# - Monday March 14, 

## 1988



# Part II



# epartment of Energy

Office of Conservation and Renewable Energy



## ._-----------_._-- 10 CFR Part 430 Energy Conservation Program for Consumer Products; 

## Final Rulemaking Regarding Test Procedures for Central Air Conditioners, Including Heat Pumps.8304 

### Federal Register / Vol. 53. N'o. 49 / Monday. March 14. 1987 /Rules and Regulations

DEPARTMENT OF ENERGY

Office of Conservation and Renewable Energy

; 1 0 CFR Part 430

[Docket No. CAS-RM-79-1()2]
Energy Conservation Program .10r Consumer Products; Final Rulemaking Regarding Test Procedures lorCentral Air Conditioners, Including Heat Pumps

AGENCY: Office ofConservation and Renewable Energy, DOK

ACTION: Final rule.

SUMMARY: The DepartmentofEnergy (DOE) hereby amends the test procedures for central airconditioners, including heat pumps. Testprocedures

are one part ofthe energy conservation
program for consumer products established pursuant to the Energy Policy and Conservation Act, as amended by the National Energy Conservation Policy Act (NECPA) and the National Appliance Energy ConservationAct (NAECA). Among otherprogram elements, the legislation requires that standard methods of testing be prescribed for covered products.

The purpose oftoday's notice is to improve and refine the test procedure for central air conditions. including heat
pumps. Specifically. DOE is expanding the coverage ofthe test procedures to address innovative designs, including s.plit-type ductless systems and variablespeed central air Qonditioners.

EFFECTIVE DATE: September 12, 1988.

FOR FURTHER INFORMATION CONTACT: Douglass S. Abramson, U.S. Department

ofEnergy. Office ofConservation and Renewable Energy, FOl'restal Building. Mail Station. CE-132, 1000 Independence Avenue SW., Washington. DC 20585. (202) 586-9127 Eugene Margolis. Esq.• U.S. Department

ofEnergy, Office ofGeneral Counsel. FOl'restal Building, Mail Station. GC12.1000Independence Avenue SW.• Washington, DC 20585. (202) 586-9507.

SUPPLEMENTARY INFORMATION:.

a. Background

The energy conservation pr.ogram for

consumerproducts was established pursuant to Title II. Part Dofthe Energy Policy and ConservationAct (EPCA) (Pub. L. 94-163). Subsequently, EPCA

was amended by the National Energy Conservation PolicyAct (NECPA) (Pub. L. 95-619). and the National Appliance Energy Conservation Act of 1987 (NA"SCA) (Pub. L. 100-12). Among other program elements. section 323 ofthe EPCA, as amended. requires that standard methods oftesting be prescribed for covered products. including central air conditioners and heatpumps. Testprocedures appear at 10 CFR Part430, Subpart D.

Testprocedures for evaluating the cooling performance ofair-source central air conditioners were issued initially by DOE on November 21, 1977. 42 FR 60150, November 27, 1977.Test procedures for evaluating the heating performance ofair-source heat pumps as well as amendments to the test procedures for central air conditioners

were issued byDOE on December 10, 1979. 44 FR 76700, December 27, 1979. OnMarch 15. 1985, DOE issued a Notice ofInquiry to solicit comments concerning a rating method for determining efficiency ratings for untested combinations ofsplit-system central air conditioners in lieu of laboratory testing ofsuch units. 50 FR 13042, April 2. 1985. DOE published a proposedrule on October3, 1986, 51 FR 35736, and held a public hearing November 12, 1986. To encourage broad participation in the rulemaking proceeding, DOE extended the comment period to January 30, 1987. 51 FR 40442, November 7, 1986.

Today's rulemaking expands the
coverage ofthe test procedures to address innovative designs, including split-type ductless systems andvariablespeed central air conditioners. Italso prescribes additional requirements for alternative rating methods for estimating efficiency ratings for untested combinations ofsplit-system central air conditioners in lieu oflaboratory testing, by defining the meaning ofa coil family and establishing a requirement for test data to support the results.

In.1981. DOE's Office ofHearings and App-eals (OHA) granted an exception authori:ling a change in the test procedure to York Division Unitary Products (York) for its variable-speed heat pump. Federal Energy Guidelines, 7 DOE No. 81,209. In 1983. OHA extended the exception to Borg-Warner Central Environmental Systems (Borg-Warner), formerly York. Federal Energy Guidelines, 10 DOE No. 81.026. The two exceptions specify an alternative test procedure for evaluating variable-speed heat pumps. In 1986. the Carrier Corporation (Carrier) petitioned the Department for a testprocedure waiver for its variable-speed heat pump. 51 FR 5587, February 14, 1986. DOE granted Carrier's petition on September 19, 1986, approving an alternative test procedure different from the Borg-Warner approach. 51 FR 35403, October 3, 1986. The Department also granted a waiver to the Trane Company for variablespeed heat pumps on March 26, 1987. 52 FR 11855, April 13. 1987. Today's rule establishes a test procedure for variable-speed heat pumps reflecting the methods used in the waivers granted to Carrier andTrane.The exceptions to Borg-Warner and York andwaivers granted to Carrier andTrane by DOE will terminate on the effective date of today's rule.

b. Discussion ofComments

In response to the October 1986 proposal. DOE received comments from manufacturers, utility companies, a trade association. and interested individuals. The major issue.s raised by the comments are discussed below:

1. 

### ContinuousAir TestMethod

The continuous air test method was proposed by DOE to replace the current damper test method. The continuous air
test method eliminates the need for dampers and measures the efficiency of equipment while the fan moves air continuously across the indoor coils. The continuous air test method is based

on American National Standards Institute/American Society ofHeating Refrigerating and Air Conditioning Engineers (ANSI/ASHRAE) Standard 116-1983 andAir Conditioning and Refrigeration Institute (ARI) Standard 210/240-84.

Eleven manufacturers and an industry trade association, the Air Conditioning andRefrigeration Institute (ARI), addressed the issue ofthe continuous air test method.

Manufacturers agreed that the continuous airmethod would be a benefit, provided thatDOE address certain concerns orproblems. The manufacturers' primary concern was that the values for SeasonalEnergy Efficiency Ratio (SEER) orHeating Seasonal Performance Factor (HSPF) rating for existing models ofcentral air conditioners should remain unchanged. This would eliminate the requirement to retest and rerate all equipment. (York, No. 28. at 1; Bard. No. 31. at 1; IEC. No. 32, at 1; ARt No. 39, at 2; Snyder General, No. 41, at 2; Carrier, No. 40. at 4) 1, DOE's proposal would have established the continuous air test method with a six-minute compressor "on" time and a six-minute capacity integration time. (Hereafterreferred to

as the six- and six-method). The capacity integration time is the interval

I Comments on the proposal were given docket numbers and are numbered consecutively, beginning with No. 24. Comments presented at the November 12. 1986. public hearing are identified us Testimony.

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## I Rules and Regulations 8305

during which the cooling or heating capability ofthe airconditionerorheat
pump is measured. However, the ARI Standard 210/240-84 requires a sixminute compressor "on" time with an eight-minute capacity integration time (Hereafter referred to as the six- and eight-method). Nine manufacturers protested the use ofa continuous air method with the DOE six- and sixmethod, recommending the ARI six- and eight-method. (Addision, No. 43. at 2; Lennox, No. 35. at 2; Rheem, No. 29, at 2; ARt No. 39. at 2; Synder General, No. 41, at 2; IEC, No. 32, at 2; Heil Quaker, No. 34, at 2). York commented that the continuous air method with a six- and six-method showed an average 3.8 percent lower SEER rating than the rating achieved with the current damper method. When using a six- and eightmethod the SEER value is 1.85 percent higher than the damper method. (York. No. 28, 

### at 3).

Two commenters considered the additional expense ofretrofitting test facilities to conform to the continuous air test method and testing models in accordance with the proposed test procedure to be excessive and burdensome. (Trane. No. 26, at 5; Addison, No. 43. at 2). These
commenters also argued that the needor requirement to retest old models would add expense and impact negatively on manufacturer research and development.

Also bearing on this issue are the provisions ofthe National Appliance Energy Conservation Act (NAECA) of 1987, which require DOE to revise appropriately the energy conservation standard ofa product when an amended
test procedure would alter the measure ofefficiency on energy use for that product. 

### See Section 323(e).

DOE has examined three possible actions: To adopt the continuous air method with the six- and six-method, to adopt the continuous airmethod with the six- and eight-method, or to retain the current dampermethod. The Department has evaluated the impacts each action would have on the industry and consumers, as well as the energy implications ofeach approach.

DOE believes the adoption ofthe ARI Standard 210/240-84 and ANSI/ ASHRAE Standard 116-1983 continuous air test method (with either six-and sixmethod or six- and eight-method) would

cause disruption oftest facilities, increase manufacturer costs, delay research and development. and require

. DOE to revise the energy conservation

standards in order not to have an impact

on the stringency ofthe legislated minimum efficiency levels. Use of the
current DOE test procedure will allow manufacturers to utilize their test facilities for research and development ofnew products meeting NAECA's minimum efficiency requirements. It also eliminates the various problems of retesting, rerating and redefining the SEER and the HSPF values. The Department believes that although the continuous air method is an adeqlH;lte method oftesting, the current method has achieved a level offamiliarity, confidence, dependability, and reliability over the years. The transition
to the new procedure would surface all the concerns that existed when the
current test procedure was first introduced. For these reasons. DOE has decided not to incorporate ANSI/ ASHRAE Standard 116-83 and ARI Standard 210/240-84, and the proposed cyclic test in today's rule, leaving the damper method in place.



### 2. Degradation Coefficient

Several commenters objected to the proposed change in the assigned value ofthe heating degradation coefficient (CD) from .25 to .35. The York Company (York, No. 28, at 3-4) stated that the change to a .35 value for CD would reduce the HSPF rating in Region IV by five percent. requiring manufacturers to retest. The test burden was seen as excessive by Addison (Addison, No. 43,
at 5 and 8). Four additional commenters objected to changing the value ofCo. (Synder General, No. 41, at 3; ARI, No. 29, at 10; IEC, No. 32. at 2; Bard, No. 31.
at 4). Information provided by the National Bureau ofStandards (NBS) indicated a tendency for Co to differ between heating and cooling by approximately0.1. This information indicates the average value ofthe heating Cnto be between .20 and .30. DOE has reviewed the comments and the NBS analysis and agrees that raising the CD value will result in additional testingwith little increase in the
accuracy ofthe ratings and may, in

some cases, result in less accurate efficiency ratings.

