Energy Conservation Program for Consumer Products: Test Procedures for Central Air Conditioners and Heat Pumps

Federal RegisterJan 22, 2001

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DEPARTMENT OF ENERGY

Office of Energy Efficiency and Renewable Energy

10 CFR Part 430

[Docket No. EE-RM/TP-97-440]

RIN 1904-AA46

Energy Conservation Program for Consumer Products: Test Procedures for Central Air Conditioners and Heat Pumps

AGENCY:

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

ACTION:

Proposed rule and public hearing.

SUMMARY:

The Department of Energy (DOE) is proposing changes to its regulations on test procedures for central air conditioners and heat pumps. Today's revision of the test procedure is not expected to alter the minimum energy conservation standards currently in effect. The revised test procedure is up-to-date, more complete and better organized than the current version. It should yield more accurate measurements of the energy efficiency of central air conditioners and heat pumps.

DATES:

Comments must be received on or before March 23, 2001. DOE is requesting a signed original, a computer disk (WordPerfect 8) and 10 copies of the written comments. The Department will also accept e-mailed comments but you must send a signed original. Oral views, data, and arguments may be presented at the public workshop (hearing) in Washington, DC, beginning at 9 a.m. on February 7, 2001.

The Department must receive requests to speak at the workshop and a copy of your statements no later than 4 p.m., January 9, 2001, and we request that you provide a computer diskette (WordPerfect 8) of each statement at that time. The DOE panel will read the statements in advance of the hearing and requests that speakers limit oral presentations to a summary. Attendees will have an opportunity to ask questions.

ADDRESSES:

Please submit written comments, and requests to speak at the public hearing to: Brenda Edwards-Jones, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Hearings and Dockets, Test Procedures for Central Air Conditioners Including Heat Pumps, Docket No. EE-RM-97-440, EE-41, Room 1J-018, Forrestal Building, 1000 Independence Avenue, SW., Washington, DC 20585-0121. You may send email to:

brenda.edwards-jones@ee.doe.gov.

The hearing will be at the U.S. Department of Energy, Forrestal Building, Room 1E-245, 1000 Independence Avenue, SW., Washington, DC. You can find more information concerning public participation in this rulemaking proceeding in section VI, “Public Comment,” of this notice.

You may read copies of the transcript of the public hearing and public comments at the Department of Energy Freedom of Information Reading Room, U.S. Department of Energy, Forrestal Building, Room 1E-190, 1000 Independence Avenue, SW., Washington, DC 20585, (202) 586-3142, between the hours of 9 a.m. and 4 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Michael G. Raymond, U.S. Department of Energy, Energy Efficiency and Renewable Energy, Mail Station EE-41, Forrestal Building, 1000 Independence Avenue, SW, Washington, DC 20585-0121, (202) 586-9611

Eugene Margolis, Esq., U.S. Department of Energy, Office of General Counsel, Mail Station GC-72, Forrestal Building, 1000 Independence Avenue, SW, Washington, DC 20585-0103, (202) 586-9526

SUPPLEMENTARY INFORMATION:

The proposed rule incorporates, by reference, seven test procedures published by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE), as follows:

• Standard 23-1993, “Methods of Testing for Rating Positive Displacement Refrigerant Compressors and Condensing Units.”

• Standard 37-1988, “Methods of Testing for Rating Unitary Air-Conditioning and Heat Pump Equipment.”

• Standard 41.1-1986 (Reaffirmed 1991), “Standard Method for Temperature Measurement.”

• Standard 41.2-1987 (Reaffirmed 1992), “Standard Method for Laboratory Airflow Measurement.”

• Standard 41.6-1994, “Standard Method for Measurement of Moist Air Properties.”

• Standard 41.9-1988, “A Standard Calorimeter Test Method for Flow Measurement of a Volatile Refrigerant.”

• Standard 116-1995, “Methods of Testing for Rating for Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps.”

One test procedure of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers/Air Moving and Conditioning Association, Inc. (ASHRAE/AMCA) is incorporated by reference:

• Standard 51-1999, “Laboratory Methods of Testing Fans for Rating.”

One test procedure of the Air-Conditioning and Refrigeration Institute (ARI) is incorporated by reference:

• Standard 210/240-1994, “Unitary Air-Conditioning and Air-Source Heat Pump Equipment.”

You can view copies of these standards at the Department of Energy's Freedom of Information Reading Room at the address stated above. You can also obtain copies of the ASHRAE, ASHRAE/AMCA and ARI Standards from the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc., 1971 Tullie Circle, NE, Atlanta, GA 30329, http://www.ashrae.org; and the Air-Conditioning and Refrigeration Institute, 4301 North Fairfax Drive, Suite 425, Arlington, VA 22203, http://www.ari.org, respectively.

I. Summary of Proposed Rule

II. Introduction

A. Authority

B. Background

1. Short and Long-term Plans

2. Background for Today's Proposed Rulemaking

III. Discussion of Comments

A. General

1. Non-ducted split system air conditioners and heat pumps

2. Small-duct, high-velocity systems

3. Non-defrost (limited-range) heat pumps

4. Heat pumps that incorporate a heat comfort controller

5. Other commercially-available equipment that should be covered in the test procedure

B. Definitions

1. Revise definition 1.20 “Demand-defrost control system”.

C. Testing Conditions

1. Section 2.2.4. Wet-bulb temperature requirements for air entering the indoor and outdoor coils.

2. Section 2.2.5. Additional refrigerant charging requirements

D. Testing Procedures

1. Section 3.1.4. Indoor air volume rates for a variable-speed, constant CFM blower.

2. Section 3.1.4.1. Cooling air volume rate.

3. Section 3.1.4.1.1. External static pressure.

4. Sections 3.2.3 and 3.5.3. Testing a two-capacity compressor system.

5. Section 3.3. Capacity adjustments for barometric effects

6. Sections 3.5.3 and 3.8.1. Cyclic degradation coefficients

E. Calculations of Seasonal Performance Descriptors

1. Sections 4.1.4 and 4.2.4. Variable-speed bin calculations

IV. Summary of Proposed Modifications to the DOE Air Conditioner and Heat Pump Test Procedure

A. Update and Add References for ASHRAE and ARI Standards

B. Air Volume Rates

C. Cyclic Testing

D. Fanless (coil-only) Units

E. Frost Accumulation Test

F. Test Tolerance Tables

G. Pretest Intervals

H. Multi-Capacity Systems

I. Triple-split Systems

J. Time-Adaptive Defrost Control Systems

K. Test Unit Installation

L. Test Apparatus and Measurement/Sampling Frequency

M. Different Compressor Speeds and Indoor Fan Capacities Between Cooling and Heating

N. Secondary Test Requirements

O. HSPF Calculations

V. Procedural Requirements

A. Review Under the National Environmental Policy Act of 1969

B. Regulatory Review

C. Regulatory Flexibility Review

D. “Takings” Assessment Review

E. Federalism Review

F. Paperwork Reduction Act Review

G. Review Under Unfunded Mandates Reform Act of 1995

H. Review Under Executive Order 12988, “Civil Justice Reform”

I. Review Under the Treasury and General Government Appropriations Act, 1999

J. Plain Language Review

VI. Public Comment Procedures

A. Written Comment Procedures

B. Issues for Public Comment

C. Public Workshop

1. Procedures for Submitting Requests to Speak

2. Conduct of Workshop

I. Summary of Proposed Rule

Today's proposed rule concerns the testing aspect for central air-conditioners and central air-conditioning heat pumps. The Department develops these procedures for manufacturers to test products to measure energy efficiency, energy use, or estimated annual operating cost of a product. It will interest manufacturers, but consumers of air conditioners will see no changes due to this revision, which brings the test procedure up-to-date, and makes it more complete and better organized. Nearly all the technical content is preserved and the use of U.S. customary (i.e., inch-pound) units is maintained. Air conditioners and heat pumps that presently meet the NAECA energy conservation standards will still meet these standards when rated using the revised test procedure.

II. Introduction

A. Authority

The Energy Policy and Conservation Act requires the Department of Energy to establish the Energy Conservation Program for Consumer Products. This program sets test procedures, energy consumption and efficiency labeling, and energy conservation standards for many household, consumer products.

The Act requires DOE to determine to what extent a proposed test procedure would change the energy efficiency or energy use of a product from the current test procedure. If we determine that a new test procedure would change the efficiency or use of a covered product, we will amend the standard. To determine the new energy conservation standard, we measure the energy efficiency or energy use of a representative sample of covered products that minimally comply with the existing standard. The average efficiency of these representative samples, tested using the amended test procedure, constitutes the amended standard. EPCA, Section 323(e)(2).

Public Law 94-163, as amended by the National Energy Conservation Policy Act, Public Law 95-619, the National Appliance Energy Conservation Act of 1987, Public Law 100-12, the National Appliance Energy Conservation Amendments of 1988, Public Law 100-357, and the Energy Policy Act of 1992, Public Law 102-486, Part B of Title III of Energy Policy and Conservation Act, as amended, is referred to in this proposed rule as “EPCA” or the “Act.” Part B of Title III is codified at 42 U.S.C. 6291-6309.

B. Background

1. Short and Long-Term Plans

This proposed DOE test procedure is the first step of a planned two-step revision process. The immediate goal is to promulgate a revised test procedure that is up-to-date, more complete and better organized. Nearly all the technical content is preserved and the use of U.S. customary (

i.e.,

inch-pound) units is maintained. One especially important goal of this first step is to have air conditioners and heat pumps that presently meet the NAECA energy conservation standards to still meet these standards when rated using the revised test procedure.

The second step in the planned revision process is to convert the DOE test procedure to using Systeme Internationale (SI) units while maximizing compatibility with pertinent standards of the International Organization for Standardization (ISO). The goal of this second step is a DOE metric test procedure which will also meet the requirements specified by ISO for determining capacities, EER(s) for a “moderate” climate, and COP's. For example, DOE plans to directly reference selected ISO indoor and outdoor test conditions. However, the DOE test procedure will impose additional requirements, not found in the ISO test standards, that allow determination of the seasonal performance factors SEER and HSPF. Presently, the pertinent ISO standards are either under revision or are being newly developed so we can not yet fully determine the extent of compatibility between the DOE and ISO testing and rating procedures. DOE, via NIST personnel, is participating in the development of the ISO test standards in an effort to minimize the differences. A proposed DOE metric test procedure will be available for industry review several months after the revision of ISO standards (5151 and 13253 or, possibly a combined standard) is completed.

This two-step test procedure revision will not delay the concurrent revision of the NAECA energy conservation standards, nor will standards revision be delayed because of the planned conversion of the test procedure to SI units. Until a DOE metric test procedure has been promulgated, you will make predictions of seasonal performance using the I-P version of the DOE test procedure,

i.e.,

this revision. This revised test procedure modifies tests for certain configurations, but is not expected to impact the performance measurements. In the coming years, when a DOE metric test procedure is progressing through the rulemaking process, DOE and stakeholders will review the best time line for implementing the metric test procedure and instituting compatible NAECA energy conservation standards. As far as possible, the metric test procedure will retain the current energy efficiency descriptors, SEER and HSPF.

2. Background for Today's Proposed Rulemaking

The first DOE test procedure covering central air conditioners and heat pumps was published in the

Federal Register

on December 27, 1979, and became effective January 17, 1980. 44 FR 76700. The test procedure was modified once, in March 1988. 53 FR 8304 (March 14, 1988). Revisions made in 1988 included expanding coverage to variable-speed air conditioners and heat pumps, addressing split-type non-ducted units, and modifying the method used for crediting heat pumps that provide a demand defrost capability.

Five waivers to the DOE test procedure covering central air conditioners and heat pumps have been granted since the 1988 final rulemaking. Waivers have been granted to two different brands of non-defrost heat pumps, to two brands of combined heat pump-water heating appliances, and for a line of burner-assisted heat pumps. Non-defrost heat pumps do not contain a defrost controller and are designed to shut the compressor off under operating

conditions where frost accumulation on the outdoor coil is likely. Combined appliances use an extra condensing coil to permit the unit to provide domestic water heating in addition to space conditioning. Burner-assisted heat pumps use a gas-fired burner in the outdoor coil while using electricity to power the refrigerant compressor.

In revising this test procedure, we considered whether actions could be taken to eliminate the continued need for any of the granted waivers. Today's proposed rule covers testing and calculation of HSPF for non-defrost, all-electric heat pumps, eliminating the first two of the five waivers discussed in the preceding paragraph. As the market for dual fuel heat pumps, including burner assisted heat pumps, and combined heat pump-water heating appliances grows, we will pursue the development of separate test procedures for these devices, which will eliminate the remaining three waivers.

We completed the first draft of this revised test procedure for central air conditioners and heat pumps in June 1996. The draft test procedure addressed equipment features presently not covered and improved upon the completeness and readability of the document. The June 1996 draft test procedure was distributed to members of the HVAC industry and academia for comment on the proposed changes.

Several parties provided comments on the June 1996 draft test procedures. We determined that more input on several issues would be beneficial, and DOE held a workshop on September 25, 1997. The workshop focused on five areas of concern. The first area was the identification of commercially-available equipment that is not adequately addressed in the existing test procedure. Examples include non-defrost heat pumps, heat pumps that incorporate a heat comfort controller, multi-split non-ducted heat pumps, two-capacity heat pumps that are sized to meet the space cooling load while operating at low capacity, small duct systems, and single-speed heat pumps having a variable-speed indoor fan that is modulated based on outdoor temperature. The second issue was the appropriate way to conduct steady-state and cyclic testing on units having a variable-speed, constant-air-volume-rate indoor blower. The third area of concern dealt with appropriate adjustments in order to credit a demand defrost capability and to account for the effect of barometric pressure. A group of items that pertained to specifics on lab testing procedures composed the fourth topic of discussion. Examples included how to best test packaged units having leakage, whether to limit manufacturer-specified special lab set-up requirements, recommended static pressure tap manifolding, and electrical energy measurement requirements. The fifth issue concerned the development of new defaults for the cyclic degradation coefficients, as an alternative to having to conduct tests to determine the coefficients.

A transcript of the discussions at the September 25 workshop is available for review in the DOE Freedom of Information Reading Room. The section below summarizes comments received throughout the revision process. During the workshop, several items were introduced but left unresolved. In many of these cases, ARI industry members indicated that they would offer more input and, where possible, a consensus response in the months following the workshop.

At the invitation of ARI, NIST participated in a meeting and teleconferences hosted by the ARI Unitary Small Equipment Engineering Committee in September and October of 1997 and February of 1998. For the meetings/teleconferences that followed the September 25, 1997 Workshop, discussions on DOE test procedure issues focused mainly on eleven issues, namely: (1) Small duct systems, (2) non-defrost systems, (3) multiple split heat pumps, (4) variable-speed, constant CFM blowers, (5) heat pumps that incorporate a heat comfort controller, (6) two capacity heat pumps that are sized to meet the design cooling load while operating at low speed, (7) definition for a demand defrost system, (8) effects of barometric pressure, (9) testing of packaged systems with internal leaks, (10) special laboratory setups, and (11) new default values for the cyclic degradation coefficients, C

(the measure of performance degradation from cycling losses). Written comments were received dated 24 November 1997 from ARI (ARI, No. 6) that addressed these particular areas. ARI formed a task group to provide additional input on three items: #4, #6, and #9. ARI also hoped to provide data and a strawman approach for addressing item #11. These last four items were discussed during a February 1998 teleconference but ARI provided no consensus by the end of February, the cutoff date imposed by DOE.

The 24 November 1997 written comments from ARI are included among the overall comment summary provided below. With regard to unresolved issues associated with ARI items #4, #6, and #9, we implemented changes based on the information gathered to date. Today's rulemaking proposes no changes for the C

defaults that may be used instead of conducting extra tests. DOE is willing to investigate and consider new C

defaults based on the hardware features of the air conditioner or heat pump. ARI and its members have thus far provided no test data nor made any recommendations concerning the hardware features (

e.g.,

type of expansion device, with or without a time delay relay on the indoor fan, type of compressor, off-cycle power consumption, refrigerant charge quantity, rated capacity, etc.) that should be included in a statistical analysis to identify the primary factors and the associated correlations.

A draft of this proposed test procedure was posted to the Office of Codes and Standards web site in October 1998. This document was revised during the summer of 1999 to comply with the President's Memorandum of June 1, 1998, “Plain Language in Government Writing.” Thereafter, some sections of the proposed test procedure were reorganized and amended in response to comments received during the DOE internal review process.

