommendations, the CPWG recommended that all test points be tested on
a wire-to-water basis, in accordance with HI 40.6-2014, with minor
modifications. The CPWG also recommended that if an updated version of
HI 40.6 is published prior to publication of the test procedure final
rule, DOE should review and incorporate the updated version. (Docket
No. EERE-2016-BT-STD-0004, No. 58, Recommendation #10 at p. 8-9); 86 FR
24516, 24526. The CPWG also recommended several modifications related
to frequency of data collection, BEP speed, electrical measurement
equipment, relevant parameters at specific load points, power supply
characteristics, and rounding of values for calculating and reporting
purposes. (Docket No. EERE-2016-BT-STD-0004, No. 58 Recommendation #10
at pp. 8-9)
Two updated versions of HI 40.6--HI 40.6-2016 and HI 40.6-2021--
have been published since the CPWG meetings concluded. Section III.E.1
discusses HI 40.6-2021, the industry standard, which DOE proposes to
incorporate by reference, for measuring the performance of circulator
pumps, noting the changes made from the previous version of HI 40.6-
2014. DOE believes that it is necessary to make several exceptions,
modifications, and additions to this test procedure to ensure accuracy
and repeatability of test measurements (sections III.E.2.a through
III.E.2.c) and that the test method produces results that reflect
energy efficiency or energy use during a representative average use
cycle without being unduly burdensome to conduct. Additionally, DOE
proposes specific procedures for calculating the CEI and rounding of
values to ensure that the resultant ratings are determined in a
consistent manner (section III.E.2.d).
1. Incorporation by Reference of HI 40.6-2021
As stated in the May 2021 RFI, in 2016, HI published an updated
industry standard, HI 40.6-2016, ``Methods for Rotodynamic Pump
Efficiency Testing'' (``HI 40.6-2016''). 86 FR 24516, 24526. This
update aligned the definitions and procedures described in HI Standard
40.6 with the DOE test procedure for pumps published in the January
2016 TP final rule. Appendix A to subpart Y to 10 CFR part 431. In the
September 2020 Early Assessment RFI for pumps, DOE requested comment on
the potential effect of incorporating HI 40.6-2016 by reference as the
DOE test procedure for pumps. 85 FR 60734, 60737. Grundfos, NEEA, and
HI commented that HI expects to publish another standard update in 2021
and urged DOE to incorporate by reference HI 40.6-2021 rather than HI
40.6-2016 (Grundfos, Docket No. EERE-2020-BT-TP-0032, No. 07 at p. 2;
NEEA, Docket No. EERE-2020-BT-TP-0032, No. 08 at p. 6; HI, Docket No.
EERE-2020-BT-TP-0032, No. 06 at pp. 1, 3). HI specified that HI 40.6-
2016 included updates to match DOE's test procedure for pumps, and that
HI 40.6-2021 would further include editorial revisions and would add
circulator pump testing, and also would not impact measured values,
burden, or representativeness. (HI,

[[Page 72120]]