As a result ofthe comments and the review ofthe previous data collected, DOE has decided not to amend the heating degradation coefficient. The value will remain at its designed value of0.25.



### 3. PartLoadFactor

As part ofthe calculation for determining the SEER or HSPF, DOE proposed to change the current part load factor linear method to an exponential method. The Department received four
comments on the issue ofpart load factor. These commenters agreed that DOE should not change the method of determination. Based on the analysis of**l~**
40 basic unit models ofheat pumps and air conditioners, Carrier determined that the impact ofan exponential versus linearpart load factor was smaller than

one percent for both SEER and HSPF. (Carrier, No. 40, at 6). Lennox agreed that this small change in the values was negligible. (Lennox, No. 35, at 4). York concerred that the increase in effort to calculate the part load factor for SEER

orHSPF seemed pointless and
unnecessary. (York. No. 28, at 4). ARI agreed with these comments (ARt No. 39, at 10).

DOE has reviewed these comments and finds that the variance between the present straight line and the proposed exponential method will, in most cases. be absorbed in the rounding ofthe values. making the procedure change
unnecessary. Therefore, DOE is not adopting the exponential method in today's final rule.



### 4. RatingProcedurefor Untested Combinations of Split-System Central Air Conditioners.

The existing regulation for central air conditioners. including heat pumps, allows manufacturers ofuntested combinations ofsplit-systems to rate such systems by engineering analysis methods or computer models developed by the individual manufacturer or a consulting engineering firm. DOE decided to address the issue ofrating untested combinations since each such rating method is unique and there is debate concerning the accuracy ofany particularrating method.

DOE proposed the adoption ofa standard rating procedure for equipment combinations that are not laboratory tested in accordance with Appendix M. -Most commenters addressed the standardrating procedure for untested combinations ofsplit-system central air conditioners. The majority of
commenters favored the use ofa standard method or a privately developed method (alternative method) when itcanbe verified to be more accurate than the standard method, as the desired procedure for rating equipment in lieu oflaboratory testing.

Six commenters favored a standard rating procedure. York, ARI. BARD and Carrier supported the use of the standardprocedure for manufacturers
not in a certification program similar to ARI's. (York, No. 28. at 4; ARt No. 39, at 4; Bard, No. 31, at 4; and Carrier, No. 40,
at 7). While commenters held various opinions concerning implementation. the concept ofutilizing a standardrating procedure was acceptable. Trante (Trane. No. 26, at 7) was concerned with the release or acquisition by other

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## I Rules and Regulations

... I!ll2E

manufacturers ofproprietary information ifa manufacturer's alternative.procedure was submitted to DOE because it was more accurate.

Further comment was received concerning many ofthe components in a combination and the credit which manufacturers should receive in the calculations of the standardrating methodproposed by DOE. These components include fan delay, thermostatic expansion valves. solenoid valves. coil circuitry. and coil configuration. While the comments provided a diversity ofopinion on these subjects. they did not present uniform solutions. Moreover. NBS' evaluationof these comments identified many areas ofresearch required to resolve these issues. In view of the lack ofconsensus in the comments andNBS's need for further research, DOE has decided to omit a standard rating procedure from today's rule. However, DOE has requested NBS to resolve the problems expressed by the commenters. NBS will develop a standardrating procedure to be submitted to DOE for review. After review by DOE. it will be published as

an National Bureau ofStandards Interagency Report (NBSIR), placing it in the public domain, available to any manufacturer or consultant to use in rating untested combinations.

Commenters preferring their own alternative procedure to the standard rating procedure for untested combinations disagreed with the need to submit proprietary information, computer codes, and other historical data that had been very costly to acquire and were concerned about release ofpossible proprietary

- information to competitors. (Addison, No. 43. at 4; Synder General. No. 41, at 5: Magic Aire, No. 30, at 3). Two
commenters stated that the alternative methods used by them are supplied by a consulting firm and that the ability to divulge the consultant's proprietary information to DOE is impractical since these manufacturers do not have access to the programs. (Addison. No. 43. at 4; andBard, No. 31, at4). DOE believes that in these circumstances the consultant can submit the necessary documentation. with the proprietary informationproperly identified, directly
to DOE.

Rheem. anARI member. commented that it wanted the ability to use any raling procedure without approval from DOE as long as the rating was certified under a program similar to ARI's. (Rheem, No. 29, at4).

One commenter. not a member ofARt

was opposed to DOE providing a blanket exemption to ARI members. (First Co., No. 37, at 6). The alternative method should be verified by test data and a complete. detailed description ofthe alternative method with calculated result. (Carrier. No. 40, at 8; Trane. No. 26, at 7; Addison, No. 43. at 4; SynderGeneral, No. 41, at 5).All manufacturer comments opposed submission ofcomputer codes to DOE for evaluation. Several comments were concerned with the·time it would take to review the alternative method and raised the concern that computercodes and other proprietary data might be .made available to competitors. One commenterrecommended that. for purposes ofverification ofthe alternative method, results andtest data shouldbe provided for two condenser units, each with two different coils. This would require four sets oftests to verify the accuracy ofthe alternative rating method. (Carrier, No. 40, at 8).

NBS identified the need for manufacturers to submit sufficient information'to enable DOE to determine the aGCuracy ofthe alternative rating method. NBS believes that, ata minimum, this would require that the rating procedure be traceable to actual and complete test data. that complete documentation ofthe alternative method be provided, including the computer code when a computermodel is used, and that 

### all product-related information be included to allow for DOE ' verification ofratings submitted by the manufacturer.

DOE agrees that the use ofan alternative rating method is appropriate. ifthe alternative rating method is more accurate than a standardizedrating method. The provision to allow the use ofan alternative method ofrating was included as part ofDOE's 1979 central air conditioner final rule. Manufacturers arwrequired to conduct tests of sa·mples ofthe high sales volume combination, condenser and coil, while the alternative rating method is used on other combinations. The alternative rating method represents values determined by computer simulation or engineering analysis as definedby a mechanical
vapor compression refrigeration cycle. The 1979 rule required the alternative rating procedure be submitted to DOE.

Synder General suggested at the public hearing that most manufacturers that submitted alternative rating methods to DOE in 1980 have since amended these methods without resubmitting them for DOE approval. (Testimony, No.1, SynderGeneral. at 12).

This situationprompts DOE to require that all manufacturers that amend alternative rating methods resubmit such methods to DOE in a timely manner for DOE review and approval. The Department also believes that all alternative methods should be resubmittedfor DOE review and approval in orderto maintain integrity in the.ratings. Consequently, manufacturers who previously submitted for use ofan alternative method must resubmit such method to DOE andreceive approval before continuing use ofthe alternative method for rating.central air conditioners_ The approval process is the same in
structure to the current process. The
purpose ofDOE's review and approval
process is to ensure that use of alternative rating methods reslilts in
accurate ratings.

The Department rejects the concerns regarding possible release ofproprietary information. UnderTitle 10 CFR 1004.11, the sensitivity ofproprietary information is protected from release provided the manufacturer identifies properly those sections containing such infprmation. Rating procedures have been submitted
to DOE since 1979. Pursuant to the provisions in DOE's regulations, there have been no instances ofinformation, identified as proprietary. being released by DOE. Therefore, DOE does not share commenters' concerns that proprietary information explaining a manufacturers alternative method will be divulged to third parties. Accordingly, DOE is maintaining the requirement that manufacturers provide full documentation ofalternate rating methods, including that which is considered proprietary. e.g., computer codes, etc., to DOE for approvalprior to the use ofthe ratings in today's rule.

Several commenters stressed the need for accurate data on the various components ofthe system, inaccurate data orinappropriate assumptions could result inlarge errors. Carrier recommended the ability to determine coil capacities by a computer computation/simulation approved by DOE or a test standard such as ASHRAE Standard 33-78. (Carrier, No. 40, at7). The First Company wanted information for the components to be made available by the manufacturer, whereasTrane opposed the divulging of information even to DOE. ofwhat it considers proprietary information, as long as the components are not sold to other manufacturers. (First Co., No. 37,
at 3; Trane, No. 26 at 7).

York suggested that a standardrating method include a coil scaling factor, coil circuitry and heating cycle (York, No. 28,
at 4).

Many commentBrs felt that the two percent tolerance was unrealistic. Trane wanted to maintain the five percenl

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## I Rules and Regulations 8307

tolerance identified in § 430.23(mJ(1) as providing for a 90 percent confidence. with a true mean divided by95 percent. (Trane. No. 26 at 7). Rheem sought the adoption ofa five percent tolerance for
test versus calculation method results. (Rheem. No. 29, at 5). Three coil manufacturers, lEC, Magic Aire. and First Company commented that the proposed rating procedure would force the manufacturer to purchase various condensing units and matched coils for testing prior to making determinations of comparative coils. creating an added
expense. (lEC. No. 32. at 3; Magic Aire. No. 30, at 2; First Company. No. 37. at4).

Itis anticipated that publication ofthe standardrating method as an NBSIR. will enable manufacturers to use it as an alternative to testing oras the basis for

an alternative rating method. DOE believes that development and publication ofa standard method of rating combinations ofcondensers and coils will improve design, replacement selection and make DOE approval of alternative rating methods quick and
easy.

Several commenters addressed the definition ofa coil family in discussing the requirement that test data supporting a manufacturer's alternative method include data for.two complete lines ofcoil families for two condensing units. One commenter stated that a complete coil line (family) included all coils in the same coil configuration (up flow. down flow. orhorizontal) with the

same basic model number and designed for a certain evaporating temperature at

a given capacity (Lennox. No. 35. at 3). York's definition included coils ofa given design (A-coils. airhandlers, horizontal. counterflow orflat top coils) equipped with the same expansion device. Each family could cover a range ofcapacity from one to five tons. (York, No. 28. at4). ARI provided a similar definition. Addison defined a coil family

as all coils used with any specific outdoor condenser unit. [Addison. No. 43. at 2].

DOE has defined a coil family in today's notice. DOE considers a coil family to be a group ofcoils with the

same basic design features that affect the heat exchangerperformance. Those features which identify a coil family are:

(i) Basic configuration (A-shape. Vshape. slanted orflat top coils. etc.)

