CAS-RM-79-102 COMMENT 12

-

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 
CAS-RM-79-102 COMMENT 12

.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 lor Central 

Air Conditioners, Including Heat 

Pumps 

AGENCY: Office of Conservation and 

Renewable Energy, DOK 

ACTION: Final rule. 

SUMMARY: The Department of Energy 

(DOE) hereby amends the test 

procedures for central air conditioners, 

including heat pumps. Test procedures 

are one part of the 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 

Conservation Act (NAECA). Among 

other program elements, the legislation 

requires that standard methods of 

testing be prescribed for covered 

products. 

The purpose of today's notice is to 

improve and refine the test procedure 

for central air conditions. including heat 

pumps. Specifically. DOE is expanding 

the coverage of the 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 

of Energy. Office of Conservation 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 

of Energy, Office of General Counsel. 

FOl'restal Building, Mail Station. GC12.1000 Independence Avenue SW .• 

Washington, DC 20585. (202) 586-9507. 

SUPPLEMENTARY INFORMATION:. 

a. Background 

The energy conservation pr.ogram for 

consumer products was established 

pursuant to Title II. Part D of the Energy 

Policy and Conservation Act (EPCA) 

(Pub. L. 94-163). Subsequently, EPCA 

was amended by the National Energy 

Conservation Policy Act (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 of the 

EPCA, as amended. requires that 

standard methods of testing be 

prescribed for covered products. 

including central air conditioners and 

heat pumps. Test procedures appear at 

10 CFR Part 430, Subpart D. 

Test procedures for evaluating the 

cooling performance of air-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 of air-source heat pumps as 

well as amendments to the test 

procedures for central air conditioners 

were issued by DOE on December 10, 

1979. 44 FR 76700, December 27, 1979. 

On March 15. 1985, DOE issued a Notice 

of Inquiry to solicit comments 

concerning a rating method for 

determining efficiency ratings for 

untested combinations of split-system 

central air conditioners in lieu of 

laboratory testing of such units. 50 FR 

13042, April 2. 1985. DOE published a 

proposed rule on October 3, 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 of the test procedures to 

address innovative designs, including 

split-type ductless systems and variablespeed central air conditioners. It also 

prescribes additional requirements for 

alternative rating methods for estimating 

efficiency ratings for untested 

combinations of split-system central air 

conditioners in lieu of laboratory testing, 

by defining the meaning of a coil family 

and establishing a requirement for test 

data to support the results. 

In.1981. DOE's Office of Hearings 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 test procedure 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 and Trane. The exceptions to 

Borg-Warner and York and waivers 

granted to Carrier and Trane by DOE 

will terminate on the effective date of 

today's rule. 

b. Discussion of Comments 

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. Continuous Air Test Method 

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 of Heating 

Refrigerating and Air Conditioning 

Engineers (ANSI/ ASHRAE) Standard 

116-1983 and Air Conditioning and 

Refrigeration Institute (ARI) Standard 

210/240-84. 

Eleven manufacturers and an industry 

trade association, the Air Conditioning 

and Refrigeration Institute (ARI), 

addressed the issue of the continuous 

air test method. 

Manufacturers agreed that the 

continuous air method would be a 

benefit, provided that DOE address 

certain concerns or problems. The 

manufacturers' primary concern was 

that the values for Seasonal Energy 

Efficiency Ratio (SEER) or Heating 

Seasonal Performance Factor (HSPF) 

rating for existing models of central 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. (Hereafter referred 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. 
CAS-RM-79-102 COMMENT 12

Federal Register I Vol. 53, No. 49 J Monday, March 14, 1987 I Rules and Regulations 8305 

during which the cooling or heating 

capability of the air conditioner or heat 

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 of a 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 of retrofitting 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 need or 

requirement to retest old models would 

add expense and impact negatively on 

manufacturer research and 

development. 

Also bearing on this issue are the 

provisions of the National Appliance 

Energy Conservation Act (NAECA) of 

1987, which require DOE to revise 

appropriately the energy conservation 

standard of a product when an amended 

test procedure would alter the measure 

of efficiency 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 air method with 

the six- and eight-method, or to retain 

the current damper method. The 

Department has evaluated the impacts 

each action would have on the industry 

and consumers, as well as the energy 

implications of each approach. 