In the proposed central air conditioner and heat pump standards rule (65 FR 59590, October 5, 2000), the Department discussed issues associated with mandating thermostatic expansion valves, or TXVs, to help maintain equipment performance under improper charge or airflow. In the standards final rule, we decided not to adopt a TXV requirement, but considered pursuing modifications to this test procedure to encourage the use of TXVs. Such modifications will not be part of this rulemaking, but will be considered in a separate process. Related issues that may be discussed in the separate process include the alternate rating method for mixed systems. The alternate rating method is not a part of this revision, which concerns only appendix M to subpart B of 10 CFR part 430. The alternate rating method is discussed in 10 CFR § 430.24(m). In the last revision of this test procedure in 1988, the adoption of a standard rating procedure for untested combinations of split systems was proposed, but the Department decided not to include a standard rating procedure in the test procedure rule. Instead, the Department requested the National Bureau of Standards to develop a rating method available to any manufacturer to use in rating untested combinations. Manufacturers may use this method or any other after obtaining the Department's approval. It may again be time to discuss a standard mixed system rating method included in the test

procedure. These issues will be discussed in a workshop to be held in the spring of 2001.

III. Discussion of Comments

Following the September 1997 workshop, we received comments from the ARI Unitary Small Equipment Engineering Committee and individual ARI members, Proctor Engineering Group, and from the Florida Solar Energy Center. We grouped these comments into the following categories corresponding to sections of the test procedure: General, Definitions, Testing Conditions, and Testing Procedures. (ARI, No. 6, PEG, No. 3, FSEC, No. 7)

A. General

1. Non-ducted Split System Air Conditioners and Heat Pumps

Non-ducted units may use one or more indoor coils. When two or more indoor coils are used, they may operate in response to a single or multiple room thermostats. Standards of the International Organization for Standardization (ISO) differentiate non-ducted units as single or multiple room thermostat systems. We refer to equipment having one or more indoor coils all controlled by a single indoor thermostat as mini-split systems. We refer to equipment that uses two or more indoor thermostats to regulate the operation of two or more indoor coils as multi-split systems.

The current DOE test procedure does not differentiate between mini-split and multi-split systems. Both are tested and seasonal calculations are based on all indoor coils operating simultaneously. The zoning capability of multi-split units, though not operating some indoor coils, is not credited.

As part of its 1992 waiver petition, EnviroMaster International (EMI) sought “to test its three and four zone MC/MH series systems in the manner prescribed in the DOE test for two zone systems.” 57 FR 53736 (November 12, 1992). The modification noted in the Decision and Order was to change the wording of Section 3.1.7 to the following:

“Subsystems of multizone split-type ductless systems shall be tested as a single system. The system energy efficiency shall be based on the sum of the measured capacities of all of the zones in the system divided by the total input power used by the subsystems compressors, outdoor fans, indoor air handlers, and any additional power used by the system.”

ARI commented on this issue: “Our members do not believe any change is necessary to the test procedures to address multiple split heat pumps. We are unaware of any unfair treatment of this product in the industry by the current test methods.” (ARI, No. 6 at 1).

We propose no changes in today's test procedure. The option of testing each zone separately is possible. Such extra testing should provide a more complete description of the unit's capabilities. However, the benefits would have to be weighed against the considerable increase in the testing burden. The Department recommends tabling this issue until a multi-split manufacturer deems that a different and, most likely, more burdensome test approach is needed.

2. Small-duct, High-velocity Systems

Unico originally requested that DOE add a new class (or subclass) of central air conditioners and heat pumps that covered small-duct, high-velocity (SDHV) systems. Unico recommended changes to the test procedure that were coupled with DOE issuing separate NAECA standards for SDHV systems. The main test procedure changes were to impose higher minimum external static pressures and lower maximum air volume rates requirements on SDHV systems. Unico also provided a proposed definition for SDHV systems. (Unico, No. 5 at 2).

Unico noted how small duct systems differ from more conventional systems: external static is typically 1.5 inches of water, air volume rate is usually one-half of a conventional system, duct outlets into the room are typically two inches in diameter, and air velocity entering the room is in the 800 to 2000 feet per minute range. “We feel this product is different enough that it * * * should be considered for a different class. We have different classes for room air conditioners; we have different classes for packaged terminal units and ductless systems versus ducted systems.” (Unico, No. 2HH at 42). ARI commented: “ARI believes that no changes to the existing test procedure are necessary for these products. They are currently tested and rated in accordance with the existing procedure. Furthermore, ARI does not believe a different product class or category should be created for small-duct systems, since that would allow for a potentially separate efficiency standard. They should be held to the same minimum efficiency standards as conventional systems. There is concern that a separate product class could open a loophole in the regulations. Other products might be specifically designed to meet the criteria of the new class, with the only intention being that they would be subjected to a less stringent efficiency standard, while still used in applications for typical equipment.” (ARI, No. 6 at 1).

Unico later submitted an alternative proposal to DOE. In its alternative proposal, Unico plans to exercise the option of testing its line of SDHV units as coil-only units. In the Unico product line, the blower assembly is sold separately from the indoor coil assembly. The only change in the test procedure needed to implement this alternative approach is to relax the maximum pressure drop allowed when testing coil-only units. Presently, the test procedure states that the pressure drop across the indoor coil assembly must not exceed 0.30 inches of water. Unico requested that the limit be increased, preferably to 0.50 inches of water.

Today's proposed test procedure sets a higher pressure drop limit of 0.5 inches of water when testing coil-only units that meet the definition of a small-duct, high-velocity system. The proposed definition is given in section 1.46. We welcome comments on this action. Possible points for consideration include whether the action is acceptable as proposed or if incorporated in combination with a different default fan power and heat adjustment.

3. Non-defrost (Limited-range) Heat Pumps

We granted the first of two waivers for non-defrost heat pumps to Airlex in 1988. 53 FR 52216 (December 27, 1988). The waiver called for testing at 47 °F and 62 °F in lieu of testing at 35 °F and 17 °F. HSPF was calculated. Airlex, to the knowledge of DOE, has since gone out of business. We granted the second waiver to EMI in November 1992. 57 FR 53736 (November 12, 1992). Unlike Airlex, EMI did not seek to report HSPF and so did not offer proposed modifications to the DOE test procedure. We required that EMI state in its printed materials on its non-defrost products that “no HSPF value has been measured since the heat pump cannot be operated at temperatures below 35 °F.”

At this time, non-defrost heat pumps appear to be limited to non-ducted, multi-zone, multi-split heat pumps having multiple refrigeration systems where one refrigeration system may be heating while another is cooling. In such systems, having one refrigeration system conduct a defrost while the other refrigeration system(s) is cooling is apparently quite difficult (see below EMI comment). No opposition was voiced at the workshop to a DOE proposal to cover non-defrost heat pumps in the test procedure. We also

received the following comments at the workshop:

In response to the question on why EMI can not make its non-ducted, multi-refrigeration system, multi-split heat pumps defrost, EMI stated “we have put preliminary designs together, but we've never been able to successfully control the defrost cycle while operating all the circuits.” (EMI, No. 2HH at 23). Trane spoke against the option of creating a new class and a new NAECA HSPF energy standard for non-defrost heat pumps. (Trane, No. 2HH at 24). An ARI representative said that presently a multi-zone multi-split would be tested with all refrigeration systems operating in the same mode. (ARI, No. 2HH at 23). In written comments received following the workshop, ARI stated: “For the same rationale as with small duct systems, ARI does not believe a separate product class or category is needed for non-defrost heat pumps. We also recommend no change in the current test procedure to accommodate non-defrost systems. As discussed above, they should be held to the same minimum efficiency standards as conventional systems.” (ARI, No. 6 at 1).

Since the workshop, DOE received information on non-ducted, multi-refrigeration system, multi-split heat pumps made by two manufacturers other than EMI. Both of these competing multi-split products provide a defrost capability. The key differentiating feature is that these units do not provide the option of simultaneous heating and cooling like the EMI product. EMI apparently values this simultaneous cooling/heating capability more than a defrost capability while these other two manufacturers do without the simultaneous mode feature in return for being able to defrost. To date, we have found no product that provides both the simultaneous heating/cooling feature and a reverse defrost cycle capability.

From a test procedure standpoint, several options are available. One option, in line with ARI's comment, is to make no applicable changes to the test procedure and allow the existing EMI (and Airlex) waivers to remain. This option defers the issue until we receive another waiver request for a non-defrost heat pump. A second option is to make additions to the test procedure so that the HSPF of any type of non-defrost heat pump could be evaluated. A third option is to exclude heat pumps that are designed to simultaneously heat and cool “whether they can defrost or not” from the scope of the test procedure. The rationale for exclusion would be that such units generally compete with commercial applications where packaged terminal heat pumps and air conditioners are used and so should be tested and rated in a manner comparable to the approach used for packaged terminal equipment (

i.e.,

heating performance descriptor becomes COP at 47 °F and the equipment has no HSPF rating). For this third option, the test procedure could either be changed to cover all other non-defrost heat pumps (even though DOE knows of only the EMI simultaneously heat and cool, non-defrost heat pump) or no changes could be made, again deferring until we receive another waiver petition.

DOE requests comment on the above three and any other options for handling non-defrost heat pumps. To provide an understanding of the test procedure changes required to cover non-defrost heat pumps, we include in today's proposed test procedure (see Sections 3.6.1.1 and 4.2.1.1) the steps required to test and rate most conceivable types of single-speed, non-defrost heat pumps.

4. Heat Pumps That Incorporate a Heat Comfort Controller

Heat comfort controllers modulate the operation of the resistive elements of a heat pump to minimize temperature swings of the heated supply air when operating below the heat pump's balance point. Frequently, they seek to maintain a minimum delivery temperature when operating above the balance point. This latter application can cause the system to use more electrical energy than the heat pump alone would use to meet the building load.

At the 25 September 1997 DOE workshop, the issue was discussed at some length. The workshop members noted that the item can be both an OEM product that is an integral part of the as-shipped heat pump or it can be a field added accessory that is provided by the heat pump manufacturer or, more commonly, by a third party supplier. Also, assuming that the test procedure was modified to cover heat pumps with a heat comfort controller, no workshop invitee spoke in favor of new and separate NAECA standards for such products. The following points were also made at the workshop:

ARI stated if the manufacturer incorporates a heat comfort controller as an OEM feature, it should be covered by the test procedure. (ARI, No. 2HH at 31). Trane stated if the test procedure is modified to cover heat comfort controllers, the rating should be based on operating the controller at its maximum delivery temperature. (Trane, No. 2HH at 60). Proctor Engineering commented: “Units designed to operate with strip heat above the balance temperature should not receive any special consideration in the test process or the [NAECA] Standard. Allowing special consideration will open the door to lower efficiencies in the field where installation errors already result in excessive strip heat use.” (PEG, No. 3 at 3). ARI commented: “We request DOE to develop a rating procedure for heat pumps that incorporate the use of electric resistance heat above the balance point. The procedure should be based on the highest indoor air delivery/supply temperature setting that the control system allows, so that the most conservative rating will be derived. Any heat pump that uses this feature, and still meets the minimum HSPF standard should be permitted. However, the existing ICC Model Energy Code prohibits such systems, because there is no rating method for them.” (ARI, No. 6 at 2).

Today's proposed test procedure covers heat comfort controllers as applied to most types of single-speed heat pumps. With the heat comfort controller disabled, conduct all the same heating mode tests. Following the normally conducted heating mode test at 47 °F outdoor temperature, conduct an extra abbreviated test with the controller enabled to determine the air delivery temperature when the controller is set to its maximum setting (see Section 3.1.9). We describe proposed steps for calculating the HSPF of a single-speed heat pump having a heat comfort controller in Section 4.2.1.2.

5. Other Commercially-available Equipment that Should Be Covered in the Test Procedure

One focus of the 25 September 1997 DOE workshop was to identify commercially-available equipment that is not covered by the DOE test procedure. For the majority of equipment discussed at the workshop, we provide separate discussions elsewhere in this summary. Equipment types that were discussed and thought not to be a commercial product included: (1) Triple-capacity heat pumps and (2) units that use a two-capacity (two-stage) compressor and a variable-speed indoor fan that is modulated at each fixed stage of compressor operation.

B. Definitions

1. Revise Definition 1.20 “Demand-defrost Control System”

ARI commented: “We recommend that DOE expand the current ARI Standard 210/240 definition of a demand defrost system to include sampling intervals of a minimum of 10 minutes and not to have the definition pertain to time adaptive systems.” (ARI, No. 6 at 2)

DOE's goal is to improve upon the existing definition provided in ARI Standard 210/240-94, Section A1.11, and in particular, to stop allowance of

the (maximum) 3 percent HSPF credit to units that truly do not offer a demand defrost capability. We provide a proposed definition for a “demand-defrost control system” that seeks to be consistent with ARI's comment as Definition 1.20.

C. Testing Conditions

1. Section 2.2.4. Wet-bulb Temperature Requirements for Air Entering the Indoor and Outdoor Coils

ARI commented: “In order to provide better repeatability when testing packaged systems, which may be susceptible to internal air leakage, ARI believes it may be necessary to specify an outdoor dew point temperature when units are located in the outdoor chamber (ambient). A task group has been formed to investigate this issue and we will provide our recommendations to DOE as soon as they are available.” (ARI, No. 6 at 2).

DOE's understanding of the impact of a leak that could result in optimistic results is as follows:

(1) Leak of outdoor air to a location upstream of the indoor coil but downstream of the test facility inlet wet bulb temperature (dew point, relative humidity) sensor. If the outdoor dew point is lower than the indoor dew point, the measured latent capacity will be higher than the true latent capacity, while the measured sensible capacity will be lower than the actual sensible capacity. The effect on total capacity will depend on dry bulb temperature of the outdoor air (82 °F or 95 °F) and the depression of the outdoor dew point relative to the indoor dew point.

(2) Leak of outdoor air to a location downstream of the indoor coil. Results are the same as (1) except that the depression of the outdoor dew point would have to be greater to overcome the negative effect on sensible capacity. The measured air volume rate on the indoor side would be higher than the actual rate at the coil and would thus increase the perceived sensible and latent capacity.

DOE's understanding of the other factors that are related to this issue are as follows. First, psychometric rooms have difficulty achieving and maintaining outdoor wet bulb temperatures in the mid 70's °F and higher during the A and B Tests. If the internal leakage is significant, obtaining a 6 percent energy balance would be difficult to achieve. Although potentially frustrating for a third party tester, the lack of an energy balance should provide impetus for the manufacturer to reduce the leakage. You can avoid the difficulty in maintaining the outdoor wet bulb temperature during the C and D dry coil tests by meeting the requirements of achieving a dry indoor coil, and by using the equation for determining sensible cooling capacity, as opposed to total cooling capacity.

In an effort to avoid potential cases where the leakage causes an optimistic result while still providing an energy balance of 6 percent or less, DOE recommends operating at an outdoor dew point temperature that is the same as the indoor dew point temperature during wet-coil tests where the unit does not reject condensate to the outdoor coil. DOE proposes a test tolerance of ±3.0 °F in the agreement of the average outdoor dew point temperature with the average indoor dew point temperature. In nominal terms, the target outdoor wet bulb temperatures will be 71.7 °F and 67.7 °F for the A and B Tests, respectively.

During heating mode tests, leaks could cause problems if the Outdoor Air Enthalpy Method is used to provide a secondary check of capacity. The proposed test procedure includes a recommendation for regulating the indoor side wet bulb temperature in an effort to minimize the difference between the indoor and outdoor-side dew point temperatures.

2. Section 2.2.5. Additional Refrigerant Charging Requirements

ARI stated: “We believe the test procedure, as currently written, reasonably addresses the issue of special laboratory setups when conducting tests, as prescribed in manufacturer's installation instructions. Therefore, we do not recommend any change with respect to this issue.” (ARI, No. 6 at 3).

Presently, any installation step is acceptable so long as it is specified in the manufacturer's installation instructions, including remarks that only apply if conducting laboratory testing. As discussed at the 25 September 1997 DOE workshop, the difficult issue is where to draw the line. Some special setups are justified and/or required when lab testing. DOE is only excluding special lab set-ups for refrigerant charging. With assistance from ARI and third-party laboratories, DOE will monitor test setup requirements to determine if manufacturers are specifying installation instructions inconsistent with the majority of lab installations or otherwise contrary to field practices. Furthermore, DOE is seeking assistance in establishing installation guidelines for items such as pre-washing of coils (

e.g.,

what cleaning agent to use, basic steps that specify the extent of the cleaning), run-in times on compressors, conditions where components (

e.g.,

crankcase heaters) are or are not electrically connected, exclusion of lab-only (or 25 feet only) lineset specifications, etc. These guidelines will be incorporated into future revisions of the test procedure to assist in obtaining consistency in the testing.