(ii) Heat transfer surfaces on refrigerant side and air side (flat tubes

vs. grooved tubes. different fin shapes

on air side).

(iii) Tube and fin materials. (iv) Coil circuitry. The family will cover different coil sizes. When a group ofcoils has all these factors in common it is a family. DOE has in today's final rulemaking defined a "coil family" and identified the procedures for acquiring DOE approval ofalternative rating methods for untested combinations of split-type systems. The standard rating method is
not presented in today's notice; however, it will be published as a NBSIR.



### 5. Ground WaterSource Heat Pump and Earth CoupledHeat Pumps

Several commenters maintained that there is no need for a test procedurefor ground water-source or earth-coupled heat pumps (ARt No. 39. at 2; Bard, No. 31, at 4; Friedrich, No. 36, at 1). DOE proposed to incorporate ARI Standard 325-85 which was already in use by ARI and several manufacturers. The acceptance ofthis test pl'Ocedure, with limited changes, would have allowed

consumers to compare the ground water-source, earth-coupled. and air

source centra! airconditionersorheat
pumps.

However. NAECA. enHcted on March 17.1987, defines "central air conditioner" as an "air-cooled product." This requirement eliminates ground
water-source and earth-coupledheat
pumps from the category ofcentral air conditioner and the ratings required of covered products. Therefore, DOE is not including a test procedure for ground
water-source and earth-coupled heat
pumps in today's final rule.



### 6. Split Type Ductless Systems

Two commenters stated that the test procedure for the split-type, ductless systems with multiple coils providing for multiple zones should give credit for
energy savings due to multizoning. (Daikin, No. 27. at 1 and Toshiba, No. 38.
at 2).

DOE does not believe a credit is appropriate since other heating systems having similar capabilities,e.g

.. hydronic and electric resistance heating, receive no credit for this utility feature.

Toshiba discussed the possible combination ofa variable-speed condensing unit with multiple ductless coils. (Toshiba, No. 38, at 2). The test procedure for this system. although not specifically designated. would, in fact, be a combination ofthe split-type ductless system and variable-speed procedures provided in this final rule.

Three commenters stated that the proposed test procedure for the splittype ductless system would be too burdensome. To reduce the testing burden these commenters requested that the definition of "combinations" as proposed be clarified. (IEC. 32 at 5; Toshiba, No. 38, at 14; ARl, No. 39, at 11). DOE agrees that the number of possible combinations would create a burdensome test procedure. For this

reason the testprocedure considers the ability to zone as a utility similar to air conditioners with setback thermostats. Zoning is a consumerpreference. not an efficiency improvement. Therefore. the efficiency ofthe system is analyzed as a single zone. The requirements ofrating by test or alternative method ofvarious combinations ofindoor coils with a single outdoor unit are coveredunder section 430.23, units to be tested. paragraph (m) (1) and (2).

Two-speed outdoorunits for split-type ductless systems will use the two-speed rating procedure with all indoor coils connected as in the single speed rating procedure.

Variable-speed outdoorunits shall be rated according to the variable-speed
test procedure mentioned in today's rule with all indoor coil units connected for all required tests.

The retention ofthe damper method for testing requires that changes be made to the p'roposed test procedure to allow coverage ofsplit-type ductless systems. These changes are required due to the deletion ofthe incorporation ofANSI/ASHRAE Standard 116-1983 and ARI Standard 210/240-84. These
two standards contain information and procedures identifying the basis for the proposed test procedure for split-type ductless system. The cyclic test of ductless units will be performed without dampers. The indoor fan will be turned

on three minutes before compressor "cut-on" and remain on for three minutes after compressor "cut-off." For calculating the cyclic coefficient of performance (COP) the integration time for capacity shall be from compressor "cut-on" time to indoor fan "cut-off' and the integration time for powerwill be the compressor "cut-on" to indoor fan "cut-off' time. The fan powerfor the three minutes after compressor "cut-off' shall be added to the integrated cooling capacity and subtracted from the integrated heating capacity. The indoor coils ofthe ductless system will require the addition ofplenums on the outlets to allow for the measurement ofair flow and the capacity ofthe system.


### 7. DemandDefrost

The present procedure provides an enchancement credit factor equal to 1.07 which is used as a multiplier on capacity
at Tout equal 35°F. This multiplier results

.in an HSPF improvement of approximately four percent according to data submitted to DOE during the 1979 rulemaking.

The proposed rule introduced an enhancementfactor to be applied as a

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## I Rules and Regulations

multiplier directly to HSPF. The multiplier has a maximumvalue of1.04 which is variedbetween 1.04 and 1.00 for single-speed, two-speed and variable-speed systems based on the length oftime between defrost.

ARI and SnyderGeneral expressed support for the existing credit (1.07
X 

### Q(35)). (AR!, No. 39, at 12; Snyder General No. 41. at 3).

Lennox questioned the 90-minute time used in the proposed correlation as the shortest defrost time used in prorating the demand defrost credit butdid not give any alternative suggestion. (Lennox, No. 35, at5).

.

York commented that the proposed procedure fails to recognize the use of auxiliary headduring the defrost cycle. Taking into account that outdoor air relative humidity during the defrost test is much higher than the average relative humidity in region IV, a heatpump will

run a much longer time in the field betweendefrosts than during the frost accumulations test. Correcting for the reduced frequency ofdefrosts with drier weatherincreased the span oftitne between defrosts by a factor of2.8 (a typical demand system would defrost at 3.63 hour intervals at the actual average weather conditions.) A system equipped with a time-temperature defrost control which goes into defrost every 90 minutes wouldrequire 19.6 percentmore power than a demand defrost system at this condition. York concludedbyproposing that the sevenpercent enhancement value for demand control systems be**~etained.** If

### any changes are made. York supports the enhancement that would have a increasedvalue with increased
span time between defrosts. (York, No. 28. at 3).



### Carrierpointed out that the enhancement creditfor variable-speed systems is inconsistent with that prescribedfor single-speed systems. (Carrier. No. 40, at 11). Carrier stated that the amount ofcreditgiven for a demand defrost control shouldbe based

on the ratio ofthe time between defrosts during the frost accumulation test to the maximum time between defrost allowed by the demand defrost controL Carrier proposed the formula:

FD=l+0.04X(1-Ttest-90.0)/Tmax-90.0))
where: " FD=demand defrost credit (used as a multiplier to HSPF) Ttest=test time between defrosts (in minutes)

. Tmax=lesserof720 or the maximum time between defrosts allowed by the unit control (in minutes)


### Trane supported the concept of proportioning the demand defrost with the measured time between defrost terrr{inations. (Trane, No. 26. at4). However. Trane pointedout a lack of consistencyin the time between defrost terminations for different units ofthe

same model, and commented thatthe proposedcorrelation. being very sensitive to this time, may provide significantly different values ofthe damand defrost credit during the rating verification process. In connection with this observation. Trane suggested anotherform ofthe equationfor the demand defrost credit:

Fd=1.03+0:03

### x [(90-Tte,tl!630J



### DOE recognizes that frosting/ defrosting ofa heat pump is a very complex phenomenon governedby system design and controls, operating conditions and sizing. System performance degradation in the frosting region is related to three basic penalties:

1. Degradation ofperformance due to frosting itself; formation offrost on the outdoor coil reduces system instantaneous capacity. and reduces system instantaneous COP.

2. 

### Decrease ofaverage capacity due to the need to perform defrosting ofthe outdoorcoil. The time used by a system to defrost is subtracting from the time that wouldbe used for heating. thus reducing system ability to supply heat. In addition. negative capacity (additional load) is introduced to the house.

3. 

### Use oftemperingheat above the balancepoint. Since delivery ofcold air
to the conditioned space would not be acceptable, an electricheateris used to temperheatpump negative capacity. If 

### defrost occurs above the balancepoint,

use ofthe electricheat degrades system seasonal efficiency.

DOE agrees thatdifferent heatpumps will exhibit different performance degradation due to frosting/defrosting. The three penalties identified above
may have differing shares in performance degradation for different systems.

DOE recognizes that the present rating procedure contains the following simplifications affecting the HSPF rating:

• The procedure does notinclude frosting/defrosting below 17°F outdoor temperature even for time defrost controlled systems, (penalty no. 1 and 2.) Consequently. systemcapacity prescribedinthe procedure is optimistically high (approx. 3-5 percent) for time-defrost heatpumps.

• The procedure does not take into
accountheat tempering above the balancepoint (penalty no. 3.)

A review ofthe comments on demand defrost credit show thatmanufacturers do not have a clearunderstanding ofthe objective ofthe demand defrost credit. DOE believes that demand defrost credit should be applied as compensation for improved performance notmeasured during the defrost testbecause ofhigh humidity specification, and that frosting/defrosting is toocomplex for attempts to describe all three penalties by one correlation. The present procedure takes into account performance degradation due to frosting ofthe outdoor coil (penalty no. 1) through a testat35 OF outdoor temperature. In orderto shorten the defrost test. high outdoorhumidity conditions. more severe than average in the field. wereprescribed. During this
test a system with demanddefrost may not showits full performance potentital.

If

### the time between defrosts is the

same for this unit as ifequipped with a time controlled defrost, a creditis in orderfor the system because full sustem performance ability in field conditions

was not measured during the test. 

### On the otherhand. ifa system with a demand defrost control does not go into defrost at all during the 35 

### OF test. no extra credit shouldbe given to the unit because the test accounted (on a relative basis) for the full performance potential ofthe tested unit. Systems equipped with demand defrost, that defrost during testing but afterthe period allotted to time controlled defrost systems, shouldreceive a creditbased

on a prorated value ofthe actual defrost time versus the duration ofthe defrost
test.

As a result ofthe review ofthe industry comments andperformance data collectedfor ten various models with demand defrost. NBS recommended a revised formula for crediting demand defrost.