DOE believes the adoption of the 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 of test 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 of the legislated 

minimum efficiency levels. Use of the 

current DOE test procedure will allow 

manufacturers to utilize their test 

facilities for research and development 

of new 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 of testing, the current method 

has achieved a level of familiarity, 

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 

of the 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 of Co. 

(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 of Standards (NBS) 

indicated a tendency for Co to differ 

between heating and cooling by 

approximately 0.1. This information 

indicates the average value ofthe 

heating Cn to 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 

testing with little increase in the 

accuracy of the ratings and may, in 

some cases, result in less accurate 

efficiency ratings. 

As a result of the comments and the 

review of the previous data collected, 

DOE has decided not to amend the 

heating degradation coefficient. The 

value will remain at its designed value 

of 0.25. 

3. Part Load Factor 

As part of the 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 of part load 

factor. These commenters agreed that 

DOE should not change the method of 

determination. Based on the analysis of 

l~ 

40 basic unit models of heat pumps and 

air conditioners, Carrier determined that 

the impact of an exponential versus 

linear part 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 

or HSPF 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 tha t the variance between the 

present straight line and the proposed 

exponential method will, in most cases. 

be absorbed in the rounding of the 

values. making the procedure change 

unnecessary. Therefore, DOE is not 

adopting the exponential method in 

today's final rule. 

4. Rating Procedure for Untested 

Combinations of Split-System Central 

Air Conditioners. 

The existing regulation for central air 

conditioners. including heat pumps, 

allows manufacturers of untested 

combinations of split-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 of rating 

untested combinations since each such 

rating method is unique and there is 

debate concerning the accuracy of any 

particular rating method. 

DOE proposed the adoption of a 

standard rating procedure for equipment 

combinations that are not laboratory 

tested in accordance with Appendix M. 

-Most commenters addressed the 

standard rating procedure for untested 

combinations of split-system central air 

conditioners. The majority of 

commenters favored the use of a 

standard method or a privately 

developed method (alternative method) 

when it can be verified to be more 

accurate than the standard method, as 

the desired procedure for rating 

equipment in lieu of laboratory testing. 

Six commenters favored a standard 

rating procedure. York, ARI. BARD and 

Carrier supported the use of the 

standard procedure 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 of utilizing a standard rating 

procedure was acceptable. Trante 

(Trane. No. 26, at 7) was concerned with 

the release or acquisition by other 
CAS-RM-79-102 COMMENT 12

8306 Federal Register I Vol. 53, No. 49 I Monday, March 14,1987 I Rules and Regulations ... I!ll2E 

manufacturers of proprietary 

information if a manufacturer's 

alternative. procedure was submitted to 

DOE because it was more accurate. 

Further comment was received 

concerning many of the components in a 

combination and the credit which 

manufacturers should receive in the 

calculations of the standard rating 

methodproposed by DOE. These 

components include fan delay, 

thermostatic expansion valves. solenoid 

valves. coil circuitry. and coil 

configuration. While the comments 

provided a diversity of opinion on these 

subjects. they did not present uniform 

solutions. Moreover. NBS' evaluation of 

these comments identified many areas 

of research required to resolve these 

issues. In view of the lack of consensus 

in the comments and NBS'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 standard rating procedure to 

be submitted to DOE for review. After 

review by DOE. it will be published as 

an National Bureau of Standards 

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 informa tion, 

computer codes, and other historical 

data that had been very costly to 

acquire and were concerned about 

release of possible 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; 

and Bard, No. 31, at 4). DOE believes 

that in these circumstances the 

consultant can submit the necessary 

documentation. with the proprietary 

information properly identified, directly 

to DOE. 

Rheem. an ARI 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, at 4). 

One commenter. not a member of ARt 

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 of the alternative 

method with calculated result. (Carrier. 

No. 40, at 8; Trane. No. 26, at 7; Addison, 

No. 43. at 4; Synder General, No. 41, at 

5). 

All manufacturer comments opposed 

submission of computer 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 computer codes 

and other proprietary data might be 

.made available to competitors. 