Docket No. EERE-2020-BT-TP-0032, No.06 at p. 3); 86 FR 24516, 24526. At
the time of the May 2021 RFI development, HI 40.6-2021 was not yet
published.
In the May 2021 RFI, DOE sought comment and feedback on whether HI
40.6-2016 or HI 40.6-2021 is an appropriate test method for conducting
wire-to-water testing of circulator pumps, as recommended by the CPWG.
In addition, DOE sought comment on whether the modifications in HI
40.6-2016 and/or HI 40.6-2021 adequately capture the CPWG recommended
modifications in Recommendation #10. 86 FR 24516, 24526.
HI stated that HI 40.6-2021 should be incorporated by reference and
that the 2021 edition modified the 2016 version only to add specific
testing requirements for circulator pumps. (HI, No. 112 at p. 5)
Grundfos also stated that DOE should accept HI 40.6-2021 for
incorporation into the regulation and that it provides appropriate
testing methods as defined by the CPWG. Grundfos also stated that there
were some specific deviations from Recommendation #10 with respect to
``Relevant Parameters at Specific Load Points.'' Specifically, Grundfos
stated that while implementing the industry rating program,
manufacturers identified that requiring all tested flow points to be
within <plus-minus>10 percent of the reference curve was not feasible
for pressure control, especially when operating at constant pressure at
heads below the BEP head. Grundfos further stated that the HI committee
made modifications to this recommendation in HI 41.5 that preserve the
integrity of the calculation of efficiency and allow for these products
to be properly tested and labeled. (Grundfos, No. 113 at p. 4-5)
NEEA, the Advocates, and the CA IOUs recommended that DOE adopt HI
41.5-2021 as the test method for circulator pumps. (NEEA, No. 115 at p.
4, Advocates, No. 114 at p. 1, CA IOUs, No. 116 at p. 2) The Advocates
stated that an update to the program guideline, HI 41.5-2021, includes
a modification to correct for test data below the reference curve and
that they understand that this change improves representativeness for
many circulator pump models and is consistent with the intent of the
term sheets. They also stated that HI 41.5-2021 includes additional
minor modifications to improve accuracy and clarity. (Advocates, No.
114 at pp. 1-2) Similarly, NEEA stated that HI 41.5-2021 includes
slight modifications from the original term sheet for testing with
pressure controls that operate below the reference curve, and that the
modifications provide more representative values. (NEEA, No. 115 at
p.4)
China made several requests related to specific provisions in the
HI 40.6 test procedure. China commented that DOE should present the
information related to pump test acceptance grades and corresponding
tolerance, referring to Table 8 of part 4.4.1 and the provision of part
4.4.2 in ISO 9906:2012. China recommended that DOE clarify the
scientific basis of the selection of the 7 test points which are 40,
60, 75, 90, 100 and 120 percent of the flow rate at the expected BEP.
China further recommended that DOE clarify the efficiency testing
method for integrated design products of electric pumps. (China, No.
111 at p. 3)
Since publication of the May 2021 RFI, HI has published HI 40.6-
2021. DOE has reviewed HI 40.6-2021 and determined that the test
methods contained within HI 40.6-2021 are generally consistent with HI
40.6-2014 and are sufficiently specific and reasonably designed to
produce test results to determine a CEI that is representative of an
average use cycle of applicable circulator pumps. Specifically, Table
40.6.2 of HI 40.6-2021, like HI 40.6-2014, defines and explains how to
calculate driver power input,\25\ volume per unit time,\26\ pump total
head,\27\ and other relevant quantities, which are essential to
determining the metric.
---------------------------------------------------------------------------

\25\ The term ``driver or control power input'' in HI 40.6-2021
is defined as ``the power input to the driver or control;'' in this
NOPR, DOE refers to ``driver power input'' as the power to either
the motor or the controls, if present.
\26\ The term ``volume per unit time'' in HI 40.6-2021 is
defined as ``. . . the volume rate of flow in any given section . .
. Also referred to as flow, flow rate, and rate of flow.''
\27\ The term ``pump total head'' is defined in HI 40.6-2021 as
``the algebraic difference between the outlet total head and the
inlet total head'' and is used synonymously with the term ``head''
in this document.
---------------------------------------------------------------------------