1"8=1+0.03X(1-(Ttest-90J/(Tmax-90)) where:
Fd=demand defrost credit (used as a multiplier to HSPF) Ttest=time between defrost terminations in minutes

or 90, whicheveris greater Tmax= maximum time between defrosts allowed by controls in minutes

or 

### no. whichever is smaller


### The correlationprovides three percent credit for a systemwithdemand defrost which has90 minutes orless time between defrost terminations during the frost accumulation test. The amount of credit is linearlyprorated to zero for longer time spansbetweendefrosts. A value ofzero is attainedifthe test time reaches the maximum compressor time allowed by its controls or maximum time prescribed by the procedure (720

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minutes). The value ofthe maximum credit (three percent) was chosen based

on review ofthe HSPF values often heat pumps with a demand defrost credit calculated using the existing procedure and applying a seven precent correction for capacity at the 35 of

### test and comparing to the HSPF for the same units calculated without a seven percent capacitycorrection at the DHRmin in region IV. The seven percent capacity correctionresulted in an HSPS improvement between 2.81 and 2.99 percent.

Based on the information and data provided. DOE has selected the maximum demand defrost credit of 1.03. DOE adopted the revised equation recommended by NBS to determine the value ofthe credit in today's final rule.



### 8. Variable Speed Units

One commenter. KeepRite. proposed adding a test to measure the difference in load matching ability ofvariablespeed units. and outlined the basis for such a test. (KeepRite. No. 33. at 1). KeepRite also recommended that systems with automatic controls and manual controlsbe differentiated. At this time. DOE does not believe there is

a need for a procedure to test-variablespeed systems for loadmatching ability. The test. as outlined by KeepRite, appears difficult to prescribe and burdensome to conduct. Regarding differentiation betweenmanual and automatic controls, DOE does not think that systems with manual controls (in which a homeowner can set speed manually) will be offered in the market place. Therefore. DOE believes the effort
to develop and present a procedure for manual variable-speed is notjustified.

KeepRite commentedthat additional
testpoints are needed at different intermediate speeds to more accurately represent the performance ofvariablespeedunits. (KeepRite. No. 33. at2). Trane showed thatincreasing the number ofintermediate testpointsimproves SEER ofthe tested unit. According to Trane. the impact ofthe number oftestpoints is most significant for the unit ofthe highest maximum speed to minimum speed ratio. For this ratio having the value of3.5. the addition ofthe first intermediate speed
test (to the single-speed procedure) improved the SEERby 11 

### percent. The
next additional point improved the SEER by one percent over the previous value (calculated with one intermediate
test point). An additional third point provided animprovement of approximately0.8 percent. (Trane, No. 26. at 16).

-

Since additional improvement to the SEER rated value decreases significantly with additional intermediate testpoints. adding such points does not seem to be the best solution. Instead. NBS suggested modifications to the proposed method to better account for variable-speed system performance during operationin the intermediate speed region. The DOE proposalused linearinterpolation ofthe powerinputbetween the intermediate speed pOint and the maximum and minimum balance pOints for evaluation of the input power to the unit. NBS suggested using the same points for interpolation but with the following changes: -Performinterpolation using EER or

COP values and then derive the energy input by dividing capacity by EER or COP; -Performparabolic interpolation.

The advantage ofthis approach allows for the interpolation ofEER (COP) versus interpolation ofenergy input.

The procedure relies on three performance points for evaluation ofthe unit performance in the intermediate speed operationrange. The three points

are: -Maximum speedbalancepoint (the

intersectionpointbetween the building load line and the heatpump capacityline at the maximum speed); -Minimum speed balance point (the

intersection pointbetween the building load line and the heatpump capacity line atthe minimum speed); and -Intermediate speed point (the

intersectionpointbetweenthe building loadline and the heatpump capacityline atthe intermediate speed atwhich the unit was tested at 87°F temperature). Atthese three points the unit capacity and power are known. To evaluate powerNBS recommended obtaining powerin the intermediate speedregion through evaluatingEER (COP) at the three points, interpolating EER (COP) at required temperaturebins. andusing the building loads at these temperatures and EERs (COPs).

NBS explainedthat since the capacity line. i.e., thebuilding loadline. is straight. the powerline could also be a straight line ifEER were independent of temperature. IfEER wasprescribedby a linear equation, the powerline equation will be ofa higher order.Thus the complexity ofthe powerline is affected by the complexity ofthe EER line, with the powerline always more complex.

NBS recommends the parabolic interpolation for two reasons: -Unlike the powerline. the EER (COP)

line in the intermediate speedregion may be either convex or concave. A straight line interpolation would unduly benefit systems with intermediate EERs follOWing a

concave line. -From the comments received it



### appears that the EER line is ofthe second orhigher order. Although different systems may have different characteristics. a parabolic fit should give the best estimation ofthe EER line with three data points as input.
Trane commented that the intermediate speed test should be run at

a speed one-third ofthe way between the maximum speed and the minimum speed. (Trane. No. 26. at 17.) Trane's recommendation calis for the same speed in the cooling mode and the heating mode based on the maximum speed andminimum speedin the cooling mode.

Carrier commented that the intermediate speed test should not be fixed. butratherbe specified in terms of minimum andmaximum compressor speeds and respective capacities. (Carrier. No. 40, at 11.)

Lennox commented that the compressor speedat the intermediate speed test should be "tied down" better. perhaps in terms ofinverterfrequency. (Lennox. No. 35, at4.) Carrier supported the proposedintermediate speed tolerance ofplus orminus 10percent. Trane considered this tolerance to be wide and suggestednarrowing it to plus

orminus 5percent. York commented that system capacity atTout=47°Fused for calculation ofthe minimum and maximum DHR shouldbe obtained at the compressor speed corresponding to maximum speedin the coolingmode.

DOE found thatthe speed for the intermediate speedtestproposed in the proposedrule (average betweenthe maximum andminimum compressor speeds) results in a capacity significantly greaterthan the building load at 87°F. Two commenters stated that description ofthe speedbeing onethird between the maximum speed and the minimum speedprovides a reasonable estimate ofthe proper speed for the intermediate speedtest. DOE also concurred with the need toidentify the intermediate speedprecisely to creatl! repeatable tests

..For-this reason the intermediate speed is identifiedin
terms ofinverterfrequency with a tolerance ofplus 5percent orthe next higher step above the calculated speed. The maximum and minimum speeds to be used are those for the cooling mode:
Intermediate speed=min.speed+1h {max. speed-min. speed)

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It

### was suggested that 12 minutes on- time should be allowed only ifthe minimum speed is halfthe maximum speed.The off-time should be 18 minutes
to reflect the decrease off-time variablespeed systems shouldprovide. (Lennox, No. 35, at4.) York commented that
compressoron-time should be increased for variable-speedunits but this increase should not be set arbitrarily to 12 minutes; the amount ofincrease should depend on the maximum to minimum capacityratio. (York, No. 28,
at 6.)

NBS pointed out that the amount of time prescribed as on-time and off-time for the cyclic test, following basic thermostat**relationships~** 

### couldbe evaluated by the equations:

Ton=6minxQmax/Qmin Toff=4xTon



### Following these equations, the time of the cycle would depend on the capacity modulation ration allowing longer ontime (and off-time) for systems with greatercapacity modulation capability. NBS presented data for which a system with capacity modulation ratio oftwo, the penalty is less that five percent, while for a system with capacity modulation ratio ofthree, the penalty is less than 2.5 percent. Consequently, DOE believes that it

### is not practical to prescribe tests longer than one hour(12 minutes on, and48 minutes off). Today's rule includes DOE's determination ofthe following cycle times for variable-speed units for both cooling and heating Ton is 12minutes andTorr48 minutes in order
to retain the 20 percent on-time used in the single speed systemprocedure.

.

Trane suggested adding an optional nominal capacity test to allow the ratings to reflect energy savings of ' systems in which the maximum speedin the heating mode is greaterthan the maximum speed in the cooling mode. Trane suggested defining this nominal capacity as the capacity obtained at the
compressor speed which is the lesser of the maximum speed allowed by controls in the cooling mode and the heating mode. (Trane, No. 26, at 17). DOE has adopted thistest in today's rule as an optional test to be included for manufacturers withunits which have the necessary characteristics to implement this test.

Carrier commented that the procedure should have provision for fan delay. The capacity integration period should include 12 minutes on-time plus the period ofthe fan delay. Similarly, the fan power should be integrated for 12 minutes plus the fan period. (Carrier, No.4, at 11). NBS agreed with this
comment ifDOE decided to retain the damper testmethod. DOE, in its decision to retain the damper method, has concluded thatfan delay for variable-speed systems should be treated the same asJor the current single-speed and two-speed units. This will provide a common perspection for

.units with fan delay verses those without fan delay.

NBS commented that ifHSPF calculations are performed for the maximum design heating requirement, the procedure will underestimate energy inputto the electricheater, overestimating the effic:iency descriptor because the intersectionpoint between the building load**lin~** 

### and the maximum speed capacity line would fall around 35°F temperature. NBS,recommended using the maximum speed capacity line with degradation due to frost accumulation as is done in the procedure for the single-speed systems by applying system capacity, Q(35), and power, E(35), at 35 OF outdoor temperature.

The NBS recommendations include correction factors often percent for capacity and 1.5 percent for power. These factors were selected after a review oftest data ofheat pumps equipped with demand defrost controls. NBS further recommended the tolerance for powermeasurementof0.5 percent be maintained for variable-speed systems.

DOE evaluated the NBS comments on the capacity and energy input lines for determiningHSPF and agrees that the method is sound. Therefore, the variable-speed procedure includes degradation due to frost accumulation at the maximum speed. The capacity and
power ofa variable-speed system at the maximum speed will be evaluatedbased

on performance at 17 OF, .47 OF aHd 35 OF outdoor temperatures.The NBS equntions are includedintoday's rulemaking. '



### 9. Transition Period

Several commenters expressed

concern with the impact ofthe effective date ofthe new procedures and any transitionperiod. Since these comments addressed the implementation ofa new test procedure for single speed and twospeed units other than the damper method, DOE has decided that these

concerns have beenresolved with DOE's decision to retain the damper method.

Since this amendment to the central air conditioner test procedure is concerned only with the demand defrost credit and additional procedures for split-type ductless systems, variablespeed systems, and untested combinations, DOE believes that a transition period is notnecessary. The amendments for new models will be effective 180 days afterpublication in the FederalRegister.