In today's proposed test procedure, the title of Section 2.2.5 changes from “Exclusion of special setup requirements if stated in the manufacturer published installation manual” to “Additional refrigerant charging requirements.” The section is included for two reasons. The first is to disallow the specification of two refrigerant charging criteria, one that applies for lab testing and one that applies for a field installation. The fact that a lab setting provides better quality control is not sufficient for permitting lab testing using a different charging criteria. The second reason for today's Section 2.2.5 is to avoid discrepancies and delays when third party testing is conducted. The third party testing facility should not have to consult with the manufacturer as to how the unit is to be charged. In the case of a certification failure, the issue of whether the testing facility charged the unit correctly should only be based on whether the manufacturer's charging criteria, as specified in the unit's installation instructions, were followed.

D. Testing Procedures

1. Section 3.1.4. Indoor Air Volume Rates for a Variable-Speed, Constant CFM Blower

ARI stated: “ARI is aware of the need to consider more explicit procedures for testing units with variable speed blowers. Therefore, we have organized a task group to develop a prescribed test method for testing units with variable speed blowers, and we will pass our recommendations on to DOE as soon as they are available.” (ARI, No. 6 at 1)

Today's proposed test procedure contains several changes from the existing test procedure to address testing of units having a variable-speed, constant CFM blower. For all tests, the exhaust fan of the air flow measuring apparatus is regulated to obtain an external static pressure that is as close to, while not being less than, the minimum external static pressure specified in the test procedure (see 3.1.4.1.1(b), 3.1.4.4.1, 3.1.4.4.2 and 3.1.4.4.3(b)). (The air flow measuring apparatus, by comparison, is not regulated to obtain the specified air volume rate, as is done when testing units having other than a constant-air-

volume-rate indoor fan.) For some units, one or more tests may have to be conducted at an external static pressure that is higher than the required minimum value because of instability problems encountered when trying to reduce the external static pressure to the specified minimum. In such cases, steps are outlined for correcting the test results if the difference between the as-tested and the specified minimum external static pressure is 0.03 inches of water or more. An example of the proposed correction method is provided in the last paragraph of Sections 3.3 and 3.7. For systems that operate at multiple air volume rates, the fan laws are used to approximate the target external static pressure for tests conducted at other than the air volume rate used during the A

and/or H1

test.

The proposed test procedure includes a check of the agreement between the lab-measured and manufacturer-certified air volume rates. Today's proposed test procedure calls for the two values to agree within 8 percent (see 3.1.4.1.1(b), 3.1.4.2, 3.1.4.4.2, and 3.1.4.4.3(b)). This percentage is proposed based on manufacturer's comments on the variability of the variable-speed motors relative to estimates of the impact on rated performance caused by an 8 percent deviation. Using the heat pump computer modeling program HPSIM, DOE finds that an 8 percent deviation in SCFM is expected to have a negligible impact on both capacity and EER at the B Test condition while still keeping the maximum impact on capacity at the A Test condition in the 2 percent range. DOE asks that manufacturers provide feedback on the proposed 8 percent tolerance as well as findings from lab testing and computer modeling on the impact on capacity and EER of airflow changes in the 5 to 10 percent range.

Cyclic tests on units having a constant CFM blower may be conducted with or without the indoor fan enabled. If the cyclic test is conducted with the blower disabled, steps for correcting for the power draw of the blower are specified (see 3.5 and 3.5.1).

2. Section 3.1.4.1. Cooling Air Volume Rate

This issue is of interest to the ISO working group that is revising its air conditioner and heat pump test standards. The adoption of a maximum air flow limit has thus far been opposed by the majority of the ISO working group member countries. The following comments were made at the DOE workshop. A Trane representative noted that the 37.5 SCFM per 1000 Btu/h (450 SCFM per ton) maximum air flow requirement is long-standing and is of value because it (1) sets a de facto maximum sensible heat ratio and (2) keeps the air flow in a range that avoids water being blown off the wetted evaporator. (Trane, No. 2HH at 193). A representative of York International suggested reevaluating the basis for the 37.5 SCFM per 1000 Btu/h maximum while considering both full load and part load capacity conditions. (York, No. 2HH at 197).

For today's proposed revision, no change is made in the maximum air volume rate limit. DOE sees such a limit as providing a hedge against promoting efficiency gain at the expense of compromised latent capacity, especially for coil-only units. The limit also helps in having the A and B Tests conducted with a fully wetted coil that, in turn, makes the capacity fluctuations less and the collection of 30 minutes of steady-state data more readily obtainable. DOE encourages and would participate in investigations on whether this limit should be other than its present value of 37.5 SCFM per 1000 Btu/h, or whether an alternative mechanism, such as a limit on sensible heat ratio, should be considered.

Discussion of this issue is timely because no such maximum air volume limit is presently included in ISO Standards 13253 and 5151 for ducted and non-ducted air conditioners and heat pumps. A U.S. proposal to adopt the metric-equivalent of the 37.5 SCFM per 1000 Btu/h limit was voted down by the ISO working group that is presently revising ISO Standards 5151 and 13253. The vast majority of other member countries on the working group perceive air volume rate as a design parameter that should not be impacted by a rating standard. The ISO standards provide capacity test conditions that correspond to a hot, dry climate where latent capacity is not a concern. ISO also provides capacity test conditions for a cool climate. ISO working group members from countries that will rate at this cool climate condition argue that high air volume rates are needed in order to assure that the air delivery temperature is not objectionably cool. Finally, with the exception of the U.S., most countries represented on the ISO working group are predominantly concerned with non-ducted products and calorimeter testing where indoor air volume rate is not typically measured.

The goal when converting the DOE test procedure to a metric format is to make it ISO compatible. Most ducted units sold in the U.S. today are rated at an air volume rate that is less than the 37.5 SCFM per 1000 Btu/h upper limit. This fact suggests that maximum efficiency is achieved at air volume rates lower than 37.5 SCFM per 1000 Btu/h. Thus, having a upper limit may not be important enough to warrant a deviation from ISO. Either way, now is the time to discuss this issue since the revision of the ISO Standard 13253 is still underway. However, it seems unlikely that ISO will adopt an upper limit on air volume rate.

3. Section 3.1.4.1.1. External Static Pressure

Proctor Engineering Group recommended the following changes to make the test specification conform better to measurements of installed systems. When testing units having an indoor fan, “the minimum static pressure should be revised to:

• 0.50 inches of water column for all systems, or

• The maximum allowable external static pressure specified by the manufacturer, whichever is less.”

When rating fanless units, “the default Btu/hr (watt draw of the indoor fan motor) should be revised to 2000 Btu/hr per 1000 cfm (586 Watts per 1000 cfm).” For comparison, the external static pressure and fan heat/power defaults presently used in the existing DOE test procedure are 0.1, 0.15, and 0.2 inches of water, with the assigned value being a function of the unit's rated capacity. The presently referenced fan heat/power default adjustment is 1250 Btu/h per 1000 SCFM (365 Watts per 1000 SCFM). Proctor Engineering Group supported its proposed changes by providing results from field measurements on 28 new systems in new construction in Phoenix, Arizona. (PEG, No. 3 at 3).

The Florida Solar Energy Center sent a report on field monitoring work which indicated that “the standard assumption of an external static pressure of 0.2 inches of water column (IWC) for the air handler fan was far lower than the typical values encountered in the field. The average we measured in 14 evaluated installations was 0.54 IWC (range was 0.27 to 0.91 IWC).” The commenter goes on to state his strong belief that “the ARI test condition should be modified to 0.5 IWC to better reflect the actual performance that will be achieved by the air conditioners operating under realistic conditions. Because of this change, the watt draw of the fan motor (and heat released into the supply air stream) should also be revised to reflect the increase in fan power from this change.” (FSEC, No. 7 at 1)

Because of concern that such changes would impact the SEER and HSPF of units that have ratings at or near the

NAECA minimum standard levels, DOE does not plan to change the static pressure requirements in this revision of the test procedure. Instead, DOE will continue dialogue with the working group that is revising ISO Standard 13253. When the revision of ISO 13253 is completed, DOE will determine the suitability of incorporating part or all of this test procedure in the DOE metric test procedure. ISO Standard 13253 is presently under revision with the present draft containing the following requirements for the minimum external static requirements. (The Inch-Pound equivalent values are not part of the proposed 13253 table but are included here to aid the reader.)

Minimum static pressures

Standard capacity ratings

(kW) [kBtu/h]

Minimum external static

pressure (Pa) [inches of H

0 to <8 [0 to <27.3]

25 [0.10]

8 to <12 [27.3 to <41.0]

37 [0.15]

12 to <20 [41.0 to <68.3]

50 [0.20]

20 to <30 [68.3 to <102.4]

62 [0.25]

30 to <45 [102.4 to <153.6]

75 [0.30]

45 to <82 [153.6 to <279.9]

100 [0.40]

82 to <117 [279.9 to <399.3]

125 [0.50]

117 to <147 [399.3 to <501.7]

150 [0.60]

[Above 147 Above 501.7]

175 [0.70]

The numbers up to 20 kW are consistent with the values presently cited in the existing and in this proposed revision of the DOE test procedure.

As for fanless units, the draft revision of ISO 13253 contains a thermodynamically-based equation (volume flow rate x total pressure drop divided by fan static efficiency x fan motor efficiency) to estimate default fan heat/power adjustments. Total pressure drop is taken as the sum of the following:

(1) The lab-measured pressure drop across the indoor, fanless unit

(2) The applicable minimum external static pressure listed in the above table

(3) An estimate for the pressure drop across a typical blower cabinet (=50 Pa).

The minimum external static pressure requirements thus impact both the rating for fanless and blower coil units. For residential size equipment, ISO Standard 13253R uses the following empirical fits to determine the fan static (

) and fan motor efficiencies (

MEr

=0.1881*

(

+ 50) − 0.4700

MEr

=0.060*

Ln[Q*(P

+ 50) /

]+0.123

Where

is the measured air volume rate of standard air (m

/s),

is the minimum external static pressure (Pa), and

is the internal static pressure drop of the indoor coil cabinet assembly measured during the cooling capacity test (Pa).

Any proposal to raise the minimum external static pressure requirements and possibly tweak the ISO approach for estimating fan heat/power adjustments will first have to be agreed upon by the U.S. delegates on the ISO working group. If the proposal is endorsed by the U.S. delegation, then the delegation must submit the proposed change for the consideration of the full working group. NIST, as a member of the U.S. delegation, has raised the issue for discussion among the U.S. delegation. At this point, the U.S. delegation does not have plans for recommending changes to ISO 13253 in this area.

4. Sections 3.2.3 and 3.6.3. Testing a Two-capacity Compressor System

ARI stated: “ARI agrees with DOE that the test procedure should be modified to accommodate more appropriate testing of multiple capacity heat pumps that are sized to meet the cooling load at fan speeds lower than the maximum. We have established a task group to investigate this issue, and will provide our recommendations to DOE as soon as they are available.” (ARI, No. 6 at 2).

The proposed test procedure covers two-capacity heat pumps that are designed to operate exclusively at low capacity in meeting the space cooling load while using both low and high capacities when space heating. SEER of the unit is evaluated in the same way as specified for a single-speed air conditioner. HSPF is evaluated using the same algorithm as specified for a “normal” two-capacity heat pump except that the building loads for the heating temperature bins are based on the heat pump's heating capacity when tested at

low capacity

and 47 °F outdoor dry bulb temperature. Previously, the building loads were tied to the heat pump's heating capacity at 47 °F and

high

compressor capacity. The change will drive the balance point of the heat pump down. The issue on this particular subject is whether the heat pump must have a lockout feature to prevent cooling at high capacity or is it sufficient that the rating is applicable so long as the heat pump is sized to operate at low capacity at design cooling conditions? The advantages of the lockout would be to (better) assure that high compressor capacity would not be used when cooling and a particular unit would only have one unique NAECA-required SEER and HSPF rating. Without the lockout feature, the unit would have two SEER and HSPF ratings. A lockout feature is required in accordance with today's proposed test procedure but DOE welcomes further discussion on this issue.

5. Section 3.3. Capacity Adjustments for Barometric Effects

ARI commented: “ARI is aware that barometric pressure can have an affect on test results. However, we believe DOE should allow ASHRAE to finish its analysis of this issue before making changes to the test procedure. The test procedure should be revised to reference ASHRAE Standard 37-1988, with the exception of the section that pertains to corrections made to capacities based on measured barometric pressures, since it is known this section contains an error and is being revised.” (ARI, No. 6 at 2).

Today's proposed test procedure reflects the recommendation made by ARI.

6. Sections 3.5.3 and 3.8.1. Cyclic Degradation Coefficients

In the existing DOE test procedure, the default values provided for cooling and heating cyclic degradation coefficients,

and

, are both 0.25. On the cooling side, the two optional tests are conducted on the majority of units because the experimentally-determined

is lower than 0.25. NIST, DOE and ARI members have discussed developing new defaults. The goal is to obtain more representative defaults resulting in less

testing

while still crediting features that enhance cyclic performance. The manufacturers and ARI, as part of their certification program, have experimentally determined the

of many units. DOE believes the available data could be used to evaluate a set of new defaults that depend on the hardware components of the air conditioner or heat pump. The compiling of the data, however, is a formidable and thus far uncompleted task.

ARI originally commented: “ARI endorses the concept of providing alternate degradation coefficients (

) for systems using specific components known to reduce the typical 0.25 default value. This could significantly reduce test burden by decreasing the need for the cumbersome cyclic test. ARI will continue to work with NIST on this effort, and provide whatever data our members authorize, to help determine appropriate alternatives.” (ARI, No. 6 at 3). More recently, ARI members have reconsidered the merits of seeking new

defaults. A final decision from ARI is pending.

DOE encourages ARI to provide data and recommendations needed to begin the investigation into better

defaults. If better

defaults are identified, DOE will initiate steps to implement defaults that are lower than the existing values of 0.25. Such lower defaults could only positively impact the SEER and HSPF of a unit and so would not require adjustments to the existing NAECA energy conservation standards. Defaults that are higher than the existing 0.25 values, which could only negatively impact SEER and HSPF, would most likely become effective the same time as new NAECA energy conservation standards. We will not delay efforts to move today's proposed rulemaking into a final rulemaking by the pursuit of better

defaults. If we identify better defaults in sufficient time before the issue of the final rule, so we can obtain public comments on the proposed

values, then we will incorporate the better defaults into the final rulemaking. If better defaults are identified after the final rulemaking, DOE will initiate a new rulemaking process where changes and comments are limited to the issue of new

defaults.

E. Calculations of Seasonal Performance Descriptors

1. Sections 4.1.4 and 4.2.4. Variable-speed Bin Calculations

In the existing DOE air conditioner and heat pump test procedure, a quadratic fit is used to approximate the change in EER and COP as a function of the outdoor bin temperature. Prior to the 25 September 1997 DOE workshop, consideration had been given to using an alternative fit, a linear over linear rational function of the form Y=(

)/(1+

). The rationale function was considered because it maintains a monotonic shape in all cases whereas a quadratic fit can have an inflection point between the points that it is fitting. For the purposes of interpolating the EER or COP of a variable-speed, all-electric heat pump or air conditioner, both fits are expected to give comparable results because the points being fitted have historically been close to linear. For the one variable-speed heat pump considered by NIST, for example, the two fits resulted in SEER and HSPF changes of 0.06% and 0.14%, respectively.

At the 25 September 1997 DOE workshop, the issue was discussed. Trane spoke against adopting the rational function on the basis that no practical problems had arisen with using the quadratic fit over the approximately 15 years that it has been used. (Trane, No. 2HH at 149-150).

Today's proposed test procedure maintains the use of the quadratic fit.

IV. Summary of Proposed Modifications to the DOE Air Conditioner and Heat Pump Test Procedure

In addition to the modifications cited in Section III, the proposed test procedure also incorporates the following changes.

A. Update and Add References for ASHRAE and ARI Standards

The existing test procedure references ASHRAE Standards 37-78 and 41.1 (no year) and ARI Standards 210-79, 240-77, and 320-76. The proposed revised version references ARI Standard 210/240-94 and ASHRAE Standards 23-93, 37-88, 41.1-86 (RA 91), 41.2-87 (RA 92), 41.6-94, 41.9-88, 51-99, and 116-95.