HI 40.6-2021 also contains appropriate specifications regarding the
scope of pumps covered by the test method, standard rating conditions,
equipment specifications, uncertainty calculations, and tolerances. The
electrical measurement specification and associated equipment
specifications in section C.4.3 of HI 40.6-2021 contain the relevant
measurement specifications for certain non-energy metrics (i.e., true
RMS current, true RMS voltage, and real power) that manufacturers may
choose to make representations about for each rated circulator pump.
These specifications also describe the relevant measurements used in
the calculation of true power factor (``PF'') at each applicable load
point for each circulator pump control variety, a non-energy metric
manufacturers may wish to use to make representations. In addition, HI
40.6-2021 contains a new appendix E with specific test instructions for
circulator pumps. DOE notes that section 41.5.3.1 of HI 41.5-2021
references Appendix E of HI 40.6-2021 as the test standard that governs
measurements of all test points in the standard. DOE has reviewed HI
40.6-2021 with respect to the minor modifications listed by the CPWG in
Recommendation #10. DOE has found that recommendations regarding
frequency of data collection are included in section 40.6.5.5.1, and
recommendations regarding electrical measurement equipment and power
supply characteristics are included in section C.3.4.1 and Table
40.6.3.2.3. The recommendation regarding BEP speed--specifically, to
test at max speed with no adjustment to nominal--is addressed in
Appendix E of HI 40.6-2021, which excludes sections 40.6.5.5.2,
40.6.6.1, and 40.6.6.1.1, dealing with the specified speed of rotation
and translation to that specified speed. The recommendations for
relevant parameters at specific load points have been addressed in
Appendix E of HI 40.6-2021 as well as HI 41.5-2021, with some
modifications. These provisions are discussed in section III.E.2.c of
this NOPR. The recommendations for rounding values for calculation and
reporting purposes are not addressed in HI 40.6-2021 or HI 41.5-2021;
DOE discusses these provisions in section III.E.2.d of this document.
In response to NEEA, the Advocates, and the CA IOUs, DOE does not
propose to incorporate by reference HI 41.5-2021 as the test method for
circulator pumps, as noted in section II. DOE instead proposes to rely
on the industry test standard, HI 40.6-2021, with additional provisions
in regulatory text consistent with HI 41.5-2021.
In response to China, with respect to section 40.6.4.4 of HI 40.6-
2021, DOE notes that HI 40.6-2021 provides methods to determine energy
efficiency as opposed to guaranteeing certain performance (e.g., pump
head, flow, power, or efficiency) in a particular application. As such,
acceptance grades are not relevant. However, HI 40.6-2021 does define
permissible fluctuations in Table 40.6.3.2.2. With respect to the test
points in 40.6.5.5.1, DOE discusses these further in section III.E.2.c
of this document.
With respect to section 40.6.3 of HI 40.6-2021 and the efficiency
testing method of integrated design products of

[[Page 72121]]

electric pumps, DOE is not clear what is meant by ``integrated design
products.'' However, section 40.6.4.4 of HI 40.6-2021 discusses
determination of pump overall efficiency of a motor pump unit or a
complete pump (i.e., bare pump, mechanical equipment, driver and drive
coupled together and treated as an integral unit). In addition,
Appendix E of HI 40.6-2021 specifies that for circulator pumps, all
power measurements must be measured inclusive of the driver, or driver
and controls when applicable, and refers to section 40.6.4.4.
After considering stakeholder comments, DOE proposes to incorporate
HI 40.6-2021, inclusive of Appendix E, for the purposes of testing
circulator pumps, including the minor modifications and additions
discussed previously. However, DOE also proposes to exclude certain
sections of HI 40.6-2021 that are not relevant to determining the CEI
of tested circulator pumps, as discussed in section III.E.2.a.
Additionally, there are specifications that the CPWG recommended for