During the periodbetween publication and effe.ctive date, all manufacturers usingan alternative method to rate untested combinations ofcentral air conditioners orheatpumps must submit the necessary data to DOE for review and approval. Failure to receive approval for the alternative rating method will require manufacturers to amend the method oruse testing to rate the equipment. Submittals ofalternative rating methods shouldbe made within three months ofpublication oftoday's rulemaking in orderfor review and approval to be assured by the effective date ofthis amendment. Those manufacturers not receiving approval priorto the effective date, must submit a written request to DOE for an extension.

c. Procedural Matters



### 1. TestProcedures. The test procedures for central air conditioners prescribed today are included in SubpartBofPart430 and are substantially the same a.s those eSlaLlished in the existing procedures with theexception ofthe changes discussed above. Appendix M of SubpartBprovides testprocedures for those models ofcentral air conditioners currently requiring waivers. The changes to appendixM ofSubpart Bdo
not incorporate the ASHRAE and ARI commercial standards contained in the proposed rulemaking, thus the requirements ofthe Federal Energy Administration Act do not apply.



### 2. GeneralPrOllisions. Today's rulemaking contains the definitions of "central air conditioner," and "heat pump" as identified,in NAECA and DOE's definition ofa "coil family."



### 3.Application ofTestProcedures. The
test procedures prescribed today address variable-speed systems and split-type ductless systems. The revision ofthe demand defrost credit in today's notice applies to all system types. The

new procedures will provide ratings comparable to those ratings already receivedpursuant to grantedwaivertest procedures. The compatibility of the

new rating procedures with those established in prior rulemakings creates

no conflictwith the conservation standards established by NAECA.

d. Environmental Review

Pursuant to section 7(c)(2) ofthe Federal Energy Administration Act of 1974, DOE submitted a copy of this notice to the Administrator ofthe Environmental Protection Agency on January 29, 1987, forhis comments

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concerning the impact ofthis proposal

on the quality ofthe environment. A
response. dated April 6. 1987, was received expressing support ofthe rulemaking.

Since test procedures under the
energy conservationprogram for

consumerproducts will be used only to standardize the measurement ofenergy usage. and will not affect the quality of distribution ofenergy usage. prescribing
test procedures will not result in any environmental impacts. DOE, therefore, has determined that prescribing test procedures under the energy conservation program for consumer projects clearly is not a major Federal action significantly affecting the quality ofthe human environment within the meaning ofthe National Environment Policy Act of 1969. Consequently. neither an Environmental Impact Statement nor an Environmental Assessment is required for the final rule.

e. Review UnderExecutive Order 12291

This final rule has been reviewed in accordance with Executive Order 12291 which directs that all regulations achieve their intended goals without imposing unnecessary burdens on the
economy. on individuals. on public or private organizations. oron State and local governments. The Executive Order alsorequires that regulatory impact analyses be prepared for "majorrules." The Executive Orderdefines "major rule"as any regulation that is likely to result in: (1) An annual effect on the
economy of$100 million or more; (2) a major increase in costs orprices for

c·onsumers. individual industries. Federal. State. or local government agencies. or geographic regions; or (3) significant adverse effects on competition. employment. investment. productivity. innovation, or on the ability ofthe United State-based enterprises to compete with foreignbased enterprises in domestic or export markets.

This final rule only amends existing
test procedures for central air conditioners and heat pumps, adding procedures for innovative designs such

as variable-speed heat pumps and split type ductless systems. These procedures only serve to relieve the burden of requesting waivers. Therefore, DOE has determined that any burden imposed on any person. industry. orgovernment entity by the amendment ofexistent procedures, is not sufficient to bring the final rule within the definition of "major rule."
f. Regulatory Flexibility

The Regulatory Flexibility Act, Pub. L. 96-345 (5 U.S.C. 601-612). requires that an agencyprepare an initial regulatory flexibility analysis to bepublished at the time the final rule is published. This requirement (which appears in section 603) does not apply ifthe agency "certifies that the rule will not, if promulgated. have a significant economic impact on a substantial number ofsmall entities." The final rule affects manufacturers ofcentral air conditioners and heat pumps. As previously discussed. the changes will
not have significant economic impacts. but rather will simply improve the test procedures. Furthermore. DOE is not

aware ofany central air conditioner manufacturers that would be considered small entities under the Act. Therefore, DOE certifies that the final rule will not have a "signficant economic impact on a substantiarnumber of small entities." (Energy Policy and Conservation Act, Pub. L. 94-163. as amended by Pub. L. 95-619; and Pub. L. 100-12, Department ofEnergy Organization Act. Pub. L. 95-91J.

List of Subjectsin 10 CFR Part430

Administrative practice and procedures. Energy conservation. Household appliances.

In consideration ofthe foregoing, Part 430 ofChapter II ofTitle 10. Code of Federal Regulations. is amended as set forth below. effective September 12. 1988.

Issued in Washington, DC, March 2, 1988.
Donna R. Fitzpatrick,
AssistantSecretary. Conservation Gild IlenewableEnergy.

PART 430-ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS

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

Authority: Energy Policy and Conservation Act. Title 1II. Part B. as amended by National Energy Conservation Policy Act. Title IV, Part 2, and National Appliance Energy Conservation Act (42 U.S.C. 6291-6309).

2. Section 430.2 is amended by deleting the definitions of "Air-source heat pump". "Cooling only unit". and "Water-source heat pump" and by

. revising the definition of "Central air

conditioner" and "Heatpump" and auding the definition ofa "Coil family"
to read as follows:

§ 430.2 Definitions.

"Cental air conditioner" means a product. other than a packaged terminal air conditioner powered by single phase electric current. which is air-cooled. rated below 55,000 Btu per hour, not contained within the same cabinet as a furnace. the rated capacity ofwhich is above 225.000 Btu per hour, and is a heat
pump or a cooling only unit.

"Heatpump" means a product. other than a packaged terminal heat pump, which consists ofone or more assemblies. powered by single phase electric current. rated below 55,000 Btu
per hour. utilizing an indoor conditioning coil. compressor. and refrigerant-tooutdoor airheat exchanger to provide air heating. and may also provide air cooling. dehumidifying. humidifying circulating. and air cleaning.

"Coil family" means a group ofcoils with the same basic design features that affect the heat exchanger performance. These features are the basic configuration, i.e

.. A-shape. V-shape. slanted or flat top, the heat transfer surfaces on refrigerant and air sides (flat tubes vs. grooved tubes, fin shapes). the tube and fin materials. and the coil circuitry. When a group ofcoils has all these features in common, it constitutes

a "coil family."

3. Section 430.22 is amendetl by revising paragraph (m) to read as follows:

§ 430.22 Test procedures for measures of energy consumption.
* (m) 

### CentaJAirConditioners. (1) The estimated annual operating cost for cool1ng-only units and air-source heut pumps shall be one ofthe following:

(i) For cooling-only units or the cooling portion of the estimated annual operating cost for air-source heat pumps which provide both heating and cooling. the product of: (A) The quotient ofthe cooling capacity. in Btu's per hour. determined fromthe steauy-state wetcoil test (Test A) measured at the highest compressor speed, as describeu in section 3.1 ofAppendix M to this subpart. divided by the seasonal energy efficiency ratio, in Btu's per watt-hour. determined from section 5.1 ofAppentlix M to this subpart; (B) the representative
average use cycle for cooling of 1.000 hours peryear; (C) a conversion factor of0.001 kilowatt per watt; and (D) the representative average unit cost of electricity in dollars perkilowatt-hour

as provided pursuant to section 323(b)(2) of the Act, the resulting product then being rounded offto the nearest dollar
per year;

(ii) For air-source heat pumps which provide only heating or the heating portion ofthe estimated annual operating cost for air-source heat pumps which provide both heating and cooling. the product of: (A) The quotient of the

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standardized design heating requirement, in Btu's per hour, nearest to the capacity measured in the high temperature test, determined in sections 5.2 and 6.2.6 ofAppendix M to this subpart, divided by the heating seasonal performance factor, in Btu's perwatthour, calculated for heating region 

### IV corresponding to the above mentioned standardized design heating requirement determined from section 5.2 ofAppendix M to this subpart; (B) the representative
average use cycle for heating of2,080 hours peryear; (C) the adjustment factor of0.77 which serves to adjust the calculated design heatingrequirement and heating load hours to the actual load experienced by a heating system: (D) a conversion factor of0.001 kilowatt
per watt; and (E) the representative
average unit cost ofelectricity in dollars
per kilowatt-hour as provided pursuant to section 323(b)(2) ofthe Act, the resulting product then being rounded off
to the nearest dollar per year; or

(iii) For air-source heat pumps which provide both heating and cooling, the estimated annual operating cost is the

sum ofthe quantity determined in paragraph (m)(l)(i) ofthis section added
to the quantity determined in paragraph (m)(l)(ii) ofthis section.

(2) The estimated regional annual operating cost for cooling-only units and for air-source heat pumps shall be one of the following:

(i) For cooling-only units or the cooling portion ofthe estimated regional annual operating cost for air-source heat
pumps which provide both heating and cooling, the product of: (A) The quotient ofthe cooling capacity, in Btu's per hour, determined from the steady-state wetcoil test (Test A) measured at the highest compressor speed, as described in section 3.1 ofAppendix M to this subpart, divided by the seasonal energy efficiency ratio, in Btu's per watt-hour, determined from section 5.1 ofAppendix M to this subpart; (B) the estimated number ofregional cooling load hours
peryeardetermined from section 6.1.3 of Appendix M to this subpart; (C) a conversion factor of0.001 kilowatts per watt; and (D) the representative average unit cost ofelectricity in dollars per kilowatt-hour as provided pursuant to section 323(b)(2) ofthe Act, the resulting product then being rounded offto the
nearest dollar peryear;

(ii) For air-source heat pumps which provide only heating or the heating portion ofthe estimated regional annual operating cost for air-source heat pumps which provide both heating and cooling, the product of: (A) The quotient ofthe standardized design heating requirement, in Btu's perhour, nearest to the canacitv measured in the high temperature test (Test A), determined in sections 5.2 and 6.2.6 ofAppendix M to this subpart, divided by the heating seasonal performance factor, in Btu's per watt-hour, calculated for the appropriate region ofinterest and corresponding to the above mentioned standardized design heating requirement determined from section 5.2 ofAppendix M to this subpart; (B) the estimated number ofregional heating load hours
peryear determined from section 6.2.5 of Appendix M to this subpart; (C) the adjustment factor of0.77 which serves to adjust the calculated design heating requirement and heating load hours to the actual load experienced by a heating system; (D) a conversion factor of0.001 kilowatts per watt; and (El the representative average unit cost of electricity in dollars perkilowatt-hour

as provided pursuant to section 323(b)(2) ofthe Act, the resulting product then being rounded offto the nearest dollar
peryear; or

(iii) For air-source heat pumps which provide both heating and cooling, the estimated regional annual operating cost is the sum ofthe quantity determined in paragraph (m)(3)(i) ofthis section added
to the quantity determined in paragraph (m)(3)(ii) ofthis section.