B. Air Volume Rates

ARI Standard 240-77 was previously referenced. Now, rather than referencing ARI Standard 210/240-94, we have added sections within this proposed test procedure. The main reason for no longer referencing ARI Standard 210/240 is that it does not cover variable-speed, constant CFM blowers and does not directly address two-capacity and variable-speed systems. It is preferable to have the overall issue of air volume rates covered in one place rather than in two. The main objective is to agree on air flow rate specifications. If ARI Standard 210/240 is revised to cover these systems, DOE may again reference the ARI Standard.

ASHRAE Standard 37-78 (or 37-88) is no longer referenced for the equation calculating the air volume rate of standard air. The factor 1+

is missing from the denominator of the equation given in Standard 37-88. This change has been adopted by the committee working to revise Standard 37.

Today's proposed test procedure adopts the approach used in the ISO Standard 5151 of conducting each test at zero external static pressure when testing a non-ducted unit.

C. Cyclic Testing

Industry practice and the method described in ASHRAE Standard 116 was adopted. Section 5.1 of the current Appendix M implies that the air volume rate is to be measured during cyclic tests. Standard test laboratory practice is to try to obtain the same velocity pressure or nozzle static pressure drop that was obtained during the comparable steady-state test. The air volume rate used in the cyclic test calculations is assumed to be the same air volume rate measured during the comparable steady-state test. This change is reflected in this proposed test procedure.

Concerning split-type non-ducted (ductless) systems, Section 4.1.1.5 of Appendix M states that “The integration time for capacity and power shall be from compressor cut-on time to indoor fan cutoff time.” The indoor fan is operated for 3 minutes prior to compressor cut-on and for 3 minutes after compressor cutoff during the final OFF/ON interval. This proposed test procedure adopts industry practice and integrates power from compressor OFF to compressor OFF and subtracts the electrical energy associated with operating the indoor fan during the initial 3-minute fan-only period. Space cooling capacity is integrated from compressor ON to indoor fan OFF. As with the present test procedure, fan energy for the three minutes after compressor cutoff is added to the integrated cooling capacity.

The present test procedure does not contain specific information regarding the air dampers: where to install them, how well they should seal, and how quickly they should respond. Much of this information is given in Appendix B of ARI Standard 210/240-94. Needed information is incorporated within the text of the proposed test procedure rather than making specific references to each pertinent section of Appendix B of the ARI Standard.

For dry coil tests, the proposed test procedure adopts ARI Standard 210/

240-94 Appendix B language with regard to the requirement that the drain pan be plugged and that the pan should be completely dry.

This notice of proposed rulemaking clarifies that the requirement of making electrical energy measurements using an instrument having an accuracy of ±0.5 percent of reading applies during both the ON and OFF intervals of cyclic tests.

Existing Section 4.1.3.1, which reads “The indoor and outdoor average dry-bulb temperature for the cyclic dry coil test D shall both be within 1.0 °F of the indoor and outdoor average dry bulb temperature for the steady-state dry coil test C, respectively,” has been removed from the proposed test procedure. This requirement is automatically met given the 0.5 °F test condition tolerance associated with each test.

For units having a variable-speed indoor fan, the manufacturer will have the option of conducting the cyclic tests with the indoor fan enabled or disabled, the latter being the default option if an attempt at testing with the fan enabled is unsuccessful. Specifically, if testing with the indoor fan operating and it automatically reverses, shuts down, or operates at an uncharacteristically high external static pressure, then a pull-thru method, where the fan is disabled, must be used. Although allowing the option of testing with the fan disabled is needed because of the potential fighting between the unit's fan and the exhaust fan of the air flow measuring apparatus, DOE seeks data from cyclic tests where the fan operates versus tests where the fan is disabled and the pull-thru method is used.

Although a unit having a variable-speed indoor fan may be designed to ramp its fan speed when cycling on and/or off, a step response in air volume rate is nonetheless required during cyclic tests. The work associated with moving the additional air during the ramp periods is performed by the exhaust fan of the air flow measuring apparatus. The step response begins at the initiation of ramp up and ends at the termination of ramp down. The rationale for imposing the step change is mainly due to the difficulty in obtaining the ramp response and then making an accurate measurement of the space conditioning delivered. Systems having indoor fans that ramp are expected to have low cyclic degradation coefficients (

) regardless of whether the ramp feature is used, thus the absolute improvement in

is expected to be minor. Still, the proposed method of testing will benefit these units. DOE has only been able to obtain data from one unit where two different ramp profiles were compared to the results from imposing step responses in air flow. In one case

went from 0.05 (“truth”: ramp) to 0.02 (approximation: step change) while in the second case the values were 0.025 and 0.00. DOE seeks additional data showing the difference between the ramp and step responses during cyclic tests.

D. Fanless (Coil-only) Units

Section 4.1 of the existing Appendix M calls for corrections to capacity and power based on CFM. Section 4.2 of existing Appendix M calls for corrections to capacity and power based on SCFM. ITS uses SCFM in all cases. Thus, the proposed test procedure adopts the practice of only specifying the corrections in terms of SCFM.

The proposed test procedure also adopts the ARI Standard 210/240-94 Appendix B requirement that a specific enclosure be constructed (1 inch ductboard) when testing a coil only unit that does not employ an enclosure.

E. Frost Accumulation Test

The proposed test procedure adopts the ASHRAE Standard 116-95 and ARI 210/240-94 convention of specifying the outdoor wet bulb temperature (33 °F) in place of the presently specified dew point temperature (30 °F).

F. Test Tolerance Tables

The current Appendix M contains tables covering all tests except steady-state cooling mode tests, for which Table III in ASHRAE Standard 37-78 is referenced. Table III of ASHRAE Standard 37-78 has been added to the proposed test procedure since all the other tables are included in Appendix M.

The test tolerance tables have been improved. For example, although a test condition tolerance for external resistance to air flow is provided in the current test procedure, it is not applicable for ducted units. Such a test condition tolerance is, however, now applicable to non-ducted units. Also, a test condition tolerance has been added for electrical supply voltage (previously, only a test operating tolerance was specified). Because ASHRAE Standard 37-78 does not cover cooling mode dry coil tests, a test condition tolerance on the indoor inlet wet bulb temperature is not applicable. Test tolerances given on the outdoor outlet dry and wet bulb temperatures are now noted as only being applicable when the Outdoor Air Enthalpy Method is used to provide the secondary capacity measurement.

For the Frost Accumulation Test, the intervals considered to be heating versus defrosting have been modified slightly. Specifically, in the existing test procedure in Section 4.2.3.3, the first 5 minutes after a defrost termination was included in the defrost interval. In the proposed test procedure, the time interval has been increased to 10 minutes. Also, in making the test condition conversion of 30° F dew point to 33° F wet bulb, the test operating tolerance and test condition tolerance convert to wet bulb temperature tolerances of 0.6° F and 0.3° F, respectively. This 0.6° F test operating tolerance on outdoor wet bulb temperature is more stringent than the value allowed for the steady-state tests. The 0.3° F test condition tolerance is the same as required for steady-state tests. Given that these tolerances should be less stringent that those required of a steady-state test, the proposed test procedure adopts the values given in ASHRAE Standard 37: 1.5° F and 0.5° F.

G. Pretest Intervals

Statements given in the DOE proposed test procedure regarding operation prior to recording data have been modified. These changes are as follows.

1. Wet Coil Tests

Existing: “The test room reconditioning apparatus and the equipment under test shall be operated until equilibrium conditions are attained” (Section 4.1.1.1).

Proposed: “For the pretest interval, operate the test room reconditioning apparatus and the unit to be tested until maintaining equilibrium conditions for at least 30 minutes at the specified Section 3.2 test conditions” (Section 3.3).

2. Dry Coil Steady-State Test

Existing: “The test room reconditioning apparatus and the equipment under test shall be operated until equilibrium conditions are attained, but not for less than one hour before data for test C are recorded” (Section 4.1.1.2).

Proposed: Same as proposed for Section 3.3 wet coil tests with the additional requirement to “ * * * operate the unit at least one hour after achieving dry coil conditions” (Section 3.4).

3. Dry Coil Cyclic Test

Existing: “ * * * test unit shall be manually cycled ‘off ’ and ‘on’ * * * until steadily repeating ambient conditions are again achieved in both the indoor and outdoor test chambers, but for not less than two complete ‘off/on’ cycles” (Section 4.1.1.2).

Proposed: “After completing a minimum of two complete compressor

OFF/ON cycles, determine the overall cooling delivered and total electrical energy consumption during any subsequent data collection interval where the test tolerances given in Table 8 are satisfied” (Section 3.5).

4. Maximum and High Temperature Heating Mode Tests

Existing: “The test room apparatus and test units must be operated for at least one hour with at least one-half hour at equilibrium and at the specified test conditions prior to starting the test” (Section 4.2.1.1).

Proposed: “For the pretest interval, operate the test room reconditioning apparatus and the heat pump until equilibrium conditions are maintained for at least 30 minutes at the specified Section 3.6 test conditions” (Section 3.7).

5. Heating Mode Cyclic Test

Existing: “ * * * and be cycled ‘on’ and ‘off’ as specified in 3.2.1.2 until steadily repeating ambient conditions are achieved for both the indoor and outdoor test chambers, but for not less than two complete ‘off’/‘on’ cycles” (Section 4.2.1.2).

Proposed:

Same as for the dry coil cooling mode cyclic test (see above).

6. Frost Accumulation Test

Existing: “The test room reconditioning equipment and the unit under test shall be operated for at least one-half hour prior to the start of a ‘preliminary’ test period” (Section 4.2.1.3).

Proposed: “Operate the test room reconditioning apparatus and the heat pump for at least 30 minutes at the specified Section 3.6 test conditions before starting the ‘preliminary’ test period” (Section 3.9).

7. Low Temperature Test

Existing: “The test room reconditioning equipment shall first be operated in a steady-state manner for at least one-half hour at equilibrium and at the specified test conditions. The unit shall then undergo a defrost, either automatic or manually induced” (Section 4.2.1.4).

Proposed: Same as for the Maximum and High Temperature Heating mode tests (see above) with the following additions. “After satisfying the Section 3.7 requirements for the pretest interval, but before you begin collecting data to determine Q

(17) and E

(17), conduct a defrost cycle. This defrost cycle may be manually or automatically initiated. (Section 3.10).

H. Multi-Capacity Systems

1. Two-Capacity Heat Pumps that Lock Out Low Capacity at Higher Outdoor Temperatures.

The existing test procedure covers two-capacity units that operate exclusively at high capacity when the building load exceeds the unit's low capacity. The Department is unaware of any two-capacity units that implement such a control strategy and so coverage of them is excluded from today's proposed test procedure. However, coverage was added to address units that lock out low capacity operation at low (heating) or high (cooling) outdoor temperatures. For this new case, a step was added which reverts to a single capacity calculation. The proposed test procedure uses the C

determined based on cycling at low capacity (or the 0.25 default) in all cases. The Department welcomes comments on any control strategy used by two-capacity units that are not adequately covered in today's proposed test procedure.

2. Systems Having a Single-Speed Compressor and a Variable-Speed Indoor Fan Where Fan Speed or Air Volume Rate Depends on Outdoor Temperature.

The proposed test procedure requires two extra steady-state tests for the cooling mode (see Table 4) and two extra steady-state tests for the heating mode (see Table 10). An extra Frost Accumulation test is optional.

3. Specification of the Air Volume Rate for Tests at Low Capacity

In the existing test procedure, the air volume rate to be used when testing a two capacity system while operating at low capacity is not explicitly addressed. The proposed test procedure requires the use of the fan laws, as is now done for variable-speed systems, to determine the air volume rate when testing a unit having an indoor fan. For fanless units, the air volume rate used when conducting tests at low capacity (i.e., the Minimum Air Volume Rate) is the higher of

(1) The rate specified by the manufacturer; or

(2) 75 percent of the air volume rate used for the high capacity tests.

DOE believes that a lower limit is needed given the finite capabilities of the typical multi-speed furnace blower that is used in field installations. The 75 percent minimum is based on very limited data collected by NIST. The subject has been discussed by industry members at such forums as ASHRAE meetings but no formal consensus has yet been reached for the specified percentage. Data and comments are requested, especially with regard to the specified value of the lower limit.

I. Triple-split Systems

The DOE test procedure refers to ASHRAE Standard 37 on the issue of equipment installation and test set up procedures. ASHRAE Standard 37, in turn, states that you must use the calorimeter air-enthalpy method arrangement when testing units where the compressor is in the indoor section and separately ventilated. For this arrangement, an enclosure must be built around the equipment under test within the indoor chamber. The present requirement is burdensome and DOE knows of no one who uses it when testing triple-splits. Furthermore, the heat loss from the indoor compressor section should be reflected in an adjusted output capacity and not by a raised entering air temperature. The amount of heat dissipated to the ambient by the indoor compressor section of such units is usually minimized as a result of the enclosure of the third section being insulated (mainly in an effort to reduce the operating noise). Based on limited information gained to date, the amount of heat lost from the indoor compressor section is on the order of 2 percent or less of the unit's space conditioning capacity.

The proposed test procedure instructs that triple-split systems are not to be tested using the calorimeter air-enthalpy method arrangement (see note in Section 2.6). At this juncture, no algorithm or method for assigning/determining the heat loss from the indoor compressor section is included. If triple-split systems become more popular and if information becomes available indicating the heat loss from the indoor compressor section exceeds 2 percent of the total, air-side capacity, then DOE will revisit the option of having a capacity adjustment.

J. Time-Adaptive Defrost Control Systems

When conducting a Frost Accumulation test on a heat pump having a time-adaptive defrost control system, repeatable frosting and defrosting intervals typically require (if obtainable at all) an excessive number of cycles. Until a better alternative is identified, defrosts initiated during the “preliminary” test and the “official” test will be manually induced. The manufacturer will be required to provide information as to how long the unit would optimally frost before initiating a defrost. The manufacturer will have to provide information on

how to induce a defrost cycle at the appropriate elapsed time. The controls of the unit, however, will still control the duration of the defrost cycle, once initiated.

K. Test Unit Installation

For the most part, equipment installation requirements will continue to be performed according to the manufacturer's installation instructions. However, the proposed test procedure adopts the lab and field practice of insulating the low pressure line(s) of a split system. Also, Section 2.2.5 restricts the use of special refrigerant charging criteria for lab testing.

L. Test Apparatus and Measurement/Sampling Frequency

1. Inlet Plenum for Blower Coils

In the current DOE test procedure, no inlet plenum is required when testing blower coil units. The proposed test procedure recommends that an inlet plenum be installed if space permits. (Lab ceiling height on vertical installation is a limitation.) The test procedure recommends using an inlet plenum that is constructed according to the design specified for fanless units. See Section 2.4.2.

2. Manifolded Static Pressure Taps

The triple-T configuration was found in 1976 to be the preferred method for manifolding static pressure taps (“The design of piezometer rings” by K. A. Blake, Journal of Fluid Mechanics, Vol. 78, part 2, pp. 415-428). The triple-T configuration and the more widely used complete ring, four-to-one manifolding configuration are presently part of the draft revision of ASHRAE Standard 37. This revised test procedure recommends use of either of these two manifolding methods, which are shown in Figure 1. The broken ring, four-to-one manifolding configuration may be used but is not recommended.

3. Temperature Measurement Intervals

The proposed test procedure specifies that dry-bulb temperature measurements are to be measured at the intervals specified in ASHRAE Standard 41.1-86 (RA91). Wet bulb temperature, dew point temperature, or relative humidity are to be measured at the minimum sampling interval specified in Definition 1.14.

4. Temperature Measurement Accuracies

The proposed test procedure defers entirely to ASHRAE Standard 41.1-86 (RA 91) for accuracy and precision requirements.

5. Grid of Individual Temperature Sensors Within the Indoor-Side Outlet Plenum

The proposed test procedure adopts the ARI Standard 210/240-94 Appendix B requirements that a temperature spread of 1.5 °F or less be obtained, and that the outlet temperature grid be composed of a minimum of 9 sensors (while recommending 16). Also, the proposed test procedure recommends redundant sensors to determine the change in dry bulb temperature across the indoor coil.

6. Duct Loss Correction

The proposed test procedure adds a correction for the heat transfer between the test room and an outlet duct sandwiched between the coil and the outlet temperature grid. This correction is already an industry practice.