One commenter recommended that. 

for purposes of verification of the 

alternative method, results and test data 

should be provided for two condenser 

units, each with two different coils. This 

would require four sets of tests to verify 

the accuracy of the 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 of the alternative rating 

method. NBS believes that, at a 

minimum, this would require that the 

rating procedure be traceable to actual 

and complete test data. that complete 

documentation of the alternative method 

be provided, including the computer 

code when a computer model is used, 

and that all product-related information 

be included to allow for DOE ' 

verification of ratings submitted by the 

manufacturer. 

DOE agrees that the use of an 

alternative rating method is appropriate. 

if the alternative rating method is more 

accurate than a standardized rating 

method. The provision to allow the use 

of an alternative method of rating was 

included as part of DOE's 1979 central 

air conditioner final rule. Manufacturers 

arwrequired to conduct tests of sa·mples 

of the 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 defined by 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, Synder General. at 

12). 

This situation prompts 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 

resubmitted for DOE review and 

approval in order to maintain integrity 

in the. ratings. Consequently, 

manufacturers who previously 

submitted for use of an alternative 

method must resubmit such method to 

DOE and receive approval before 

continuing use of the alternative method 

for rating. central air conditioners_ The 

approval process is the same in 

structure to the current process. The 

purpose of DOE'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 of proprietary 

information. Under Title 10 CFR 1004.11, 

the sensitivity of proprietary 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 of information, 

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 of alternate rating 

methods, including that which is 

considered proprietary. e.g., computer 

codes, etc., to DOE for approval prior to 

the use of the ratings in today's rule. 

Several commenters stressed the need 

for accurate data on the various 

components of the system, inaccurate 

data or inappropriate assumptions could 

result in large 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, at 7). The First Company wanted 

information for the components to be 

made available by the manufacturer, 

whereas Trane opposed the divulging of 

information even to DOE. of what 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 standard rating 

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 
CAS-RM-79-102 COMMENT 12

Federal Register I Vol. 53, No. 49 I Monday, March 14, 1987 I Rules and Regulations 8307 

tolerance identified in § 430.23(mJ(1) as 

providing for a 90 percent confidence. 

with a true mean divided by 95 percent. 

(Trane. No. 26 at 7). Rheem sought the 

adoption of a 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. at 4). 

It is anticipated that publication of the 

standard rating method as an NBSIR. 

will enable manufacturers to use it as an 

alternative to testing or as the basis for 

an alternative rating method. DOE 

believes that development and 

publication of a standard method of 

rating combinations of condensers and 

coils will improve design, replacement 

selection and make DOE approval of 

alternative rating methods quick and 

easy. 

Several commenters addressed the 

definition of a coil family in discussing 

the requirement that test data 

supporting a manufacturer's alternative 

method include data for.two complete 

lines of coil 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. or horizontal) 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 of a 

given design (A-coils. air handlers, 

horizontal. counter flow or flat top coils) 

equipped with the same expansion 

device. Each family could cover a range 

of capacity from one to five tons. (York, 

No. 28. at 4). 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 of coils with the 

same basic design features that affect 

the heat exchanger performance. Those 

features which identify a coil family are: (i) Basic configuration (A-shape. Vshape. slanted or flat 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 of coils 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 of alternative 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 Water Source Heat Pump and 

Earth Coupled Heat Pumps 

Several commenters maintained that 

there is no need for a test procedure for 

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 of this test pl'Ocedure, with 

limited changes, would have allowed 

consumers to compare the ground 

water-source, earth-coupled. and air 

source centra! air conditioners or heat 

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-coupled heat 

pumps from the category of central 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 multi zoning. 

(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 of a 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 of the 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 test procedure considers the 

ability to zone as a utility similar to air 

conditioners with setback thermostats. 

Zoning is a consumer preference. not an 

efficiency improvement. Therefore. the 

efficiency of the system is analyzed as a 

single zone. The requirements of rating 

by test or alternative method of various 

combinations of indoor coils with a 

single outdoor unit are covered under 

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 outdoor units 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 of the damper method 

for testing requires that changes be 

made to the p'roposed test procedure to 

allow coverage of split-type ductless 

systems. These changes are required 

due to the deletion of the incorporation 

of ANSI/ 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 power will be 

the compressor "cut-on" to indoor fan 

"cut-off' time. The fan power for 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 of the ductless system will require 

the addition of plenums on the outlets to 

allow for the measurement of air flow 

and the capacity of the system. 