(3) The measurers) ofefficiency for cooling-only units and air-source heat
pumps shall be one or more ofthe following:

(il The seasonal energy efficiency ratio for cooling-only units and airsource heat pumps which provide cooling shall be the seasonal energy efficiency ratio, in Btu's perwatt-hour, determined according to section 5.1 of Appendix M to this subpart, rounded off
to the nearest 0.05.

(ii) The heating seasonal performance factors for air-source heat pumps shall be the heating seasonal performance factors, in Btu's perwatt-hour, determined according to section 5.2 of Appendix M to this subpart for each applicable standardized design heating requirement within each climatic region, rounded offto the nearest 0.05.

(iii) The annual performance factors for air-source heat pumps which provide heating and cooling, shall be the annual performance factors, in Btu's perwatthour, determined according to section 5.3 ofAppendix M to this subpart for each standardized design heating requirement within each climatic region, rounded offto the nearest 0.05.

(4) Otheruseful measures ofenergy consumption for central air conditioners' shall be those measures ofenergy consumption which the Secretary of Energy determines are likely to assist

consumers in making purchasing decisions and which are derived from the application ofAppendix M to this subpart.

(5) After September 12,1988, all

measures ofenergy consumption shall be determined by the test method as sel forth in Appendix M to this subpart; or by an alternate rating method set forth in § 430.23(m)(4) as approved by the Assistant Secretary for Conservation and Renewable Energy in accordance with § 430.23(m)(5).

4. Section430.23 is amended by revising paragraphs (m) (2) through (7)
to read as follows:

§ 430.23 Units to be tested.
* (m) * * * (2) The condenser-evaporator coil combination selected for tests pursuant to paragraph (m)(l) ofthis section shall be that combination manufacturedby the condensing unit manufacturer likely
to have the largest volume ofretail sales. Components ofsimilar design may be substituted without requiring additional testing if the represented

measures ofenergy consumption continue to satisfy the applicable sampling provisions ofparagraphs (m)(l)(i) and (m)(l)(ii) ofthis section. For
every othercondenser-evaporator coil combination manufactured by the same manufacturer or in part by a component manufacturerusing that same condensing unit, either-

(i) A sample of sufficient size, comprised ofproduction units or representing production units, shall be tested to ensure that the requirements of paragraphs (m)(l)(i) and (m)(l)(ii) ofthis section are met for such other condenser-evaporator coil combinations; or

(ii) The representative values ofthe

measures ofenergy consumption shall be based on an alternative rating method that has been approved byDOE in accordance with the provisions of paragraphs (m)(4) and (m)(5) ofthis section.

(3) Whenever the representative values ofthe measures ofenergy consumption, as determined by the provisions ofparagraph (m)(2)(ii) ofthis section, do not agree within five percent ofthe representative values ofthe

measures ofenergy consumption as determined by actual testing, the representativevalues determined by actual testing shall be used to comply with section 323(c) ofthe Act, or to comply with rules prescribed under section 324 of the Act.

(4) The basis ofthe alternative rating method referred to in paragraph (m}(2)(ii) ofthis section shall be a

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representation ofthe test data and calculations ofa mechanical vapor compression refrigeration cycle. The major components in the refrigeration cycle shall be modeled as "fits" to manufacturer performance data orby graphic or tabular performance data. Heat transfer characteristics ofcoils IlIay be modeled as a function offace

area, number ofrows, fins per inch, refrigerant circuitry, airflow rate and entering air enthalpy. Additional performance-related characteristics to be considered may include type of expansion device, refrigerant flow rate through the expansion device, power of the indoorfan and degradation coefficient.

(5) Manufacturers who elect to use an alternative rating method for determining measures ofenergy consumption underparagraphs (m)(2)(ii) and (m)(4) ofthis section must submit a request to DOE for reviewing the alternative rating method to the Assistant Secretary ofConservation and Renewable Energy, 1000 Independence Avenue, SW., Washington, DC 20585, and receive approval to use the alternative method by the Assistant Secretarybefore the alternative method
may be used for rating central air conditioners.

(6) Each request to DOE for reviewing

an alternative rating method shall include:

(i) The name, address and telephone number ofthe official representing the manufacturer.

(ii) Complete documentation ofthe alternative rating procedure, including the computercode when a computer model is used.

(iii) Test data for two coils from two different coil families for two different condensing units. The tested capacities for the matched systems for the two condensingunits shall differ by at least

a factor oftwo. Rating information for the mixed systems shall include the ratings from testing, and from the alternative rating method.

(iv) Complete test data, product information, and related information to allow DOE to verify the rating information submitted by the manufacturer.

(7) Manufacturers that elect to use an alternative rating method for determining measures ofenergy consumption underparagraphs (m)(2)(ii) and (m)(4) ofthis sectionmust either subject a sample oftheir units to independent testing on a regularbasis,
e.g., voluntary certificationprogram, or have the representations reviewed and certified by an independent stateregistered professional engineer who is
not an employee ofthe manufacturer. The registered professional engineeris
to certify that the results ofthe alternative rating procedure accurately represent the energy consumption ofthe unites). The manufacturer is to keep the registered professionalengineer's certifications on file for review by DOE for as long as said combination is made available for sale by the manufacturer. Any change to be made to the alternative rating method. must be approved by DOE prior to its use for rating.

Appendix M to Subpart B-[Amended]

5. Appendix Mto Subpart BofPart 430 is amended by deleting sections 2.4, 3.4, 4.4, 5.4, 5.5, 5.6 and deleting from the seventh paragraph, section 5.2, the
sentence "Forunits with demand defrost control system· * *," revising**th~** headings for sections 2.1, 2.2., 3.1, 3.2, 4.1, and 4.2, adding five sentences at the end ofsection4.1.1.2. adding one sentence at the end of4.2.1.2 and 4.2.1.3, adding a paragraph to the end of section 5.2 and adding sections 2.1.5 through 2.1.7, 2.2.3 through 2.2.5, 3.1.5 through 3.1.7,3.2.3 through 3.2.5, 4.1.1.3 through 4.1.1.5, and 5.1.5, 5.1.6, 5.1.7, 5.2.3, 5.2.4 and 5.2.5. 

### *

2.1 Testing required(orairsource cooling only units. * * *

2.1.5 Testing requiredfor units with triple-capacitycompressors. [Reserved)

2.1.6 Testing required for units with variable-speedcompressors. The tests for variable-speed equipment consist offive (5)
wet coil tests and two (2) dry coil tests. Two ofthe wet coil tests, A and B, are conducted
at the maximum speed. Two wet coil tests, 8. and low temperature test, are conducted at the minimum speed. The fifth wet coil test is conducted at an intermediate speed. Dry coil tests, C and D, are conducted at the minimum speed ifthe coefficient ofdegradation (CD) value of0.25 is not adopted. The test conditions and procedures for the above are outlined in sections 3.1 and 4.1 of this Appendix.

2.1.7 Testing requiredforsplit-type ductless systems. The tests for split-type ductless systems are determined by the type ofcompressorinstalled in the outdoorunit. Por the appropriate tests refer to sections 2.1.1, 2.1.2, 2.1.3, 2.1.4, 2.1.5. or2.1.6 ofthis Appendix.

2.2 Testing required for ail'source heating only units. *

2.2.3 Testing requiredfol' units with triple-capacitycompressors. (Reserved)

2.2.4 Testing requiredfor units with variable-speedcompressors. There are seven basic tests and one optional test for variablespeed units. Three tests (high temperature test, low temperature test, and frost accumulation test) !ul;: iJerformed at the maximum speed. Three tests (two high temperature and one cyclic test) are performed with the unit operating at minimum speed. A second frost accumulation
test is performed at an intermediate speed. The intermediate speed is the same as in the cooling mode.

In lieu ofthe maximum speed frost accumulation test. two equations are provided in section 4.2 ofthis Appendix. In lieu of the cyclic test an assigned value of O.2S may be used for the coefficient of degradation Co. The optional test is a nominal capacity test applicable to units which have a heating mode maximum speed greater than the cooling mode maximum speed. The conditions and procedures for the above tests are described in sections 3.2 and 4.2 respectively, ofthis Appendix.

2.2.5 Testing requiredfor split-type dudless system. The type ofcompressor installed in the outdoor unit determines the testing required, refer to previous sections 2.2.1. 2.2.2,2.2.3, or 2.2.4. The conditions and procedures will be modified as indicated for the various types as stated in sections 3.2 and 4.2 respectively.

3.1 Testing conditionsfor airsource cooling only units.

3.1.5 Testing conditionsfor units with triple-capacity compressors. (Reserved)

3.1.6 Additionaltesting conditionsfor cooling-only units with variable-speed
compressors. Por cooling-only units and airsource heat pumps with varaible-speed
compressors, the air flow rate at fan speeds less than the maximum fan speed shall be determined by using the fan law for a fixed resistance system. The air flow rate is given by the ratio ofthe actual fan speed to the maximum fan speed multiplied by the air flow rate at the maximum fan speed. Minimum static pressure requirements only apply when the fan is running at the maximum speed.

3.1.6.1 Testing conditionsfor steady-state
wetcoil tests. Tests A and Bshall be performed at the maximum speed at conditions specified in section 3.1.1 ofthis Appendix. Test 8. and the low temperature test are performed at the minimum speed with outdoor dry bulb temperatures of82"P and 67"P respectively. The intermediate speed wet coil test is performed at the outdoor dry bulb temperature of87'P. Por units which reject condensate the outdoor
wet bulb temperature shall be maintained at 75'P for Test A. 65'P for Tests Band 8.. 53's"P for the low temperature test and 69'P for the intermediate test. The indoor conditions for all wet coil tests are the same

as those gi\'en in section 3.1.1 ofthis Appendix.

3.1.6.2 Test conditionsfor drycoil tests. Dry coil Tests C and D are conducted at an outdoor dry bulb temperature of67'P. Por units which reject condensate the outdoor
wet bulb temperature shall be maintained at 53.5'P. The indoor dry bulb temperature shall be 80"P and the wet bulb temperature shall be sufficiently low so no condensation occurs

on the evaporator (It is recommended that an indoor wet bulb temperature of57"P or less be used).