the circulator pump test procedure that are not included in HI 40.6-
2021, including test arrangements for twin-head circulator pumps and
circulators-less-volute specific procedures for calculating the CEI and
rounding of values. DOE also discusses determination of driver power
input at specified load points, as included in HI 40.6-2021 and HI
41.5-2021, as compared to the CPWG recommendations. These modifications
and additions are discussed in sections III.E.2.b through III.E.2.d of
this document.
DOE requests comment on the proposal to incorporate by reference HI
40.6-2021, inclusive of Appendix E, into the proposed appendix D to
subpart Y, with the exceptions, modifications, and additions described
in section III.E.2 of this document.
2. Exceptions, Modifications and Additions to HI 40.6-2021
In general, DOE finds the test methods contained within HI 40.6-
2021 are sufficiently specific and reasonably designed to produce test
results to determine a CEI that is representative average use cycle of
applicable circulator pumps. However, only certain sections of HI 40.6-
2021 are applicable to the proposed circulator pump test procedure. In
addition, DOE proposes certain exceptions, modifications, and additions
to ensure test results are sufficiently repeatable and reproducible,
addressed in the subsequent sections III.E.2.a through III.E.2.d of
this document.
a. Applicability and Clarification of Certain Sections of HI 40.6-2021
Although DOE is incorporating by reference HI 40.6-2021 as the
basis for its test procedure, DOE notes that some sections of the
standard are not applicable to the circulator pump test procedure,
while other sections require additional specification regarding their
applicability when conducting the circulator pump test procedure.
DOE is not proposing to reference section 40.6.4.1, ``Vertically
suspended pumps,'' and section 40.6.4.2, ``Submersible pumps,'' of HI
40.6-2021 in the circulator pump test procedure because circulator
pumps are IL pumps and are not vertical turbine or submersible pumps.
As such, the test provisions applicable to vertical turbine and
submersible pumps described in section 40.6.4.1 and section 40.6.4.2 of
HI 40.6-2021 would not apply to the circulator pump test procedure.
Additionally, section 40.6.5.5.2 of HI 40.6-2021, ``Speed of
rotation during test,'' requires that the speed of rotation to
establish flow rate, pump total head, and power input be within the
range of 80 percent to 120 percent of the rated speed. However, in the
proposed circulated pump test procedure, rated or nominal speeds are
not relevant, as DOE is not proposing that speed be measured as part of
the test procedure. Similarly, section 40.6.6.1, ``Translation of test
results to the specified speed of rotation,'' describes the method by
which tested data can be translated to the rated speed of rotation for
subsequent calculations and reporting purposes. As DOE is not proposing
that speed be measured as part of this circulator pump test procedure,
translation of tested results based on speed is not necessary. As a
result, DOE is not proposing to reference sections 40.6.5.5.2 and
40.6.6.1 (including 40.6.6.1.1) of HI 40.6-2021. This is consistent
with the exclusions for circulator pump testing in Appendix E of HI
40.6-2021.
DOE also proposes to exclude section 40.6.5.3, ``Test report,''
that provides requirements regarding reporting of test results and
Appendix B, ``Reporting of test results,'' that refers to DOE's
existing reporting requirements at 10 CFR 429.59 for general pumps,
both of which are not required for testing and rating circulator pumps
in accordance with DOE's procedure. Specifically, the updated appendix
B references specific reporting requirements established in the general
pumps test procedure, of which not all specifications are applicable to
circulator pumps. DOE would propose specific certification and
reporting requirements for circulator pumps as part of an energy
conservation standard rulemaking, should such standards be
proposed.\28\
---------------------------------------------------------------------------