7. Water vapor measurements using a dew-point hygrometer, a relative humidity meter, or any other alternative instrument

Today's test procedure explicitly permits alternatives to using wet bulb temperature sensors. To ease instrumentation selection, required instrument accuracies are provided for dew point hygrometers and relative humidity meters.

8. Voltmeter Accuracy

The required accuracy of voltage measurements has been changed from ±2% to ±1%.

9. Electrical Power Measurement

Adjustable-speed-driven motors, as used in a variable-speed compressor, distort the input current and, to a lesser degree, voltage waveforms. Published literature [1-7] supports avoiding the use of induction type meters for measuring such non-sinusoidal power and instead recommends using a meter that is capable of sampling up to the 50th harmonic. This point is included in Section 2.8 of today's test procedure as a recommendation when testing a heat pump or air conditioner having a variable-speed compressor. (In terms of a meter sampling frequency, a 50th harmonic requirement corresponds to a minimum sampling frequency between 3 and 30 kHz, depending upon which technical recommendation you wish to cite.)

The majority of the technical references listed below report the performance of specific meters with specific waveforms, some of which should be representative of those found in presently-marketed residential-size air conditioners and heat pumps. In addition to induction watthour meters, a disconcerting result reported in the noted references is that the use of a non-induction meter that can measure up to the 50th harmonic does not insure an accurate measurement but only improves your chances.

References:

1. P.S. Filipski and R. Arseneau, “Behavior of Wattmeters and Watthour Meters Under Distorted Waveform Conditions,” IEEE tutorial course, Nonsinusoidal Situations: Effects on the Performance of Meters and Definitions of Power, IEEE, Piscataway, NJ, pp. 13-22, 1990.

2. A. Domijan, Jr., E. Embriz-Santander, A.J. Gilani, G. Lamer, C. Stiles, and C.W. Williams, Jr., “Watthour Meter Accuracy Under Controlled Unbalanced Harmonic Voltage and Current Conditions,” IEEE Transactions Power Delivery, Vol. II, No. 1, pp. 64-78, Jan. 1996.

3. A. Domijan, D. Czarkowski, A. Abu-aisheh, and E. Embriz-Santander, “Measurements of Electrical Power Inputs to Variable Speed Motors and Their Solid State Power Converters—Phase II,” ASHRAE Research Project 770, Final Report, November 30, 1995.

4. D. Czarkowski and A. Domijan, Jr., “Performance of Electrical Power Meters and Analyzers in Adjustable-Speed Drive Applications,” American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Transactions 1997, Vol. 103, Part 1.

5. A.J. Baldwin, N.G. Planer, D.E. Nordell, N. Hohan, “Evaluation of Electrical Interference to the Induction Watthour Meter,” EPRI EL-2315, Research Project 1738, Final Report, April 1982.

6. Institute of Electrical and Electronics Engineers (IEEE), Inc., “IEEE Standard 519-1992, IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems,” New York, New York.

7. A. Domijan, and E. Embriz-Santander, “Measurements of Electrical Power Inputs to Variable Speed Motors and Their Solid State Power Converters,” American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Transactions 1993, Vol. 99, Part I, pp. 241-258.

M. Different Compressor Speeds and Indoor Fan Capacities Between Cooling and Heating

In the existing test procedure, variable-speed systems that operate at higher speeds when heating than when cooling are covered. In today's proposed revision (as noted above in III.D.4) this allowance has been extrapolated to coverage of two-capacity heat pumps that only operate at low capacity during the cooling season while using both low and high capacities when heating. And, in taking a generic approach, today's test procedure covers any case where the heat pump uses different fan speeds or air volume rates for cooling versus when heating. (See Section 3.1.4.4.2)

N. Secondary Test Requirements.

When using the Outdoor Air Enthalpy test method, a preliminary test is conducted to compensate, if necessary, for any performance impact caused by the outdoor air-side test apparatus. In accordance with the existing test procedure, a preliminary test is conducted prior to all steady-state tests (i.e., those tests where a secondary measurement of capacity is required). In today's revision, relaxing this requirement is proposed. Section 3.11.1 indicates that the number of preliminary tests can be reduced in most cases to one (for air conditioners or heating-only heat pumps) or two (for heat pumps): one for the first cooling mode steady-state test and one for the first heating mode steady-state test.

O. HSPF Calculations

The last paragraph of Sections 5.2.1 and 5.2.2 of the existing test procedure are not similarly placed in the proposed test procedure. The paragraph in question reads “Once the maximum and minimum HSPF and operating cost values have been obtained for each region, the HSPF and operating cost shall be determined for each standardized design heating requirement (see section 6.2.6) between the maximum and minimum design heating requirements by means of interpolation.” The issue of how many HSPF calculations are required has been, and will remain, an item that is covered elsewhere: In 10 CFR part 430, subpart B, § 430.23(m)(3)(ii). In the proposed test procedure, this section along with a short restatement of its contents are included in the Definition (1.27) for HSPF. Because of the relative ease of automating the calculation process, and the nonlinearity of the HSPF versus design heating requirement relationship, no reference is made to obtaining HSPF or operating cost via interpolation.

V. Procedural Requirements

A. Review Under the National Environmental Policy Act of 1969

In this notice, the Department proposes amendments to the test procedures for central air conditioners and heat pumps. We have reviewed the proposed rule under the National Environmental Policy Act of 1969 (NEPA), 42 U.S.C. 4321 et seq., the regulations of the Council on Environmental Quality, 40 CFR parts 1500-1508, DOE regulations for compliance with NEPA, 10 CFR part 1021, and the Secretarial Policy on the National Environmental Policy Act (June 1994). The Department has determined that this rulemaking is covered under the Categorical Exclusion found at paragraph A.6 of appendix A to subpart D, 10 CFR part 1021, which applies to rulemakings that are strictly procedural. This proposed rule is a procedural rulemaking and its implementation will not affect the quality or distribution of energy usage and therefore will not result in any environmental impacts. Accordingly, neither an environmental assessment nor an environmental impact statement is required.

B. Regulatory Review

Today's regulatory proposal has been determined not to be a “significant regulatory action” under Executive Order 12866, “Regulatory Planning and Review,” (58 FR 51735, October 4, 1993). Accordingly, today's action was not subject to review under the Executive Order by the Office of Information and Regulatory Affairs in the Office of Management and Budget.

C. Regulatory Flexibility Review

The proposed rule has been reviewed under the Regulatory Flexibility Act, (42 U.S.C. 601-612), which requires preparation of a regulatory flexibility analysis for any regulation that will have a significant economic impact on a substantial number of small businesses and other small entities. The proposed rule affects manufacturers of central air conditioners and heat pumps. The test procedures would not have a significant economic impact, but rather, would provide common testing methods. This revision of the test procedure will not require a significant investment for new testing equipment. DOE accordingly certifies that the proposed rule would not, if promulgated, have a significant economic impact on a substantial number of small entities and that preparation of a regulatory flexibility analysis is not required.

D. “Takings” Assessment Review

DOE has determined pursuant to Executive Order 12630 (52 FR 8859, March 18, 1988) that this proposed regulation, if adopted, would not result in any takings which might require compensation under the Fifth Amendment to the United States Constitution.

E. Federalism Review

Executive Order 13132 (64 FR 43255, August 10, 1999) requires agencies to develop an accountable process to ensure meaningful and timely input by State and local officials in the development of regulatory policies that have “federalism implications.” Policies that have federalism implications are defined in the Executive Order to include regulations that have “substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.” On March 14, 2000, DOE published a statement of policy describing the intergovernmental consultation process it will follow in the development of such regulations (65 FR 13735). DOE has examined today's rule and determined that it does not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. No further action is required by the Executive Order.

F. Paperwork Reduction Act Review

This proposed rule contains no new collections of information under the Paperwork Reduction Act, 44 U.S.C. 3501

et seq.

G. Review Under Unfunded Mandates Reform Act of 1995

Section 202 of the Unfunded Mandates Reform Act of 1995 (“Unfunded Mandates Act”) requires that the Department prepare an impact statement before promulgating a rule that includes a Federal mandate that may result in expenditure by state, local, and tribal governments, in the aggregate, or by the private sector, of $100 million or more in any one year. The impact statement must include: (i) Identification of the Federal law under which the rule is promulgated; (ii) a qualitative and quantitative assessment of anticipated costs and benefits of the Federal mandate and an analysis of the extent to which such costs to state, local, and tribal governments may be paid with Federal financial assistance; (iii) if feasible, estimates of the future compliance costs and of any disproportionate budgetary effects the mandate has on particular regions, communities, non-Federal units of government, or sectors of the economy; (iv) if feasible, estimates of the effect on the national economy; and (v) a description of the Department's prior consultation with elected representatives of state, local, and tribal governments and a summary and evaluation of the comments and concerns presented.

The Department has determined that the action proposed today does not include a Federal mandate that may result in estimated costs of $100 million

or more to state, local or to tribal governments in the aggregate or to the private sector. Therefore, the requirements of sections 203 and 204 of the Unfunded Mandates Act do not apply to this action.

H. Review Under Executive Order 12988, “Civil Justice Reform”

With respect to the review of existing regulations and the promulgation of new regulations, section 3(a) of Executive Order 12988, “Civil Justice Reform,” 61 FR 4729 (February 7, 1996), imposes on executive agencies the general duty to adhere to the following requirements: (1) Eliminate drafting errors and ambiguity; (2) write regulations to minimize litigation; and (3) provide a clear legal standard for affected conduct rather than a general standard and promote simplification and burden reduction. With regard to the review required by Section 3(a), section 3(b) of the Executive Order specifically requires that Executive agencies make every reasonable effort to ensure that the regulation: (1) Clearly specifies the preemptive effect, if any; (2) clearly specifies any effect on existing Federal law or regulation; (3) provide a clear legal standard for affected conduct while promoting simplification and burden reduction; (4) specifies the retroactive effect, if any; (5) adequately defines key terms; and (6) addresses other important issues affecting clarity and general draftsmanship under any guidelines issued by the Attorney General. Section 3(c) of the Executive Order requires Executive agencies to review regulations in light of applicable standards section 3(a) and section 3(b) to determine whether they are met or it is unreasonable to meet one or more of them. DOE reviewed today's proposed rulemaking under the standards of section 3 of the Executive Order and determined that, to the extent permitted by law, it meets the requirements of those standards.

I. Review Under the Treasury and General Government Appropriations Act, 1999

Section 654 of the Treasury and General Government Appropriations Act, 1999 (Pub. L. 105-277) requires federal agencies to issue a Family Policymaking Assessment for any proposed rule or policy that may affect family well-being. Today's proposal would not have any impact on the autonomy or integrity of the family as an institution. Accordingly, we have concluded that it is not necessary to prepare a Family Policymaking Assessment.

J. Plain Language Review

The President's Memorandum on “Plain Language in Government Writing,” 63 FR 31885 (June 10, 1998) directs each federal agency to write all published rulemaking documents in plain language. The Memorandum includes general guidance on what constitutes “plain language.” Plain language requirements will vary from one document to another, depending on the intended audience, but all plain language documents should be logically organized and clearly written.

We have tried to make this proposed rule easy to understand. We are also requesting suggestions on how to improve its readability further.

VI. Public Comment Procedures

A. Written Comment Procedures

The Department invites interested persons to participate in the proposed rulemaking by submitting data, comments, or information with respect to the proposed issues set forth in today's proposed rule to Ms. Brenda Edwards-Jones, at the address indicated at the beginning of this notice. We will consider all submittals received by the date specified at the beginning of this notice in developing the final rule.

According to 10 CFR 1004.11, any person submitting information that he or she believes to be confidential and exempt by law from public disclosure should submit one complete copy of the document and ten (10) copies, if possible, from which the information believed to be confidential has been deleted. The Department of Energy will make its own determination with regard to the confidential status of the information and treat it according to its determination.

Factors of interest to the Department when evaluating requests to treat as confidential information that has been submitted include: (1) A description of the items; (2) an indication as to whether and why such items are customarily treated as confidential within the industry; (3) whether the information is generally known by or available from other sources; (4) whether the information has previously been made available to others without obligation concerning its confidentiality; (5) an explanation of the competitive injury to the submitting person which would result from public disclosure; (6) an indication as to when such information might lose its confidential character due to the passage of time; and (7) why disclosure of the information would be contrary to the public interest.

B. Issues for Public Comment

The Department of Energy is interested in receiving comments and data concerning these test procedures. Also, the Department welcomes comments on improvements or alternatives to these approaches. In particular, DOE is interested in gathering comments on the following:

1. Non-defrost (limited-range) heat pumps

Which of the three options described in Section III.A.3 should be invoked?

2. Testing units having a constant-air-volume-rate indoor fan

Are the proposed changes described in Section III.D.1 acceptable? In particular, does the proposed 8 percent tolerance on indoor air volume rate provide a fair balance between assuring repeatable results while not being too restrictive given the variation in blower motor performance?

3. Cyclic testing of units having a variable-speed indoor fan (that may or may not provide a constant air volume rate)

For units that ramp the indoor fan speed when cycling on and/or off, data are sought of the type referenced in the last paragraph of Section IV.C (i.e., data that quantifies the effect on C

from using a ramped air volume rate versus forcing the air volume rate to have a step profile). Also, as described in the second-to-last paragraph of Section IV.C, data from cyclic tests conducted with the indoor fan enabled and disabled are sought.

4. Two-capacity heat pumps that are designed to meet the seasonal cooling load while operating at low capacity

As discussed in the last paragraph of Section III.D.4, should the heat pump be required to have controls that lock out high capacity operation when cooling?

5. Lower limit on the air volume rate used when testing a fanless, two-capacity unit at low compressor capacity

As discussed in Section IV.H.3, data and comments are requested regarding the assigned limit for the air volume rate when testing a fanless, two-capacity unit at low compressor capacity.

Related to this issue is whether the manufacturer should be required to supply, with the unit, the hardware needed to allow the use of two fan speeds on the furnace blower that the unit would be used with in the field. Conceivably, if such hardware was not provided, the test procedure could call for using the same air volume rate for all

tests, regardless of whether the compressor is operating at high or low capacity. On the other extreme, do any manufacturers provide hardware that allows a multi-speed furnace blower to operate as a variable-speed blower? Or, are there safeguards that will result in all or the vast majority of fanless, two-capacity units to be applied with furnaces having variable-speed blowers? If so, then the lower limit noted in the previous paragraph may not be applicable.

6. Fan defaults for fanless (i.e., coil-only) two-capacity units

In the existing test procedure, the fan heat/power default that is applied when rating fanless units is 1250 Btu/h per 1000 SCFM (365 watts per 1000 SCFM). When testing two-capacity fanless units, this adjustment is applied when evaluating space conditioning capacities and electrical power usages for both high and low compressor capacity operation. Do blower curves for multi-speed indoor fans support the use of the same default for both low and high capacity?

7. Differentiation among two-capacity air conditioners and heat pumps

Is there a need to differentiate between two-capacity units that can transition between high and low compressor capacities on-the-fly versus units that must shut off the compressor for some finite time interval when transitioning? Both the existing test procedure and today's proposed revision do not offer a means for providing such differentiation. To begin to do so would require information on how EER and COP are affected as they change from the value associated with steady operation at one compressor capacity until steady operation is obtained at the other compressor capacity following the transition. DOE seeks comments and data that would help to determine whether the test procedure needs to account for low/high compressor transitioning performance.

8. Testing single-packaged units

Today's proposed test procedure includes new test requirements when testing certain types of single-packaged units. The proposed additions are summarized in III.C.1. As presently proposed, the changes are limited to cooling mode tests where all or part of the indoor section is located in the outdoor test room and to heating mode tests where all or part of the outdoor section is located in the indoor test room. Comments are sought on the general proposal and on whether the approaches should be invoked when testing all packaged units.

9. Multi-capacity units

Are there any multi-capacity units that operate at less than maximum speed or high capacity at the lowest outdoor temperatures (prior to cycling off the compressor, if applicable)? Possibly such a strategy is needed to insure component reliability. Such a contingency is not covered in the existing or proposed test procedure.

10. Cyclic degradation coefficients

Comments are sought on the proposed actions discussed above in Section III.D.6 for working towards new C

defaults.

11. NAECA energy conservation standards

Changes introduced in today's proposed test procedure are not expected to cause a minimally-compliant unit to now become non-compliant. If a particular proposed change is found to negatively affect minimally compliant units, then DOE would like to know.

12. Small-duct, high-velocity systems

Comments are sought on the proposed actions discussed in Section III.A.2.