### 8314 Federal Register 

## I Vol. 53, No. 49 

## I Monday, March 14, 1987 / Rules and Regulations

3.1.7 Split-type ductless systems. Test conditions shall be the same as those specified for the same single outdoor unit
compressor type, assuming it was matched with a single indoor coil.

3.1.7.1 Interconnection. For split-type ductless systems. all standard rating tests shall be performed with a minimum length of 25 feet ofinterconnecting tubing between each indoor fan-coil unit and the common outdoor unit. Such equipment in which the interconnection tubing is furnished as an integral part of the machine not recommended for cutting to length shall be tested with complete length oftubing furnished, or with 25 feet oftubing, whichever is greater. At least 10 feet ofthe interconnection tubing shall be exposed to the outside conditions. The line sizes, insulation and details ofinstallation shall be in accordance with the manufacturer's published recommendation.

3.1.7.2 Control testing conditionsfor splittype ductless systems. For split-type ductless systems, a single control circuit shall be substituted for any multiple thermostats in order to maintain a uniform cycling rate during test D and the high temperature heating cyclic test. During the steady-state tests, all thermostats shall be shunted resulting in all indoor fan-coil units being in operation.

3.1.7.3 Split-type ductless systems with multiple coils ormultipledischarge outlets shallhaveshortplenumsattachedto each outlet. Each plenum shall discharge into a single common duct section. the duct section in turn discharging into the air measuring device (or a suitable dampering device when direct air measurement is not employed). Each plenum shall have an adjustable restrictor located in the plane where the plenums enterthe common duct section for the purpose ofequalizing the static pressures in each plenum. The length of the plenum is a minimum of2.5x(AXB)·5. A=width and B=height ofduct or outlet. Staticpressure readings are taken at a distance of 2X(AxBj,5from the outlet.

3.2 Testing conditionsfor airsource heating only units.* *

3.2.3 Testing conditionsfor units with triple-capacitycompressors. (Reserved)

3.2.4 Testing conditionsfor units with variable-speedcompressors. The testing condition for variable-speed compressors shall be the same as those for single speed units as described in section 3.2.1 ofthis Appendix with the following exceptions; the cyclic test is performed with an outdoor dry bulb temperature of62°F and a wetbulb temperature of'56.5'F. The optional. nominal capacity test shall be performed at the conditions specified for the 47°F high temperature test.

3.2.5 Testing conditionsforsplit-type ductless system. The testing conditions for split-type ductless systems shall be based on the type ofcompressorinstalled in the single outdoor unit. The heating mode shall have the

same piping and control requirements as in 3.1.7.

4.1 Testproceduresfor ail'source cooling-oIlly units.
*

4.1.1.2 * •• Cooling cyclic tests for variable-speed units shall be conducted by cycling the .'
compressor 12 minutes "on" and 48 minutes "off'. The capacity shall be measured for the integration time (8), which is the compressor "on" time of12 minutes or the "on" time as extended by fan delay, ifso equipped. The electrical energy shall be measured for the total integration time (8
e• e) of60 minutes. In lieu ofconducting C and D tests, an assigned value of0.25 shall be used for the degradalion coefficient for cooling, Co.

4.1.1.3 Testingproceduresfor triplecapacity compressors. (Reserved)

4.1.1.4 Intermediate cooling steady-state
testfor units with variable-speed
compressors. For units with variable-speed
compressors, an intermediate cooling steadystate test shall be conducted in which the unit shall be operated at a constant, intermediate compressor speed (k=i) in which the dry/bulb and wet-bulb temperatures ofthe air entering the indoor coil are 80'FoB and 67'FwB and the outdoor coil are 87°0B and 69'FwB' The tolerances for the dry-bulb and wet-bulb temperatures of the air entering the indoor and outdoor coils shall be the test operating tolerance and test condition tolerance specified in Table 6.1.1 of this Appendix. The intermediate compressor speed shall be the minimum compressor speed plus one-third the difference between the maximum and minimum speeds ofthe cooling mode. (Inter. speed=min. speed+ 1/3 (max. speed-min. speed.) A tolerance ofplus five percent or the next higher inverter frequency step from that calculated is allowed.

4.1.1.5 Testingproceduresfor split-type ductless systems. Cyclic tests ofductless units will be conducted without dampers. The data cycle shall be preceded by a minimum oftwo cycles in which the indoor fan cycles

on and offwith the compressor. For the data cycle the indoor fan will operate three minutes prior to compressor cut-on and' remain on for three minutes after compressor cut-off. The integration lime for capacity and
power shall be from compressor cut-on time
to indoor fan cut-offtime. The fan power for three minutes after compressor cut-off shall be added to the integrated cooling capacity.

4.2 Testingproceduresfor ali'source heating only units.

4.2.1.2 * * * The cycle times for variable-speed units is the same as the cyclic time in the cooling mode'as specified in section4.1.1.2 ofthis Appendix. Cyclic tests of split-type ductless units will be conducted without dampers, and the data cycle shall be preceded by a minimum oftwo cycles in which the indoor fan cycles on and offwith the compressor. During the data cycle for the split type ductless units, the indoor fan will operate three minutes prior to compressor "cut-on" and remain on for three minutes after
compressor "cut-off'. The integration time for capacity and power will be from compressor "cut-on" time to indoor fan "cut-oft" time. The fan power for the three minutes after
compressor "cut-off' shall be subtracted from the integrated heating capacity. For split-type ductless systems which turn the indoor fan offduring defrost, the indoor supply duct shall not be blocked.

4.2.1.3 * * * For units with variable-speed compressors, the frost accumulation test at the intermediate speed shall be conducted such that the unit will operate at a constant, intermediate compressor speed (k=iJ as determined in section4.1.1.4 ofthis Appendix. The following two equations may be usedin lieu ofthe frost accumulation test for variable-speed.



# (a) k=2 

# o (35)



## def k=2 k=2 k=2 

# X

.

= 

### 0.90)\ 

## [0 (17)+(0 (47)-0 (17»] (35-17)/(47-17)

k=2 

### E (35)



## def 55 55 55



## V k=2 k=2 k=2

.
= 

### 0.985" [E (17)+(E (47)-E (17»]

# X (35-17)/(47-17)

55 55 55

### FederalRegister / Vol. 53, No. 49 / Monday, March 14, 1987 / Rules and Regulations 

### 8315

*5.1.5 Seasonal energyefficiencyratiofor air-source units with triple-capacity
compressors. (Reserved)

5.1.6 Seasonal energyefficiencyratiofor air-source units with variable-speed
compressors. For air-source units with variable-speed compressors. the sasonal
energy efficiency ratio (SEER). shall be defined as follows: 

### SEER 

### 8 

# L:

j=l

= 

# L: 8

j=l



## +

- Qk=l(82 

## ss 82

- 67 Q(Tj)

N



### E (Tj) where the number ofhours in the ith temperature bin (nj)/N is defined inTable 6.1.2 ofthis Appendix.

The SEER shall be determined by evaluating three cases ofthe compressor operalion. Case Iis the same as specified in 5.1.3.1 with the exception that the quantities QSl=l(T;) andEssk=l(T j) shall be calculated by the following**eq~ations:**



# -N

F) 

### X(82-T.) 

### J

Ek=l(T.) = Ek=1(82 F)



## ss J 

## ss +
Ek=1(67 F) 

### Ek=1(82 F

_S_S

__ -:::-:-_-:" :-::S,-S_....:...

__ ) )( 

### (82

- T.)

Case II is when the compressor operates at any intermediate (k=v) speedbetween the maximum (k=2) and minimum (k=l) speeds
to satisfy the building cooling load. Evaluate the following equations: 

### k=v Q

SS 

### (T

### j ) 

### =BL(T.) ]



### =

# Q~~v (Tj ) 

# X nj


## N

where Esl=V(T;) the electrical power input required by the unit to delivercapacity matching the building load at temperature T J• 

### 82 67 J

whereQssk=V(T;)= the capacity delivered by the unit matching the building load at temperature Tj. EERssk=V(Tj) = the steady-state energy efficiency ratio at temperature T jand an intermediate speed at which the unit capacity matches the building load.
Before the steady-state intermediate speed
energy efficiency ratio, EERsl=V(T;), can be calculated, the unit performance has to be evaluated at the compressor speed (k=i) at which the intermediate speed test was conducted.The capacity ofthe unit at any temperature T jwhen the compressor operates
at the intermediate speed (k=i) may be determined by:

Where: QSSk=i(87)= the capacity ofthe unit at 87 QF determined by the intermediate cooling steady-state test. MQ=slope ofthe capacity curve for the intermediate compressor speed (k=i)**~** Ok s=s2(95 l - Qk=2(B2l

+ N " ss Q 95

- 82

Once the equation for Q •."=i(Tj) has been determined, the temperature where Q • ."=i(Tj) =BL(T j) canbe found. Thrs temperature is designated as (Tvc). The electrical power input for the unit operating at the intermediate compressor speed (k=i) and the temperature (Tvc) is determinedby:

where:

### 8316 Federal Register / Vol. 53. No. 49 / Monday. March 14. 1987 / Rules and Regulations

E"k=i(87)=the electrical powerinput ofthe unit at 87'F determined by the intermediate cooling steady-state test ME=scope ofthe electricalpowerinput curve for the intermediate compressor speed (hi)

Ek=1(82) _ Ek=1(67)

55 55 

# X (1 N M,E 

### =-:;.;:;.-----'--'---

- r;) 82

- 67

Ek=2(95) _ Ek=2(82)

55 55 + NE -:;.;:;.--9-5----8-2-'----

The energy efficiency ratio ofthe unit. EER••(Tvcl. at the intermediate speed (k=i) and temperature Tvc canbe calculated by the equation:



### k=i k- i 

### Q

### ss (Tvc) E ER

- (T ) 

# =------ ss vc Similarly. energy efficiency ratios at temperaturesTl and T. canbe calculated by the equations:

where: 

### Qk=2(T )
ss 2



### Ek=2(T )

ss 2

T. = temperature atwhich the unit. operating
at the minimum compressor speed. delivers capacity equal to the building load (Q,r'(T,)=BL(Tz)). found by " equating the capacity equation [(Q,r'(Tjl] and building load equation [BL (T j)) in section 5.1.3 and solving for temperature. T2 =temperature at which the unit. operating
at the maximum compressor speed. delivers capacity equal to the building load (Q"k=,,{T2)=BL (T 2)). found by equating the capacity equation [(Q.,k=2 (T

j)] and the building equation [BL (Tjll in section 5.1.3 and solving for temperature.