\28\ For more information on any energy conservation standard
rulemaking for circulator pumps see Docket No. EERE-2016-BT-STD-
0004.
---------------------------------------------------------------------------

Finally, DOE proposes to exclude Appendix G, ``DOE compared to HI
40.6 nomenclature,'' which refers to nomenclature used by DOE in the
general pumps test procedure (appendix A to subpart Y of 10 CFR part
431), and is not in all cases consistent with the terminology used in
the proposed circulator pump test procedure.
In summary, for the reasons stated previously, DOE is not proposing
to reference sections 40.6.4.1, 40.6.4.2, 40.6.5.3, 40.6.5.5.2,
40.6.6.1, 40.6.6.1.1, Appendix B, and Appendix G of HI 40.6-2021 as
part of the DOE test procedure for circulator pumps.
In addition, DOE notes that Appendix E of HI 40.6-2021 includes
modifications to testing in section 40.6.5.5.1 and 40.6.6.3, as
discussed in section III.E.2.c of this NOPR. DOE is proposing to
reference HI 40.6-2021 inclusive of Appendix E and the modifications
therein.
DOE requests comment on its proposal to not reference sections
40.6.4.1, 40.6.4.2, 40.6.5.3, 40.6.5.5.2, 40.6.6.1, 40.6.6.1.1,
Appendix B, and Appendix G of HI 40.6-2021 as part of the DOE test
procedure for circulator pumps.
b. Testing Twin Head Circulator Pumps and Circulators-Less-Volute
A twin head circulator pump is a type of circulator pump that
contains two impeller assemblies, mounted in two volutes that share a
single inlet and discharge in a common casing. HI 40.6-2014 does not
specify the procedures for testing twin head circulator pumps. In the
May 2021 RFI, DOE noted that the CPWG recommended that to test twin
head circulator pumps, one of the two impeller assemblies is to be
incorporated into an adequate, single impeller volute and casing. An
adequate, single impeller volute and casing means a volute and casing
for which any physical and functional characteristics that affect
energy consumption and energy efficiency are essentially identical to
their corresponding characteristics for a single impeller in the twin
head circulator pump volute and casing. (Docket No. EERE-2016-BT-STD-
0004, No. 58 Recommendation #11 at p. 9); 86 FR 24516, 24526-24527.
In the May 2021 RFI, DOE sought comment on whether the