C. Public Workshop

1. Procedures for Submitting Requests to Speak

You will find the time and place of the public workshop listed at the beginning of this notice of proposed rulemaking. The Department invites any person who has an interest in today's notice of proposed rulemaking, or who is a representative of a group or class of persons that has an interest in these proposed issues, to make a request for an opportunity to make an oral presentation. If you would like to attend the public workshop, please notify Ms. Brenda Edwards-Jones at (202) 586-2945. You may hand deliver requests to speak to the address indicated at the beginning of this notice between the hours of 8:00 a.m. and 4:00 p.m., Monday through Friday, except Federal holidays, or send them by mail or e-mail to brenda.edwards-jones@ee.doe.gov.

The person making the request should state why he or she, either individually or as a representative of a group or class of persons, is an appropriate spokesperson, briefly describe the nature of the interest in the rulemaking, and provide a telephone number for contact.

The Department requests each person wishing to speak to submit an advance copy of his or her statement at least 10 days prior to the date of this workshop as indicated at the beginning of this notice. The Department, at its discretion, may permit any person wishing to speak who cannot meet this requirement to participate if that person has made alternative arrangements with the Office of Building Research and Standards in advance. The letter making a request to give an oral presentation must ask for such alternative arrangements.

2. Conduct of Workshop

The workshop (hearing) will be conducted in an informal, conference style. The Department may use a professional facilitator to facilitate discussion, and a court reporter will be present to record the transcript of the meeting. We will present summaries of comments received before the workshop, allow time for presentations by workshop participants, and encourage all interested parties to share their views on issues affecting this rulemaking. Following the workshop, we will provide an additional comment period, during which interested parties will have an opportunity to comment on the proceedings at the workshop, as well as on any aspect of the rulemaking proceeding.

The Department will arrange for a transcript of the workshop and will make the entire record of this rulemaking, including the transcript, available for inspection in the Department's Freedom of Information Reading Room. Any person may purchase a copy of the transcript from the transcribing reporter.

List of Subjects in 10 CFR Part 430

Administrative practice and procedure, Energy conservation, Household appliances, Incorporation by reference.

Issued in Washington, DC., on December 19, 2000.

Dan W. Reicher,

Assistant Secretary, Energy Efficiency and Renewable Energy.

For the reasons set forth in the preamble, part 430 of Chapter II of Title 10, Code of Federal Regulations is proposed to be amended as set forth below:

PART 430—ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

1. The authority citation for Part 430 continues to read as follows:

Authority:

42 U.S.C. 6291-6309; 28 U.S.C. 2461 note.

2. Section 430.22 is amended:

a. By adding paragraphs (b)(5)3. through (b)(5)10.;

b. by adding paragraph (b)(7).

The additions specified above read as follows:

§ 430.22

Reference Sources.

(b) * * *

(5) * * *

3. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 23-1993, “Methods of Testing for Rating Positive Displacement Refrigerant Compressors and Condensing Units.”

4. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 37-1988, “Methods of Testing for Rating Unitary Air-Conditioning and Heat Pump Equipment.”

5. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 41.1-1986 (Reaffirmed 1991), “Standard Method for Temperature Measurement.”

6. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 41.2-1987 (Reaffirmed 1992), “Standard Method for Laboratory Airflow Measurement.”

7. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 41.6-1994, “Method for Measurement of Moist Air Properties.”

8. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 41.9-1988, “A Standard Calorimeter Test Method for Flow Measurement of a Volatile Refrigerant.”

9. American Society of Heating, Refrigerating, and Air-Conditioning Engineers/Air Moving and Conditioning Association, Inc. Standard 51-1999, “Laboratory Methods of Testing Fans for Rating.”

10. American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 116-1995, “Methods of Testing for Rating for Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps.”

(7) Air-Conditioning and Refrigeration Institute (ARI), 4301 North Fairfax Drive, Suite 425, Arlington, Virginia 22203, (703) 524-8800, ARI Standard 210/240-1994, “Unitary Air-Conditioning and Air-Source Heat Pump Equipment.”

3. Appendix M to Subpart B is revised to read as follows:

Appendix M to Subpart B—Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps

1. Definitions

2. Testing Conditions

2.1 Test room requirements

2.2 Test unit installation requirements.

2.2.1 Defrost control settings

2.2.2 Special requirements for units having a multiple-speed outdoor fan.

2.2.3 Special requirements for multi-split air conditioners and heat pumps, and systems composed of multiple mini-split units (outdoor units located side-by-side) that would normally operate using two or more indoor thermostats.

2.2.4 Wet-bulb temperature requirements for the air entering the indoor and outdoor coils.

2.2.4.1 Cooling mode tests.

2.2.4.2 Heating mode tests.

2.2.5 Additional refrigerant charging requirements

2.3 Indoor air volume rates.

2.3.1 Cooling tests.

2.3.2 Heating tests.

2.4 Indoor coil inlet and outlet duct connections.

2.4.1 Outlet plenum for the indoor coil.

2.4.2 Inlet plenum for the indoor unit

2.5 Indoor coil air property measurements and air damper box applications

2.5.1 Test set-up on the inlet side of the indoor coil: for cases where the inlet damper box is installed

2.5.1.1 If the Section 2.4.2 inlet plenum is installed.

2.5.1.2 If the Section 2.4.2 inlet plenum is not installed

2.5.2 Test set-up on the inlet side of the indoor unit: for cases where no inlet damper box is installed.

2.5.3 Indoor coil static pressure difference measurement

2.5.4 Test set-up on the outlet side of the indoor coil.

2.5.4.1 Outlet air damper box placement and requirements

2.5.4.2 Additional recommendations

2.5.5 Dry bulb temperature measurement

2.5.6 Water vapor content measurement

2.5.7 Air damper box performance requirements

2.6 Airflow measuring apparatus

2.7 Electrical voltage supply

2.8 Electrical power and energy measurements

2.9 Time measurements.

2.10 Test apparatus for the secondary space conditioning capacity measurement

2.10.1 Outdoor Air Enthalpy Method

2.10.2 Compressor Calibration Method

2.10.3 Refrigerant Enthalpy Method.

2.11 Measurement of test room ambient conditions

2.12 Measurement of indoor fan speed

2.13 Measurement of barometric pressure

3. Testing Procedures

3.1 General Requirements

3.1.1 Primary and secondary test methods.

3.1.2 Manufacturer-provided equipment overrides.

3.1.3 Airflow through the outdoor coil.

3.1.4 Airflow through the indoor coil.

3.1.4.1 Cooling Certified Air Volume Rate.

3.1.4.1.1 Cooling Certified Air Volume Rate for Ducted Units.

3.1.4.1.2 Cooling Certified Air Volume Rate for Non-ducted Units.

3.1.4.2 Cooling Minimum Air Volume Rate.

3.1.4.3 Cooling Intermediate Air Volume Rate.

3.1.4.4 Heating Certified Air Volume Rate

3.1.4.4.1 Ducted heat pumps where the Heating and Cooling Certified Air Volume Rates are the same.

3.1.4.4.2 Ducted heat pumps where the Heating and Cooling Certified Air Volume Rates are different due to indoor fan operation.

3.1.4.4.3 Ducted heating-only heat pumps.

3.1.4.4.4 Non-ducted heat pumps, including non-ducted heating-only heat pumps.

3.1.4.5 Heating Minimum Air Volume Rate.

3.1.4.6 Heating Intermediate Air Volume Rate.

3.1.4.7 Heating Nominal Air Volume Rate.

3.1.5 Indoor test room requirement when the air surrounding the indoor unit is not supplied from the same source as the air entering the indoor unit.

3.1.6 Air volume rate calculations.

3.1.7 Test sequence.

3.1.8 Requirement for the air temperature distribution leaving the indoor coil.

3.1.9 Control of auxiliary resistive heating elements.

3.2 Cooling mode tests for different types of air conditioners and heat pumps.

3.2.1 Tests for a unit having a single-speed compressor that is tested with a fixed-speed indoor fan installed, with a constant-air-volume-rate indoor fan installed, or with no indoor fan installed.

3.2.2 Tests for a unit having a single-speed compressor and a variable-speed variable-air-volume-rate indoor fan installed.

3.2.2.1 Indoor fan capacity modulation that correlates with the outdoor dry bulb temperature.

3.2.2.2 Indoor fan capacity modulation based on adjusting the sensible to total (S/T) cooling capacity ratio.

3.2.3 Tests for a unit having a two-capacity compressor.

3.2.4 Tests for a unit having a variable-speed compressor.

3.3 Test procedures for steady-state wet coil cooling mode tests

3.4 Test procedures for the optional steady-state dry coil cooling mode tests

3.5 Test procedures for the optional cyclic dry coil cooling mode tests (the D, D

, and I

Tests)

3.5.1 Procedures when testing ducted systems.

3.5.2 Procedures when testing non-ducted systems

3.5.3 Cooling mode cyclic degradation coefficient calculation.

3.6 Heating mode tests for different types of heat pumps, including heating-only heat pumps.

3.6.1 Tests for a heat pump having a single-speed compressor that is tested with a fixed speed indoor fan installed, with a constant-air-volume-rate indoor fan installed, or with no indoor fan installed.

3.6.1.1 Non-defrost heat pump.

3.6.1.2 Heat pump having a heat comfort controller.

3.6.2 Tests for a heat pump having a single-speed compressor and a variable-speed, variable-air-volume-rate indoor fan: capacity modulation correlates with outdoor dry bulb temperature.

3.6.3 Tests for a heat pump having a two-capacity compressor

3.6.4 Tests for a heat pump having a variable-speed compressor.

3.7 Test procedures for steady-state Maximum Temperature and High Temperature heating mode tests (the H0, H0

, H1, H1

, H1

, and H1

Tests).

3.8 Test procedures for the optional cyclic heating mode tests (the H0C

, H1C, and H1C

Tests).

3.8.1 Heating mode cyclic degradation coefficient calculation.

3.9 Test procedures for Frost Accumulation heating mode tests

3.9.1 Average space heating capacity and electrical power calculations

3.9.2 Demand defrost credit

3.10 Test procedures for steady-state Low Temperature heating mode tests

3.11 Additional requirements for the secondary test methods

3.11.1 If using the Outdoor Air Enthalpy Method as the secondary test method

3.11.1.1 If a preliminary test precedes the official test

3.11.1.2 If a preliminary test does not precede the official test

3.11.1.3 Official test

3.11.2 If using the Compressor Calibration Method as the secondary test method

3.11.3 If using the Refrigerant Enthalpy Method as the secondary test method

3.12 Rounding of space conditioning capacities for reporting purposes.

4. Calculations of Seasonal Performance Descriptors

4.1 Seasonal Energy Efficiency Ratio (SEER) Calculations

4.1.1 SEER calculations for an air conditioner or heat pump having a single-speed compressor that was tested with a fixed-speed indoor fan installed, a constant-air-volume-rate indoor fan installed, or with no indoor fan installed

4.1.2 SEER calculations for an air conditioner or heat pump having a single-speed compressor and a variable-speed variable-air-volume-rate indoor fan

4.1.2.1 Units covered by Section 2.1.2.2.1 where indoor fan capacity modulation correlates with the outdoor dry bulb temperature

4.1.2.2 Units covered by Section 2.1.2.2.2 where indoor fan capacity modulation is used to adjust the sensible to total cooling capacity ratio

4.1.3 SEER calculations for an air conditioner or heat pump having a two-capacity compressor.

4.1.3.1 Steady-state space cooling capacity at low compressor capacity is greater than or equal to the building cooling load at temperature T

4.1.3.2 Unit alternates between high (k=2) and low (k=1) compressor capacity to satisfy the building cooling load at temperature T

4.1.3.3 Unit only operates at high (k=2) compressor capacity at temperature T

and its capacity is greater than the building cooling load

4.1.3.4 Unit must operate continuously at high (k=2) compressor capacity at temperature T

4.1.4 SEER calculations for an air conditioner or heat pump having a variable-speed compressor

4.1.4.1 Steady-state space cooling capacity when operating at minimum compressor speed is greater than or equal to the building cooling load at temperature T

4.1.4.2 Unit operates at an intermediate compressor speed (k=i) in order to match the building cooling load at temperature T

4.1.4.3 Unit must operate continuously at maximum (k=2) compressor speed at temperature T

4.2 Heating Seasonal Performance Factor (HSPF) Calculations

4.2.1 Additional steps for calculating the HSPF of a heat pump having a single-speed compressor that was tested with a fixed-speed indoor fan installed, a constant-air-volume-rate indoor fan installed, or with no indoor fan installed

4.2.1.1 Space heating capacity and the electrical power consumption calculations for a non-defrost heat pump

4.2.1.2 Space heating capacity and the electrical power consumption calculations for a heat pump having a heat comfort controller

4.2.2 Additional steps for calculating the HSPF of a heat pump having a single-speed compressor and a variable-speed, variable-air-volume-rate indoor fan.

4.2.3 Additional steps for calculating the HSPF of a heat pump having a two-capacity compressor.

4.2.3.1 Steady-state space heating capacity when operating at low compressor capacity is greater than or equal to the building heating load at temperature T

4.2.3.2 Heat pump alternates between high (k=2) and low (k=1) compressor capacity to satisfy the building heating load at a temperature T

4.2.3.3 Heat pump only operates at high (k=2) compressor capacity at temperature T

and its capacity is greater than the building heating load

4.2.3.4 Heat pump must operate continuously at high (k=2) compressor capacity at temperature T

4.2.4 Additional steps for calculating the HSPF of a heat pump having a variable-speed compressor.

4.2.4.1 Steady-state space heating capacity when operating at minimum compressor speed is greater than or equal to the building heating load at temperature T

4.2.4.2 Heat pump operates at an intermediate compressor speed (k=i) in order to match the building heating load at a temperature T

4.2.4.3 Heat pump must operate continuously at maximum (k=2) compressor speed at temperature T

4.3 Calculations

4.3.1 Calculation of actual regional annual performance factors (APF

) for a particular location and for each standardized design heating requirement

4.3.2 Calculation of representative regional annual performance factors (APF

) for each generalized climatic region and for each standardized design heating requirement

4.4 Rounding of SEER , HSPF, and APF for reporting purposes

1. Definitions

1.1

Annual performance factor

means the total heating and cooling done by a heat pump in a particular region in one year divided by the total electric energy used in one year. Section 430.23(m)(3)(iii) of the Code of Federal Regulations states the calculation requirements for this rating descriptor.

1.2

ARI

means Air-Conditioning and Refrigeration Institute.

1.3

ARI Standard 210/240-94

means the test standard “Unitary Air-Conditioning and Air-Source Heat Pump Equipment” published in 1994 by ARI.

1.4

ASHRAE

means the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

1.5

ASHRAE Standard 23-93

means the test standard “Methods of Testing for Rating Positive Displacement Refrigerant Compressors and Condensing Units” published in 1993 by ASHRAE.

1.6

ASHRAE Standard 37-88

means the test standard “Methods of Testing for Rating Unitary Air-Conditioning and Heat Pump Equipment” published in 1988 by ASHRAE.

1.7

ASHRAE Standard 41.1-86 (RA 91)

means the test standard “Standard Method for Temperature Measurement” published in 1986 and reaffirmed in 1991 by ASHRAE.

1.8

ASHRAE Standard 41.2-87 (RA 92)

means the test standard “Standard Method for Laboratory Airflow Measurement” published in 1987 and reaffirmed in 1992 by ASHRAE.

1.9

ASHRAE Standard 41.9-88

means the test standard “A Standard Calorimeter Test Method for Flow Measurement of a Volatile Refrigerant” published in 1988 by ASHRAE.

1.10

ASHRAE Standard 51-99

means the test standard “Laboratory Methods of Testing Fans for Rating” published in 1999 by ASHRAE and the Air Movement and Control Association, Inc.

1.11

ASHRAE Standard 116-95

means the test standard “Methods of Testing for Rating for Seasonal Efficiency of Unitary Air Conditioners and Heat Pumps” published in 1995 by ASHRAE.

1.12

CFR

means Code of Federal Regulations.

1.13

Constant-air-volume-rate indoor fan

means a fan that varies its operating speed to provide a fixed air volume rate from a ducted system.

1.14

Continuously recorded,

when referring to a dry bulb measurement, means that the specified temperature must be sampled at regular intervals that are equal to or less than the maximum intervals specified in Section 4.3 part “a” of ASHRAE Standard 41.1-86 (RA 91). If such dry bulb temperatures are used only for test room

control, sample at regular intervals that are equal to or less than the maximum intervals specified in Section 4.3 part “b” of the same ASHRAE Standard. Regarding wet bulb temperature, dew point temperature, or relative humidity measurements, continuously recorded means that the measurements must be made at regular intervals that are equal to or less than 1 minute.