### B

# EER~:tT1)-**EER~:lT2)-** 0

# (EER~:tT1)- = T1

- T2

- 

# oX (T1 TVC>**EERssk~I(Ttl=the** steady state energy efficiency ratio atthe minimum
compressor speed at temperature 1\. EER

ssk="{T 2}=the steady state energy efficiency ratio atthe maximum
compressor speed at temperature 1'2. E

ssk=I(Til=the electricalpowerinput atthe minimum compressor speed at temperature T•• calculated by the equationin section 5.1.3. E

s,k=,,{T2 }= the electrical powerinput atthe maximum compressor speed at temperature T2• calculatedby the equation in section 5.1.3.
The energy efficiency ratio. EER••k=v(T j}. shall be calculatedby the following equation:

where coefficients A. B. and C shall be evaluatedusing the following calculation steps:



# o 

# =

EERk= 

### i (T 

## » ss vc

EERk=lCT ) k=2 - B

# ~ ('1'1 - T 2 ) 

# C ss 1 EERss (T2 )

=

A 

### = k=2 EERss (T2 )

Case IIIis the same as specified in 5.1.3.4. The quantities Q

.. k='(T j) and E

.. k="{T j) and E

..

k="{Tj) shallbe calculatedbythe equations prescribedin 5.1.3.

5.1.7 Seasonalenergyefficiencyrationfor split-typeductless systems. For split-type ductless systems. SEER shall be defined as specified in section 5.1.1 ofthis Appendix for eachcombination setofindoorcoils to be used with a common outdoorunit. 

### T2 1 T2 2

-B)(T2 

# -CX T2 2

5.2' •• For air-source units that are equippedwith "demanddefrost control systems". the ,value for HSPF. as determined above shallbe multiplied by an enhancementfactor Fd.!to compensate for improved performance not measured in the Frost Accumulation Test. The factor. F de! depends on the number of defrost cycles in a 12-hourperiod and should becalculated as follows:
F**det~l**+0.03X(1- (Ttest-90)/(T max-90)) where:
Fder=demanddefrost credit (used as a' multiplier to HSPF) T,••t=timebetween defrost terminations in minutes or90. (whichever is greater)

### Federal Register / Vol. 53, No. 49 / Monday, March 14, 1987 / Rules and Regulations 

### 8317

Tm

..=maximum time betweendefrosts -allowed by controls. (in minutes or720 (whicheveris**les~)**



### HSPF 

# = 5.2.3 Heating seasollalperfol1nance factorfor air-source units with triplecapacitycompressors. (Reserved)

5.2.4 Heating seasonalpelforlIloilce factorfor units with variable-speed 

# L:' n· J BL (T

### j) J 

## N 

# (L
j E (T

### j) 

# LRH (T .)

# )

+ j J

where: all symbols in the above equations are

as defined in 5.2

..2. The minimum and maximum heating design requirements, DIIRmin andDHRma" which a variable-speed heat pump is likely to encounter, shall be evaluated as described for two-speed units in 5.2.2. with the option of using the nominal capacity,**Qssk~n(47°** F). in lieu ofthe maximum speed capacity,**Qssk~"(47),** in the prescribed equations ifthe 

### N

(T .) 

### J

Case II

The compressor operates at any intermediate [k=v) speed between the maximum speed (k=2) and minimum (k=l) speed to satisfy the building load.

Evaluate the following equations: 

### N

manufacturer performed the nominal capacity
test.

In evaluation ofHSPF, three cases are considered, the quantities E (TIN;) and RH(T/Nj ) shall be calculated depending on compressormode ofoperation.

Case I

The compressor operates at the minimum speed (k=lJ for which the building heating



## 15

=

## E~~1(47) 

## +

15

k=v Q (Tj ) = BL(Tj )

Q(Tj) = Qk=v (Tj) 

# X nj


### N 

### N

where: Qk=V(T.} - J

3.413 Xcopk=V(Tj )

Ek=v(T.)

# X n· J J 

### N compressors. For units with variable-speed
compressors, the heating seasonal performance factor (IISPF) is defined by the following equation:

load, BL(Tj ), is less than or equal to the heating capacity, Qssk=l(T;).

Calculations shall be performed <IS prescribed for two-speed systems in Case I of 5.2.2. with the exception that system capacity Q" k= '(Tj ), and power. Essk=

### '0:;). shall be calculated by the following equeations:



### (T .-47) 

### J

(T

.-47) 

## J

Qko " (Tj ) = capacity delivered by the unit at any intermediate speed between the minimum and maximum compressor speed matching the building load at temperature TJ Ek=V(TJ)=the clectricai powerinput required by the unit at temperature Tj to deliver capacity matching the building load COPk='(T;)=the coefficient ofperformance at which the unit delivers capacity matching the building load at temperatureTj Defore the coefficient ofperformance. COPk=V(T j ), can be calculated, the unit performance has to be evaluated at the
compressor speed (k=i) at which the intermediate speed lest was conducted. The capacity ofthe unit at any temperatureT when compressor operates at the

### 8318 Federal Register 

## I Vol. 53. 

### No. 49 

## I Monday, March 14. 1987- 

## I Rules and Regulations

intermediate speed [k=i) may be determined by:

k=i k=i Qde,[TJ)= Qde'[35)

### +MQ[Tj

- 35) where: k=i Qde,(35)= the capacity of the unit at 35'F determined at the intermediate
compressor speed**[k,~**iJ in the frost accumulation test



## k=1 MQ= slope ofthe capacity curve for the intermediate compressor speed [k=i)



### (62) 

## Qk=1 (47) Q

ss ss 

# )( MQ = (1 - N Q

)

+ 

## N Q

N

Q =

Once the equation for Qk=i[T j)has been determined. the temperature where Qde/=i[Tj) =BL[Tj ) can be found. This temperature is designated at Tvh' A separate Tvh shall be determined for each design heating requirement.



## ME =

+ 

## NE 62 

## 47

k=2 

## Qdef (35) 

## k=2 Q

## ss (17)

35 17



## k= i Qdef (35) 

## k=1 Q

## ss (35) 

## Qk=2

def (35) 

## Qk:::1 ss (35)

The electrical powerinput for the unit operating at the intermediate compressor speed (k=v) and at the temperature (Tvh) is determined by:

k=i k=i**Ede,(Tvh)=Ede~35)**

### +M,,(Tvh-35) where:

# E~~r (62) f;k=1
ss

62



# - 47

Ek=2

def (35) 

## _Ek=2
ss

35 

# - 17 (47)

(17)

Ek=i (35) 

## k=1 (35)



## def Ess 

# = NE Ek=2 (35) 

## def Ek=1 ss (35)

The coefficient ofperformance. COPk=i(Tvh). at the intermediate speed (k=i) and temperature**T~b** canbe calculated by the equation:

- Similarly. coefficients ofperformance at temperature T,andT. can be calculated by the equations:' 

# X k=i Eder(35)= the electrical powerinput ofthe unit
at 35 ofdetermined at the intermediate
compressor speed (k=i) in the frost accumulation lest ME=s\ope ofthe electrical power input curve for the intermediate compressor speed (k=i)



## (1

- Nl::,)

where:

### Federal Register / Vol. 53. No. 49 / Monday. March 14. 1987 / Rules and Regulations 

### 8319

- <

T" ,=temperature at which the unit. operating Ht the minimum compressor speed. delivers capacity equal to the building load (Qk= '(T,)= BL(T3]J. found by equating the capacity equation Qk='(T j) (at Tj40'F) equal to the building load equation BL(T,) as identified in section 5.2.2 ofthis Appendix and solving for temperature 1\= temperature at which the unit. operating
at the maximum. delivers capacity equal
to the bUilding load (Qk=2(T,)=BL(T,)). found by setting the equation for capacity Qk=2(T j)eaual to the equation for building load BL(T j) from the twospeed procedure in section 5.2.2 and solving for temperature**COPk~1(T3)=the** coefficient ofperformance at the minimum compressor speed al temperature T3



## T2 2

D 

### 3 

## - T4

= T 2 2 vh 

## T4

B 

## COpk=2(T4)

= T4**COPk~2(T4)=the** coefficient ofperformance at the minimum compressor speed at temperature T. Qk='(T3)=steady-state capacity at the minimum compressor speed at temperature T3 • using equations for Qk=l(T j) from the two-speed procedure Qk-,,(T,)=steady-state capacity at the maximum compressor speed at temperature T" calculated using the equations**Q"~2(Tj)** ofthe two-speed procedure Ek -l(T3)=the electricalpower input at the minimum compressor speed at temperature T3
, calculated by using the equation for Ek='(Tj) (where TJ>40 OF) from the two-speed procedure in section 5.2.2 of this Appendix Ek=',(,l'.)=the electrical power input at the maximum compressor speed at temperature T., calculated by using the equation for Ek="(Tj) from the two-speed procedure in section 5.2.2 ofthis Appendix
The coefficient ofperformance.**COPk~V(Tjl,** shall be calculated by the following equation:**COPk~"(Tj)=A+BxTJ+CXTj2** where coefficients A,Band C shall be evaluated using the following**calculation~** step:



## C COpk=2(T4)

- COPk = 1 ( T 3 ) - B

# X(T4 - T3)

= 

## T2 4 

## T2 3

A 

## = COpk=2(T4) - B 

# * T

Case III

The compressor operates at the maximum speed (k=2) for which the building heating load, BL(TJ ), is greater than orequal to the heating capacity, Qs."=2(T j). 

### 4

Calculations shall be performed as prescribed for two-speed systems in Case IV of5.2.2 

# - c)(.**T~**

5.2.5. Heating seasonalperformancefacto]' used shall be the same as those used for unit fo]'split-type ductless systems. For split-type with the same type ofcompressor. ductless systems, HSPF shall be defined as * specified in section 5.2.1 ofthis Appendix. Separate values ofHSPF shall be determined [FR Doc. 88-5288 Filed 3-11-88; 8:45 am] for each corresponding combination set of BILLING CODE 64SG-Ol-M indoor coils used in the development ofSEER

as specified in section 5.1.7. The calculations