[[Page 72122]]

recommendation for testing twin-head circulator pumps had been
adequately addressed in HI 40.6-2021. 86 FR 24516, 24527. HI stated
that in HI 41.5-2021, section 41.5.3 specifies the testing of twin head
pumps and refers to HI 40.6 as the testing standard to be used. HI also
noted that in section 41.5.1.5.1, the approach for testing twin head
circulator pumps aligns with Recommendation #11 from the CPWG. (HI, No.
112 at p. 5) Grundfos commented that HI 40.6 does not directly address
twin[hyphen]head or volute[hyphen]less products and that DOE would need
to specify the testing requirements for these product variants.
Grundfos further commented that HI 41.5.3 does identify how to test a
twin[hyphen]head circulator pump and is aligned with the current
twin[hyphen]head testing process that DOE established for IL products
in 10 CFR part 431 subpart Y. (Grundfos, No. 113 at p. 5)
DOE has reviewed the test specification for twin head circulator
pumps and proposes the test specifications recommended by the CPWG for
twin head circulator pumps, which is consistent with section 41.5.3 of
HI 41.5-2021 and with stakeholder comments. This proposed treatment of
twin head circulator pumps would be consistent with the treatment of
twin head pumps in the general pumps test procedure at appendix A to
subpart Y of part 431.
DOE requests comment on the proposed test procedure for twin head
circulator pumps.
As discussed in section III.B.4, a circulator-less-volute is a
circulator pump with a complete motor that is sold without a volute,
but for which a paired volute is available in commerce from a
manufacturer. HI 40.6-2014 did not specify procedures for testing
circulators-less-volute. As stated in the May 2021 RFI, the CPWG
recommended that to test circulators-less-volute, the circulator-less-
volute should be paired with the specific volute(s) with which the
circulator pump is advertised to be paired, based on manufacturer's
literature, to determine the CEI rating for each circulator-less-volute
and volute combination. (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendation #12 at p. 9); 86 FR 24516, 24527.
In the May 2021 RFI, DOE sought comment on whether the
recommendation for circulators-less-volute had been adequately
addressed in HI 40.6-2021. 86 FR 24516, 24527. Grundfos stated that HI
40.6 does not directly address volute-less products and that DOE would
need to define the testing requirements for this product variant. For
testing of circulating pumps without volutes, Grundfos stated that a
``reference volute'' can be used for testing purposes, in which the
manufacturer defines the volute to be used during testing, and that
this same process is used in the regulated EU market. (Grundfos, No.
113 at p. 1-2, 5) China stated that the test method of circulator-less-
volute pumps has not been specified and that DOE should define the test
method for these pumps. (China, No. 111 at p. 3)
DOE notes that HI 41.5-2021 does not address circulators-less-
volute. As such, DOE is proposing instructions for testing circulators-
less-volute. Specifically, consistent with CPWG recommendations and
Grundfos' comment, DOE proposes that the circulator-less-volute would
be paired with specific volute(s) with which the circulator-less-volute
is offered for sale or advertised to be paired with, and that the
combination would be subject to the proposed applicable DOE test
procedure for that circulator-less-volute model.
DOE recognizes that circulators-less-volute may be offered for sale
or advertised to be paired with multiple volutes, and that each
combination may have a different CEI. Since each of these volutes may
impact the CEI rating, each volute and circulator-less-volute pairing
would represent a unique pairing. Therefore, DOE proposes that the CEI
for each volute and circulator-less-volute pairing be determined
separately. In the context of other equipment, DOE provides that
manufacturers may elect to group similar individual models within the
same equipment class into the same basic model to reduce testing
burden, provided all representations regarding the energy use of
individual models within that basic model are identical and based on
the most consumptive unit. See 76 FR 12422, 12429 (Mar. 7, 2011). DOE
proposes to allow manufacturers of circulator pumps to group similar
volute and circulator-less-volute pairings within a given basic model
rating to minimize testing burden, while still ensuring that the CEI
rating is representative of minimum efficiency or maximum energy
consumption of the group. Circulator-less-volute manufacturers could
opt to make representations of the CEI of each individual circulator-
less-volute and volute combination, or could elect to make CEI
representations regarding a circulator-less-volute combined with
several individual volutes and rate the group with the same
representative CEI value, which would be representative of the least
efficient model.
DOE requests comment on the proposed test procedure for
circulators-less-volute. Specifically, DOE seeks comment as to any
additional details that should be addressed in testing a circulator-
less-volute with any given volute to determine applicable CEI values.
c. Determination of Circulator Pump Driver Power Input at Specified
Flow Rates
The CPWG recommended that for single speed circulator pumps, the
measured input power and flow data corresponding to the load points
from 60 percent of expected BEP flow to 120 percent of expected BEP
flow be linearly regressed and the input power at the specific load
points of 25, 50, 75, and 100 percent of BEP flow be determined from
that regression equation. (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendation #10 at p. 8) Appendix E of HI 40.6-2021 provides the
following testing modifications for circulator pumps, which differ from
the CPWG recommendations:
<bullet> Section 40.6.5.5.1 Test procedure--A minimum of nine test
points shall be taken for all performance tests. Points are to be
selected at approximately 10 percent, 25 percent, 40 percent, 60
percent, 75 percent, 90 percent, 100 percent, 110 percent, and 120
percent of the flow rate at the expected BEP of the circulator pump.
<bullet> Section 40.6.6.3 Performance curve--Determine the pump
total head versus flow rate curve only based on a polynomial of the 6th
order.
<bullet> Section 40.6.6.3 Performance curve--Determine the driver
power input at 25 percent, 50 percent, 75 percent, and 100 percent of
BEP based on a 3rd order polynomial curve of best fit of the tested
values (as specified in Section 40.6.5.5.1) at 10 percent, 25 percent,
40 percent, 60 percent, 75 percent, 90 percent, 100 percent, 110
percent, and 120 percent of expected BEP flow rate.
In response to the May 2021 RFI, China commented that the seven
test points (i.e., 40, 60, 75, 90, 100 and 120 percent of the flow rate
at the expected BEP of the pump) in section 40.6.5.5.1 are
approximately selected, and that these selected points are different
from those of PEI. China recommended that DOE clarify the basis of the
selection of these seven points. (China, No. 111 at p. 3)
DOE notes that Appendix E to HI 40.6-2021 has modified the
provision referenced by China. DOE has reviewed Appendix E and
determined that unlike general pumps, which require load points at 75,
100, 110, and 120 percent