1.15

Cooling load factor (CLF)

means the ratio having as its numerator the total cooling delivered during a cyclic operating interval consisting of one ON period and one OFF period. The denominator is the total cooling that would be delivered, given the same ambient conditions, had the unit operated continuously at its steady-state space cooling capacity for the same total time (ON + OFF) interval.

1.16

Coefficient of Performance (COP)

means the ratio of the average rate of space heating delivered to the average rate of electrical energy consumed by the heat pump. These rate quantities must be determined from a single test or, if derived via interpolation, must be tied to a single set of operating conditions. COP is a dimensionless quantity. When determined for a ducted unit tested without an indoor fan installed, COP must include the Section 3.7, 3.8, and 3.9.1 default values for the heat output and power input of a fan motor.

1.17

Cyclic Test

means a test where the unit's compressor is cycled on and off for specific time intervals. A cyclic test provides half the information needed to calculate a degradation coefficient.

1.18

Damper box

means a short section of duct having an air damper that meets the performance requirements of Section 2.5.7.

1.19

Degradation coefficient (C

)

means a parameter used in calculating the part load factor. The degradation coefficient for cooling is denoted by C

. The degradation coefficient for heating is denoted by C

1.20

Demand-defrost control system

means a system that defrosts the heat pump outdoor coil only when measuring a predetermined degradation of performance. The heat pump's controls monitor one or more parameters that always vary with the amount of frost accumulated on the outdoor coil (e.g., coil to air differential temperature, coil differential air pressure, outdoor fan power or current, optical sensors, etc.) at least once for every ten minutes of compressor ON-time when space heating. One acceptable alternative to the criterion given in the prior sentence is a feedback system that measures the length of the defrost period and adjusts defrost frequency accordingly.

In all cases, when the frost parameter(s) reaches a predetermined value, the system initiates a defrost. In a demand-defrost control system, defrosts are terminated based on monitoring a parameter(s) that indicates that frost has been eliminated from the coil.

Systems that vary defrost intervals according to outdoor dry-bulb temperature are not demand defrost systems.

A demand defrost control system, which otherwise meets the above requirements, may allow time-initiated defrosts if, and only if, such defrosts occur after 6 hours of compressor operating time.

1.21

Design heating requirement (DHR)

predicts the space heating load of a residence when subjected to outdoor design conditions. Estimates for the minimum and maximum DHR are provided for six generalized U.S. climatic regions in Section 4.2.

1.22

Dry-coil tests

are cooling mode tests where the wet-bulb temperature of the air supplied to the indoor coil is maintained low enough that no condensate forms on this coil.

1.23

Ducted system

means an air conditioner or heat pump that is designed to be permanently-installed equipment and delivers conditioned air to the indoor space through a duct(s). The air conditioner or heat pump may be either a split system or a single-packaged unit.

1.24

Energy efficiency ratio (EER)

means the ratio of the average rate of space cooling delivered to the average rate of electrical energy consumed by the air conditioner or heat pump. These rate quantities must be determined from a single test or, if derived via interpolation, must be tied to a single set of operating conditions. EER is expressed in units of

EP22JA01.000

When determined for a ducted unit tested without an indoor fan installed, EER must include the Section 3.3 and 3.5.1 default values for the heat output and power input of a fan motor.

1.25

Heating load factor (HLF)

means the ratio having as it numerator the total heating delivered during a cyclic operating interval consisting of one ON period and one OFF period. The denominator is the total heating that would be delivered, given the same ambient conditions, if the unit operated continuously at its steady-state space heating capacity for the same total time (ON + OFF) interval.

1.26

Heat pump having a heat comfort controller

means equipment that regulates the operation of the electric resistance elements to assure that the air temperature leaving the indoor section does not fall below a specified temperature. This specified temperature is usually field adjustable. A method for testing and rating heat pumps having a heat comfort controller is presently limited to heat pumps that meet the equipment criteria of Section 3.6.1.

1.27

Heating seasonal performance factor (HSPF)

means the total space heating required during the space heating season, expressed in Btu's, divided by the total electrical energy consumed by the heat pump system during the same season, expressed in watt-hours. For all heat pumps, HSPF accounts for the heating delivered and the energy consumed by auxiliary resistive elements when operating below the balance point. This condition occurs when the building load exceeds the space heating capacity of the heat pump condenser. For heat pumps with heat comfort controllers (see Definition 1.26), in addition, HSPF also accounts for resistive heating contributed when operating above the balance point as a result of maintaining a minimum supply temperature. Unless an approved alternative rating method is used, as set forth in 10 CFR part 430, subpart B, § 430.24(m), HSPF must be calculated according to this appendix. Repeat the calculations for each of the six generalized U.S. climatic regions listed in this appendix. For each region, evaluate an HSPF for each standardized design heating requirement that applies. (See 10 CFR part 430 subpart B, § 430.23(m)(3)(ii).) The HSPF used to evaluate compliance with the Energy Conservation Standards (see 10 CFR part 430, subpart C, § 430.32(c)) is based on Region IV, the minimum standardized design heating requirement, and the sampling plan stated in 10 CFR part 430, subpart B, § 430.24(m).

1.28

Mini-split air conditioners and heat pumps

means non-ducted systems that have a single outdoor section and one or more indoor sections. The indoor sections cycle on and off in unison in response to a single indoor thermostat.

1.29

Multiple-split air conditioners and heat pumps

means non-ducted systems that have two or more indoor sections. The indoor sections operate independently and can be used to space condition multiple zones in response to multiple indoor thermostats.

1.30

Non-defrost heat pumps

means equipment that is incapable of defrosting the outdoor coil. The equipment ceases to operate the refrigeration system at outdoor temperatures that are conducive to frost accumulation. A method for testing and rating non-defrost heat pumps is presently limited to heat pumps that meet the equipment criteria of Section 3.6.1.

1.31

Non-ducted system

means an air conditioner or heat pump that is designed to be permanently-installed equipment and directly heats or cools air within the conditioned space using one or more indoor coils that are mounted on room walls and/or ceilings. The unit may be of a modular design that allows for combining multiple outdoor coils and compressors to create one overall system. Non-ducted systems covered by this test procedure are all split systems.

1.32

Part-load factor (PLF)

means the ratio of the cyclic energy efficiency ratio (coefficient of performance) to the steady-state energy efficiency ratio (coefficient of performance). Evaluate both energy efficiency ratios (coefficients of performance) based on operation at the same ambient conditions.

1.33

Seasonal energy efficiency ratio (SEER)

means the total heat removed from the conditioned space during the annual space cooling season, expressed in Btu's, divided by the total electrical energy consumed by the air conditioner or heat pump during the same season, expressed in watt-hours. Unless using an approved alternative rating method, as set forth in 10 CFR part 430, subpart B, § 430.24(m), SEER must be calculated according to Section 4.1 of this appendix. [See 10 CFR part 430, subpart B, 430.23(m)(3)(i).] This Section 4.1 SEER and the sampling plan stated in 10 CFR subpart B, 430.24(m) are used to evaluate compliance with the Energy Conservation Standards. (See 10 CFR part 430, subpart C, § 430.32(c).)

1.34

Single-packaged unit

means any central air conditioner or heat pump that has all major assemblies enclosed in one cabinet.

1.35

Split system

means any air conditioner or heat pump that has one or more of the major assemblies separated from the others.

1.36

Standard Air

means dry air at 70 °F and 14.696 psia. Under these conditions, dry air has a mass density of 0.075 lb/ft.

1.37

Steady-state test

means a test where the test conditions are regulated to remain as constant as possible while the unit operates continuously in the same mode.

1.38

Temperature bin

means the 5 °F increments that are used to partition the outdoor dry-bulb temperature ranges of the cooling (≥ 65 °F) and heating (< 65 °F) seasons.

1.39

Test condition tolerance

means the maximum permissible difference between the average value of the measured test parameter and the specified test condition.

1.40

Test operating tolerance

means the maximum permissible range that a measurement may vary over the specified test interval. The difference between the maximum and minimum sampled values must be less than or equal to the specified test operating tolerance.

1.41

Time adaptive defrost control system

is a demand-defrost control system (see Definition 1.20) that measures the length of the prior defrost period(s) and uses that information to automatically determine when to initiate the next defrost cycle.

1.42

Time-temperature defrost control systems

initiate or evaluate initiating a defrost cycle only when a predetermined cumulative compressor ON-time is obtained. This predetermined ON-time is generally a fixed value (

e.g.,

30, 45, 90 minutes) although it may vary based on the measured outdoor dry-bulb temperature. The ON-time counter accumulates if controller measurements (

e.g.,

outdoor temperature, evaporator temperature) indicate that frost formation conditions are present, and it is reset/remains at zero at all other times. In one application of the control scheme, a defrost is initiated whenever the counter time equals the predetermined ON-time. The counter is reset when the defrost cycle is completed. In a second application of the control scheme, one or more parameters are measured (

e.g.,

air and/or refrigerant temperatures) at the predetermined, cumulative, compressor ON-time. A defrost is initiated only if the measured parameter(s) falls within a predetermined range. The ON-time counter is reset regardless of whether a defrost is initiated. If systems of this second type use cumulative ON-time intervals of 10 minutes or less, then the heat pump may qualify as having a demand defrost control system (see Definition 1.20).

1.43

Triple-split system

means an air conditioner or heat pump that is composed of three separate components: An outdoor fan coil section, an indoor fan coil section, and an indoor compressor section.

1.44

Two-capacity (or two-stage) compressor

means an air conditioner or heat pump that has one of the following:

(1) A two-speed compressor,

(2) Two compressors where only one compressor ever operates at a time,

(3) Two compressors where one compressor (Compressor #1) operates at low loads and both compressors (Compressors #1 and #2) operate at high loads but Compressor #2 never operates alone, and

(4) A compressor that is capable of cylinder or scroll unloading.

For such systems,

low capacity

means:

(1) Operating at low compressor speed,

(2) Operating the lower capacity compressor,

(3) Operating Compressor #1, and

(4) Operating with the compressor unloaded (

e.g.,

operating one piston of a two-piston reciprocating compressor, using a fixed fractional volume of the full scroll, etc.).

High capacity

means:

(1) Operating at high compressor speed,

(2) Operating the higher capacity compressor,

(3) Operating Compressors #1 and #2, and

(4) Operating with the compressor loaded (

e.g.,

operating both pistons of a two-piston reciprocating compressor, using the full volume of the scroll).

1.45

Wet-coil test

means a test conducted at test conditions that typically cause water vapor to condense on the test unit evaporator coil.

1.46

Small-duct system

means equipment that contains a blower and indoor coil combination that produces at least 1.5 inches of external static across the indoor unit when operated at the certified air volume rate. When applied in the field, small-duct systems use branch ducts having less than 6.0 square inches of free area.

1.47

ASHRAE Standard 41.6-94

means the test standard “Method for Measurement of Moist Air Properties” published in 1994 by ASHRAE.

2. Testing Conditions

a. This test procedure covers split-type and single-packaged ducted units and split-type non-ducted units. Except for units having a variable-speed compressor, ducted units tested without an indoor fan installed are covered.

b. Only a subset of the sections listed in this test procedure apply when testing and rating a particular unit. Tables 1-A through 1-C show which sections of the test procedure apply to each type of equipment. In each table, look at all four of the Roman—numeral categories to see what test sections apply to your equipment.

1. The first category, Rows I-1 through I-4 of the Tables, pertains to the compressor and indoor fan features of the equipment. After identifying the correct “I” row, find the table cells in the same row that list the type of equipment being tested: Air conditioner (AC), heat pump (HP), or heating-only heat pump (HH). Use the test section(s) listed above each noted table cell for testing and rating the unit.

2. The second category, Rows II-1 and II-2, pertains to the presence or absence of ducts. Row II-1 shows the test procedure sections that apply to ducted systems, and Row II-2 shows those that apply to non-ducted systems.

3. The third category is for special features that may be present in the equipment. When testing units that have one or more of the four (special) equipment features described by the Table footnote for Category III, use Row III to find test sections that apply.

4. The fourth category is for the secondary test method to be used. If you know the secondary method for determining the unit's cooling and/or heating capacity, use Row IV to find the appropriate test sections. Otherwise, include all of the test sections referenced by Row IV cell entries—

i.e.,

sections 2.10 to 2.10.3 and 3.11 to 3.11.3—among those sections consulted for testing and rating information.

c. Obtain a complete listing of all pertinent test sections by recording those sections identified from the four categories above.

d. The user should note that, for many sections, only part of a section applies to the unit being tested. In a few cases, the entire section may not apply. For example, Sections 3.4 to 3.5.3 (which describe optional dry coil tests), are not relevant if the allowed default value for the cooling mode cyclic degradation coefficient is used rather than determining it from testing.

Example for Using Tables 1-A to 1-C.

Equipment Description:

A ducted air conditioner having a single-speed compressor, a fixed-speed indoor fan, and a multi-speed outdoor fan.

Secondary Test Method: Refrigerant Enthalpy Method

Step 1. Determine which of four listed Row “I” options applies ==> Row I-2

Table 1-A: “AC” in Row I-2 is found in the columns for sections 1.1 to 1.47, 2.1 to 2.2, 2.2.4 to 2.2.4.1, 2.2.5, 2.3 to 2.3.1, 2.4 to 2.4.1, 2.5, 2.5.2 to 2.10, and 2.11 to 2.13.

Table 1-B: “AC” is listed in Row I-2 for sections 3 to 3.1.4, 3.1.5 to 3.1.8, 3.2.1, 3.3 to 3.5, 3.5.3, 3.11 and 3.12.

Table 1-C: “AC” is listed in Row I-2 for sections 4.1.1 and 4.4.

Step 2. Equipment is ducted ==> Row II-1

Table 1-A: “AC” is listed in Row II-1 for sections 2.4.2 and 2.5.1 to 2.5.1.2.

Table 1-B: “AC” is listed in Row II-1 for sections 3.1.4.1 to 3.1.4.1.1 and 3.5.1.

Table 1-C: no “AC” listings in Row II-1.

Step 3. Equipment Special Features include multi-speed outdoor fan ==> Row III, M

Table 1-A: “M” is listed in Row III for section 2.2.2

Tables 1-B and 1-C: no “M” listings in Row III.

Step 4. Secondary Test Method is Refrigerant Enthalpy Method ==> Row IV, R

Table 1-A: “R” is listed in Row IV for section 2.10.3

Table 1-B: “R” is listed in Row IV for section 3.11.3

Table 1-C: no “R” listings in Row IV.

Step 5. Cumulative listing of applicable test procedure sections

1.1 to 1.47, 2.1 to 2.2, 2.2.2, 2.2.4 to 2.4.1, 2.2.5, 2.3 to 2.3.1, 2.4 to 2.4.1, 2.4.2, 2.5, 2.5.1 to 2.5.1.2, 2.5.2 to 2.10, 2.10.3, 2.11 to 2.13, 3. to 3.1.4, 3.1.4.1 to 3.1.4.1.1, 3.1.5 to 3.1.8, 3.2.1, 3.3 to 3.5, 3.5.1, 3.5.3, 3.11, 3.11.3, 3.12, 4.1.1, and 4.4.

BILLING CODE 6450-01-P

EP22JA01.001

EP22JA01.002

EP22JA01.003

EP22JA01.004

Inside these test rooms, use artificial loads during cyclic tests and frost accumulation tests, if needed, to produce stabilized room air temperatures. For one room, DOE recommends using an electric resistance heater(s) having a heating capacity that is

approximately equal to the heating capacity of the test unit's condenser. For the second room, DOE recommends using a heater(s) having a capacity that is close to the sensible cooling capacity of the test unit's evaporator. Cycle the heater located in the same room as the test unit evaporator coil ON and OFF when the test unit cycles ON and OFF. Cycle the heater located in the same room as the test unit condensing coil ON and OFF when the test unit cycles OFF and ON.