[[Page 72123]]

of BEP flow, Appendix E requires determining the driver power input at
25, 50, 75, and 100 percent of BEP flow. If DOE were to define the
lowest test point as 40 percent, the lowest required drive power input
point (25 percent) would fall outside the range of tested points (i.e.,
40 percent to 120 percent). Whereas, if DOE were to define the lowest
test point as 10 percent, the lowest required drive power input point
(25 percent) would fall withing the range of tested points (i.e., 10
percent to 120 percent). DOE tentatively concludes that specifying a
test range, which is broader than the range for which driver power
input must be determined, through the use of a mathematical regression
would result in more accurate driver power input values than a test
range that is narrower than the range for which driver power input must
be determined. Therefore, DOE has preliminarily determined that it is
appropriate, consistent with Appendix E of HI 40.6-2021, to require
test points starting at 10 percent rather than a higher value such as
40 percent or 60 percent of expected BEP flow. Therefore, DOE proposes
to rely on the modified test points in Appendix E of HI 40.6-2021. DOE
notes that Appendix E also specifies curve fitting using specific
polynomial curves of best fit (6th order for head versus flow and 3rd
order for power versus flow). DOE has no reason to believe that these
curves are not appropriate, and as such, proposes to rely on the curve
fitting in Appendix E of HI 40.6-2021.
DOE requests comment on its proposal to adopt the provisions in
Appendix E of HI 40.6-2021 for determining circulator pump driver power
input at specified flow rates, including whether these provisions are
more appropriate than those recommended by the CPWG.
DOE notes that the procedure specified in section 40.6.6.3 and
Appendix E of HI 40.6-2021 is applicable for test points gathered at
maximum speed, but the other test points proposed for circulator pumps
with pressure controls, temperature controls, manual speed controls,
and external input signal controls are not specified in HI 40.6-2016.
For circulator pumps with pressure controls, temperature controls,
manual speed controls, and external input signal controls, the general
test procedure consists of ``sweeping'' the maximum speed curve (i.e.,
taking measurements at flow intervals along the head/flow curve
associated with maximum pump speed) to determine BEP, adjusting the
pump to the determined BEP at maximum speed, and then adjusting the
speed of the pump according to the applicable control or reference
system curve to achieve the specified load points at 25, 50, 75 percent
of BEP flow at reduced speed. As such, for these test points, unlike
the test points at maximum speed derived from the data collected to
determine BEP, manufacturers would adjust the operation of the pump to
specifically achieve the load points at 25, 50, 75, and 100 percent of
BEP flow, as applicable. Due to experimental uncertainty the specific
test points measured in the test protocol may not be exactly at 25, 50,
75, or 100 percent of the BEP flow load points specified in the test
procedure and, thus, the relevant power input measurements must be
adjusted to reflect the power input at the specific load points
specified in the test procedure. DOE notes that HI 40.6-2021 does not
specify the tolerances around which the specified flow values must be
achieved or how to adjust the test points to the specified load points,
accounting for such experimental tolerance.
The CPWG recommended that for circulator pumps with pressure
controls, manual speed controls, temperature controls, and external
input signal controls, all tested flow values must be within <plus-
minus>10 percent of the target flow load points as specified by the
reference system curve. In addition, the CPWG recommended that the
tested driver input power should be adjusted to the specified flow and
head points, except that any head values that are above the reference
system curve by more than 10 percent should not be adjusted. The CPWG
also clarified that, in their recommendation, if the tested head value
is below the reference curve by more than 10 percent, the circulator
pump must be retested. (Docket No. EERE-2016-BT-STD-0004, No. 58
Recommendation #10 at p. 8) While not specifically recommended, the
CPWG discussed adjusting the test points proportionally, consistent
with the method for adjusting reduced speed test points adopted in the
January 2016 TP final rule. See 81 FR 4086, 4155-4156 (Jan. 25, 2016);
(Docket No. EERE-2016-BT-STD-0004, No. 70 at pp. 325-328)
HI 41.5-2021 includes certain modifications to these provisions, as
noted by HI in their comments. Specifically, under HI 41.5-2021, all
tested flow values must be within <plus-minus>5 percent of the target
flow load points as specified by the reference system curve. (HI 41.5-
2021 section 41.5.3.4.2 #3c, 41.5.3.4.3, 41.5.3.4.4.1-2, 41.5.3.45) HI
stated that this change limits the pump efficiency ranges allowed for a
given test point and minimizes variation in CEI values for a given
test. In addition, any head values that are above the reference system
curve (including within 10 percent) are not adjusted. HI stated that
this change eliminates a discontinuity in CEI values when transitioning
between corrected and uncorrected values and allows for better
representation of pump CEI. Finally, for pressure control and manual
speed control, tested head is allowed to be below the reference curve
and corrected back to the reference curve. HI stated that this change
eliminates the need for all control curves to exist above the reference
curve allowing for a better representation of control curves used in
the market and for the circulator pump CEI values to better represent a
pump's capabilities. (HI, No. 112 at p.2) These provisions are found
throughout each of the individual control variety test methods in HI
41.5; a summary is available in 41.5.1. As stated previously, HI, NEEA,
the CA IOUs, and the Advocates supported use of HI 41.5-2021. (HI, No.
112 at p. 2; NEEA, No. 115 at p. 4, Advocates, No. 114 at p. 1, CA
IOUs, No. 116 at p. 2).
DOE interprets HI 41.5-2021's updated provision to reduce the
tested flow tolerance to <plus-minus>5 percent of the target flow load
points as an indication that this tolerance has been achievable in
tests.
DOE notes that HI's comment and the Introduction to HI 41.5-2021
(section 41.5.1) state that correction of power to the reference curve
above the reference curve has been removed. However, in section
41.5.3.4.2 (pressure speed control) and 41.5.3.4.5 (manual speed
control), the test method says ``Adjust measured driver input power to
the specific flow and head points as defined in [the reference curve],
except do not adjust for head values when head is at or above the
reference curve.'' This indicates that driver input power measured
above the reference curve should still be adjusted based on deviation
from the flow point. In addition, section 41.5.3.4.3 (temperature speed
control) and 41.5.3.4.4 (external input signal speed control) still
retain the provision not to adjust for head values that are above the
reference curve by more than 10 percent.
DOE proposes to incorporate the provisions in HI 41.5-2021, rather
than removing all correction of power measured above the reference
curve for all test methods. DOE believes that correction for flow
points within the tolerance is still appropriate. If stakeholders
comment that the test methods in HI 41.5-2021 have been implemented
incorrectly and that all correction of power above the reference