2.2

Test unit installation requirements.

a. Install the unit according to Section 8.6 of ASHRAE Standard 37-88. With respect to interconnecting tubing used when testing split systems, however, follow the requirements given in Section 5.1.3.5 of ARI Standard 210/240-94. When testing triple-split systems (see Definition 1.43), use the tubing length specified in Section 5.1.3.5 of ARI Standard 210/240-94 to connect the outdoor coil, indoor compressor section, and indoor coil while still meeting the requirement of exposing 10 feet of the tubing to outside conditions. When testing non-ducted systems having multiple indoor coils, connect each indoor fan-coil to the outdoor unit using: a. 25 feet of tubing, or b. tubing furnished by the manufacturer, whichever is longer. If they are needed to make a secondary measurement of capacity, install refrigerant pressure measuring instruments as described in Section 8.6.5 of ASHRAE Standard 37-88. Refer to Section 2.10 of this Appendix to learn which secondary methods require refrigerant pressure measurements. At a minimum, insulate the low pressure line(s) of a split system with foam insulation having an inside diameter that matches the refrigerant tubing and a nominal thickness of

1/2

inch.

b. For units designed for both horizontal and vertical installation or for both up-flow and down-flow vertical installations, the manufacturer must specify the orientation used for testing. Conduct testing with the following installed:

(1) The most restrictive filter(s),

(2) Supplementary heating coils, and

(3) Other equipment specified as part of the unit, including all hardware used by a heat comfort controller if so equipped (see Definition 1.26).

c. Testing a ducted unit without having an indoor air filter installed is permissible as long as the minimum external static pressure requirement is adjusted as Table 2, note 3 states (see Section 3.1.4). Except as noted in Section 3.1.9, prevent the indoor air supplementary heating coils from operating during all tests. For coil only indoor units that are supplied without an enclosure, create an enclosure using 1 inch fiberglass ductboard having a nominal density of 6 pounds per cubic foot. Or alternatively, use some other insulating material having a thermal resistance (“R” value) between 4 and 6 hr·ft\2\·°F/Btu. For units where the coil is housed within an enclosure or cabinet, no extra insulating or sealing is allowed.

2.2.1

Defrost control settings.

Set heat pump defrost controls at the normal settings which most typify those encountered in generalized climatic region IV. (Refer to Figure 2 and Table 17 of Section 4.2 for information on region IV.) For heat pumps that use a time-adaptive defrost control system (see Definition 1.41), the manufacturer must specify the frosting interval to be used during Frost Accumulation tests and provide the procedure for manually initiating the defrost at the specified time. To ease testing of any unit, the manufacturer should provide information and any necessary hardware to manually initiate a defrost cycle.

2.2.2

Special requirements for units having a multiple-speed outdoor fan.

Configure the multiple-speed outdoor fan according to the manufacturer's specifications, and thereafter, leave it unchanged for all tests. The controls of the unit must regulate the operation of the outdoor fan during all lab tests except dry coil cooling mode tests. For dry coil cooling mode tests, the outdoor fan must operate at the same speed as used during the required wet coil test conducted at the same outdoor test conditions.

2.2.3

Special requirements for multi-split air conditioners and heat pumps, and systems composed of multiple mini-split units (outdoor units located side-by-side) that would normally operate using two or more indoor thermostats.

During the steady-state tests, shunt all thermostats to make all indoor fan-coil units operating simultaneously. To ease the testing burden of cyclic tests, consider creating a single control circuit that allows simultaneous cycling of all compressor systems. In this test procedure, references to a single indoor fan, outdoor fan, and compressor means all indoor fans, all outdoor fans, and all compressor systems.

2.2.4

Wet-bulb temperature requirements for the air entering the indoor and outdoor coils.

2.2.4.1

Cooling mode tests.

For wet-coil cooling mode tests, regulate the water vapor content of the air entering the indoor unit to the applicable wet-bulb temperature listed in Tables 3 to 6. As noted in these same tables, achieve a wet-bulb temperature during dry-coil cooling mode tests that results in no condensate forming on the indoor coil. Controlling the water vapor content of the air entering the outdoor side of the unit is not required for cooling mode tests except when testing:

(1) Units that reject condensate to the outdoor coil during wet coil tests. Tables 3-6 list the applicable wet-bulb temperatures.

(2) Single-packaged units where all or part of the indoor section is located in the outdoor test room. The average dew point temperature of the air entering the outdoor coil during wet coil tests must be within ±3.0 °F of the average dew point temperature of the air entering the indoor coil over the 30-minute data collection interval described in Section 3.3. For dry coil tests on such units, you may need to limit the moisture content of the air entering the outdoor side of the unit to meet the requirements of Section 3.4.

2.2.4.2

Heating mode tests.

For heating mode tests, regulate the water vapor content of the air entering the outdoor unit to the applicable wet-bulb temperature listed in Tables 9 to 12. The wet-bulb temperature entering the indoor side of the heat pump must not exceed 60 °F. Additionally, if you use the Outdoor Air Enthalpy test method while testing a single-packaged heat pump where all or part of the outdoor section is located in the indoor test room, adjust the wet-bulb temperature for the air entering the indoor side to yield an indoor-side dew point temperature that is as close as reasonably possible to the dew point temperature of the outdoor-side entering air.

2.2.5

Additional refrigerant charging requirements.

Charging according to the “manufacturer's instructions,” as stated in Section 8.6 of ASHRAE Standard 37-88, means the manufacturer's installation instructions that come packaged with the unit. For third party testing, for example, do not consult the manufacturer about how to charge the unit. If a unit requires charging but the installation instructions do not specify a charging procedure, then evacuate the unit and add the nameplate refrigerant charge. Where the manufacturer's installation instructions contain two sets of refrigerant charging criteria, one for field installations and one for lab testing, use the field installation criteria.

2.3

Indoor air volume rates.

If a unit's controls allow for overspeeding the indoor fan (usually on a temporary basis), take the necessary steps to prevent overspeeding during all tests.

2.3.1

Cooling tests.

a. Set indoor fan control options (e.g., fan motor pin settings, fan motor speed) according to the published installation instructions that are provided with the equipment while meeting the airflow requirements that are specified in paragraph b. of this section.

b. Express the Cooling Certified Air Volume Rate, the Cooling Minimum Air Volume Rate, and the Cooling Intermediate Air Volume Rate in terms of standard air.

2.3.2

Heating tests.

a. If needed, set the indoor fan control options (e.g., fan motor pin settings, fan motor speed) according to the published installation instructions that are provided with the equipment. Do this set-up while meeting all applicable airflow requirements that are specified in paragraph b. of this section.

b. Express the Heating Certified Air Volume Rate, the Heating Minimum Air Volume Rate, the Heating Intermediate Air Volume Rate, and the Heating Nominal Air Volume Rate in terms of standard air.

2.4

Indoor coil inlet and outlet duct connections.

Insulate and/or construct the outlet plenum described in Section 2.4.1 and, if installed, the inlet plenum described in Section 2.4.2 with thermal insulation having a nominal overall resistance (R-value) of at least 19 hr·ft

·°F/Btu.

2.4.1

Outlet plenum for the indoor coil.

Attach a plenum to the outlet of the indoor coil. (Note: For some packaged systems, the indoor coil may be located in the outdoor test room.) For non-ducted systems having multiple indoor coils, attach a plenum to each indoor coil outlet. Add a static pressure tap to each face of the (each) outlet plenum, if rectangular, or at four evenly distributed locations along the circumference of an oval or round plenum. Create a manifold that connects the four static pressure taps. Figure 1 provides recommended options for the manifold configuration. See Figures 7 and 8 of ASHRAE Standard 37-88 for the cross-

sectional dimensions and minimum length of the (each) plenum and the locations for adding the static pressure taps for units tested with and without an indoor fan installed. For a non-ducted system having multiple indoor coils, have all outlet plenums discharge air into a single common duct. At the plane where each plenum enters the common duct, install an adjustable airflow damper and use it to equalize the static pressure in each plenum.

EP22JA01.005

2.4.2

Inlet plenum for the indoor unit.

Install an inlet plenum when testing a coil-only indoor unit or a packaged system where the indoor coil is located in the outdoor test room. Add static pressure taps at the center of each face of this plenum, if rectangular, or at four evenly distributed locations along the circumference of an oval or round plenum. Make a manifold that connects the four static pressure taps. See Figure 8 of ASHRAE Standard 37-88 for cross-sectional dimensions, the minimum length of the inlet plenum, and the locations of the static pressure taps. When testing a ducted unit having an indoor fan (and the indoor coil is in the indoor test room), DOE recommends installing an inlet plenum if sufficient space exists within the test room. If using an inlet plenum, add four static pressure taps and a manifold that connects them together. DOE recommends constructing the inlet plenum and locating the static pressure taps as shown in Figure 8 of ASHRAE Standard 37-88. Never use an inlet plenum when testing a non-ducted system.

2.5

Indoor coil air property measurements and air damper box applications.

a. Measure the dry-bulb temperature and water vapor content of the air entering and leaving the indoor coil. If needed, use an air sampling device to divert air to a sensor(s) that measures the water vapor content of the air. See Figure 2 of ASHRAE Standard 41.1-86 (RA 91) for guidance on constructing an air sampling device. The sampling device may also divert air to a remotely located sensor(s) that measures dry bulb temperature. You may use the air sampling device and the remotely located temperature sensor(s) to determine the entering air dry bulb temperature during any test. You may use the air sampling device and the remotely located leaving air dry bulb temperature sensor(s) for all tests except:

(1) Cyclic tests, and

(2) Frost Accumulation tests.

b. An acceptable alternative in all cases, including the two special cases noted above, is to install a grid of dry bulb temperature sensors within the outlet and inlet ducts. Use a temperature grid to get the average dry bulb temperature at one location, leaving or entering, or when two grids are applied as a thermopile, to directly obtain the temperature difference. A grid of temperature sensors (which may also be used for determining average leaving air dry bulb temperature) is required to measure the temperature distribution within a cross-section of the leaving airstream.

c. Use an inlet and outlet air damper box when testing ducted systems if conducting one or both of the cyclic tests listed in Sections 3.2 and 3.6 . Otherwise, DOE recommends installing an outlet air damper box when testing heat pumps, both ducted and non-ducted, that cycle off the indoor fan during defrost cycles. Never use an inlet damper box when testing a non-ducted system.

2.5.1

Test set-up on the inlet side of the indoor coil: for cases where the inlet damper box is installed.

a: Install the inlet side damper box as specified in Section 2.5.1.1 or 2.5.1.2, whichever applies. Insulate or construct the ductwork between the point where the air damper is installed and where the connection is made to the following:

(1) The inlet plenum (Section 2.5.1.1 units); or

(2) To the indoor unit (Section 2.5.1.2 units) with thermal insulation that has a nominal overall resistance (R-value) of at least 19 hr·ft

·°F/Btu.

b. Locate the grid of entering air dry-bulb temperature sensors, if used, at the inlet of the damper box. Locate the air sampling device, or the sensor used to measure the water vapor content of the inlet air, at a location immediately upstream of the damper box inlet.

2.5.1.1

If the Section 2.4.2 inlet plenum is installed.

Install the inlet damper box upstream of the inlet plenum. The cross-sectional flow area of the damper box must be equal to or greater than the flow area of the inlet plenum. If needed, use an adaptor plate or a transition duct section to connect the damper box with the inlet plenum.

2.5.1.2

If the Section 2.4.2 inlet plenum is not installed.

Install the damper box immediately upstream of the air inlet of the indoor unit. The cross-sectional dimensions of the damper box must be equal to or greater than the dimensions of the indoor unit inlet. If needed, use an adaptor plate or a short transition duct section to connect the damper box with the unit's air inlet. Add static pressure taps at the center of each face of the damper box, if rectangular, or at four evenly distributed locations along the circumference, if oval or round. Locate the pressure taps between the inlet damper and the inlet of the indoor unit. Make a manifold that connects the four static pressure taps.

2.5.2

Test set-up on the inlet side of the indoor unit: for cases where no inlet damper box is installed.

If using the Section 2.4.2 inlet plenum and a grid of dry bulb temperature sensors, mount the grid at a location upstream of the static pressure taps described in Section 2.4.2, preferably at the entrance plane of the inlet plenum. If you do not use the Section 2.4.2 inlet plenum, but you are using a grid of dry bulb temperature sensors, locate the grid approximately 6 inches from the inlet of the indoor coil. Or, in the case of non-ducted units having multiple indoor coils, locate a grid approximately 6 inches from the inlet of each indoor coil. Position an air sampling device, or the sensor used to measure the water vapor content of the inlet air, immediately upstream of the (each) entering air dry-bulb temperature sensor grid. If you are not using a grid of sensors, position the entering air sampling device (or the sensor used to measure the water vapor content of the inlet air) as if the grid were present.

2.5.3

Indoor coil static pressure difference measurement.

Section 6.4.4.1 of ASHRAE Standard 37-88 describes the recommended method for fabricating static pressure taps. Also refer to Figure 2A of ASHRAE Standard 51-99. Use a differential pressure measuring instrument that is accurate to within ±0.01 inches of water and has a resolution of at least 0.01 inches of water to measure the static pressure difference between the indoor coil air inlet and outlet. Connect one side of the differential pressure instrument to the manifolded pressure taps installed in the outlet plenum. Connect the other side of the instrument to the manifolded pressure taps located in either the inlet plenum or incorporated within the air damper box. If you are not using an inlet plenum or inlet damper box, leave the inlet side of the differential pressure instrument open to the surrounding atmosphere. For non-ducted systems that are tested with multiple outlet plenums, measure the static pressure within each outlet plenum relative to the surrounding atmosphere.

2.5.4

Test set-up on the outlet side of the indoor coil.

a: Install an interconnecting duct between the outlet plenum described in Section 2.4.1 and the airflow measuring apparatus described below in Section 2.6. The cross-sectional flow area of the interconnecting duct must be equal to or greater than the flow area of the outlet plenum or the common duct used when testing non-ducted units having multiple indoor coils. If needed, use adaptor plates or transition duct sections to allow the connections. DOE recommends taping joints within the interconnecting duct (and the outlet plenum). Construct or insulate the entire flow section with thermal insulation having a nominal overall resistance (R-value) of at least 19 hr·ft

·°F/Btu.

b. Install a grid(s) of dry-bulb temperature sensors inside the interconnecting duct. Also, install an air sampling device, or the sensor(s) used to measure the water vapor content of the outlet air, inside the interconnecting duct. Locate the dry-bulb temperature grid(s) upstream of the air sampling device [or the in-duct sensor(s) used to measure the water vapor content of the outlet air]. Air that circulates through an air sampling device and passed a remote water-vapor-content sensor(s) must be returned to the interconnecting duct at a point:

(1) Downstream of the air sampling device,

(2) Upstream of the outlet air damper box, if installed, and

(3) Upstream of the Section 2.6 airflow measuring apparatus.

2.5.4.1

Outlet air damper box placement and requirements.

If using an outlet air damper box (see Section 2.5), install it within the interconnecting duct at a location downstream of the location where air from the sampling device is reintroduced or downstream of the in-duct sensor that measures water vapor content of the outlet air. The leakage rate from the combination of the outlet plenum, the closed damper, and the duct section that connects these two components must not exceed 20 cubic feet per minute when a negative pressure of 1 inch of water column is maintained at the plenum's inlet.

2.5.4.2

Additional recommendations.

DOE recommends installing a mixing device(s) upstream of the outlet air, dry-bulb temperature grid (but downstream of the outlet plenum static pressure taps). Also, consider using a perforated screen located between the mixing device and the dry-bulb temperature grid. DOE recommends using a screen having a maximum open area of 40 percent. One or both items should help to

meet the maximum outlet air temperature distribution specified in Section 3.1.8. Mixing devices are described in Sections 6.3—6.5 of ASHRAE Standard 41.1-86 (RA 91) and Section 5.2.2 of ASHRAE Standard 41.2-87 (RA 92).

2.5.5

Dry bulb temperature measurement.

a. Measure dry bulb temperatures as specified in Sections 4, 5, 6.1-6.10, 9, 10, and 11 of ASHRAE Standard 41.1-86 (RA 91). The transient testing requirements cited in Section 4.3 of ASHRAE Standard 41.1-86 (RA 91) apply if conducting a cyclic or Frost Accumulation test.

b. Distribute the sensors of a dry-bulb temperature grid over the entire flow area. DOE recommends using 16 temperature sensors within each temperature grid. The required minimum is 9 sensors per grid. DOE recommends installing redundant inlet and outlet dry bulb temperature sensors and particularly a thermopile. If using thermocouples, DOE recommends the following:

(1) Use 24 gauge wire,

(2) Remove approximately 1 inch of insulation from each lead when preparing to make a junction, and

(3) Use no more than two bonded turns per junction.

2.5.6

Water vapor content measurement.

Deter

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