[[Page 72124]]

curve should be removed, and provide accompanying support, DOE will
consider adopting the provisions in HI 41.5-2021. DOE understands that
artificially adjusting head values significantly above the reference
system curve back to the reference system curve would result in an
unrepresentative CEI rating.
DOE notes that in the case that the tested head value is within 10
percent of the reference system curve, it is likely that the tested
circulator pump could achieve the specified flow and head values along
the reference system curve and that the deviation in head, in this
case, would likely be due to experimental uncertainty. DOE notes that
unlike pressure controls and manual speed controls, circulator pumps
with temperature controls and circulator pumps with external input
signal controls should be able to match the required speed to meet the
exact head values at each flow rate described by the reference system
curve. Therefore, DOE believes that continuing to adjust for head
values within 10 percent above the reference curve would not be likely
to cause any discontinuity in CEI for these control methods.
Regarding permitting testing below the reference curve for pressure
control and manual speed control, DOE proposes these changes to the
CPWG recommendations in sections III.D.3 and III.D.5 of this document.
DOE also agrees that given testing below the curve would be permitted,
the measured test points should be corrected back to the reference
curve, as included in HI 41.5-2021.
DOE notes that the proposed load points are specified with a
discrete flow value (i.e., 25, 50, 75, and/or 100 percent of BEP flow)
and, for temperature control and external input signal controls, a
minimum head value (i.e., at or above the reference system curve).
Therefore, as proposed the flow values must be achieved within <plus-
minus>5 percent and, for temperature controls and external input signal
controls, the tested head values must not be more than 10 percent below
the reference system curve. Any test point with a flow value that is
more than <plus-minus>5 percent away from the specified value or, for
temperature controls and external input signal controls, a head value
is more than 10 percent below the reference system curve would be
invalid and, therefore, must be retested.
DOE also proposes to adjust the tested driver input power values
for all relevant test points for circulator pumps with temperature and
external input signal controls using the methods adopted in the January
2016 TP final rule and discussed by the Circulator Pump Working Group.
Specifically, DOE proposes that if the tested flow values are within
<plus-minus>5 percent of the flow load point specified by the reference
system curve and the head values are within <plus-minus>10 percent of
the head load points specified by the reference system curve, the
tested driver input power values would be proportionally adjusted to
the specified flow and head points, as shown in equation (12):
[GRAPHIC] [TIFF OMITTED] TP20DE21.013

Where:

P<INF>R,i</INF> = the driver power input (hp);
H<INF>R,i</INF> = the specified head at load point i based on the
reference system curve (ft);
H<INF>T,j</INF> = the tested head at load point j (ft);
Q<INF>R,i</INF> = the specified flow rate at load point i based on
the reference system curve (gpm);
Q<INF>T,j</INF> = the tested flow rate at load point j (gpm); and
P<INF>T,j</INF> = the tested driver power input at load point j
(hp).

DOE also proposes that for pressure controls and manual speed
controls, if the tested flow values are within <plus-minus>5 percent of
the flow load point specified by the reference system curve and the
tested head values are below the head load points specified by the
reference system curve, the tested driver power input values would be
proportionally adjusted to the specified flow and heat points as shown
in equation (12).
Finally, DOE proposes, consistent with the recommendations of the
CPWG and the modifications in HI 41.5-2021, that for temperature
controls and external input signal controls, if the tested head values
are above the reference system curve by more than 10 percent, or for
pressure controls and manual speed controls, if the tested head values
are above the reference system curve at all, only the flow values would
be proportionally adjusted to the specified value, as shown in equation
(13):
[GRAPHIC] [TIFF OMITTED] TP20DE21.014

Where:
P<INF>R,i</INF> = the driver power input (hp);
Q<INF>R,i</INF> = the specified flow rate at load point i based on
the reference system curve (gpm);
Q<INF>T,j</INF> = the tested flow rate at load point j (gpm); and
P<INF>T,j</INF> = the tested driver power input at load point j
(hp).

With regards to the test points to which the tolerance and
adjustment methods are applicable, DOE notes that the CPWG recommended
that ``all'' test points for circulator pumps with pressure controls,
temperature controls, manual speed controls, or external input signal

[…truncated; see source link]

View on FederalRegister.gov →Plain-text source

Indexed from Federal Register on December 20, 2021.

This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.