7. Demand Defrost 

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 

enhancement factor to be applied as a 
CAS-RM-79-102 COMMENT 12

8308 Federal Register I Vol. 53, No. 49 I Monday. March 14, 1987 I Rules and Regulations 

multiplier directly to HSPF. The 

multiplier has a maximum value of 1.04 

which is varied between 1.04 and 1.00 

for single-speed, two-speed and 

variable-speed systems based on the 

length of time between defrost. 

ARI and Snyder General 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 but did not 

give any alternative suggestion. 

(Lennox, No. 35, at 5). . 

York commented that the proposed 

procedure fails to recognize the use of 

auxiliary head during 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 heat pump will 

run a much longer time in the field 

between defrosts than during the frost 

accumulations test. Correcting for the 

reduced frequency of defrosts with drier 

weather increased the span of titne 

between defrosts by a factor of 2.8 (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 

would require 19.6 percent more power 

than a demand defrost system at this 

condition. York concluded by proposing 

that the seven percent enhancement 

value for demand control systems be 

~etained. If any changes are made. York 

supports the enhancement that would 

have a increased value with increased 

span time between defrosts. (York, No. 

28. at 3). 

Carrier pointed out that the 

enhancement credit for variable-speed 

systems is inconsistent with that 

prescribed for single-speed systems. 

(Carrier. No. 40, at 11). Carrier stated 

that the amount of credit given for a 

demand defrost control should be based 

on the ratio of the 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 +0.04 X (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=lesser of 720 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. at 4). 

However. Trane pointed out a lack of 

consistency in the time between defrost 

terminations for different units of the 

same model, and commented that the 

proposed correlation. being very 

sensitive to this time, may provide 

significantly different values of the 

damand defrost credit during the rating 

verification process. In connection with 

this observation. Trane suggested 

another form of the equation for the 

demand defrost credit: 

Fd=1.03 +0:03 x [(90-Tte,tl!630J 

DOE recognizes that frosting/ 

defrosting of a heat pump is a very 

complex phenomenon governed by 

system design and controls, operating 

conditions and sizing. System 

performance degradation in the frosting 

region is related to three basic penalties: 

1. Degradation of performance due to 

frosting itself; formation of frost on the 

outdoor coil reduces system 

instantaneous capacity. and reduces 

system instantaneous COP. 

2. Decrease of average capacity due to 

the need to perform defrosting of the 

outdoor coil. The time used by a system 

to defrost is subtracting from the time 

that would be used for heating. thus 

reducing system ability to supply heat. 

In addition. negative capacity 

(additional load) is introduced to the 

house. 

3. Use of tempering heat above the 

balance point. Since delivery of cold air 

to the conditioned space would not be 

acceptable, an electric heater is used to 

temper heat pump negative capacity. If 

defrost occurs above the balance point, 

use of the electric heat degrades system 

seasonal efficiency. 

DOE agrees that different heat pumps 

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 not include 

frosting/defrosting below 17°F outdoor 

temperature even for time defrost 

controlled systems, (penalty no. 1 and 

2.) Consequently. system capacity 

prescribed in the procedure is 

optimistically high (approx. 3-5 percent) 

for time-defrost heat pumps. • The procedure does not take into 

account heat tempering above the 

balance point (penalty no. 3.) 

A review of the comments on demand 

defrost credit show that manufacturers 

do not have a clear understanding of the 

objective of the demand defrost credit. 

DOE believes that demand defrost credit 

should be applied as compensation for 

improved performance not measured 

during the defrost test because of high 

humidity specification, and that 

frosting/defrosting is too complex for 

attempts to describe all three penalties 

by one correlation. The present 

procedure takes into account 

performance degradation due to frosting 

of the outdoor coil (penalty no. 1) 

through a testat 35 OF outdoor 

temperature. In order to shorten the 

defrost test. high outdoor humidity 

conditions. more severe than average in 

the field. were prescribed. During this 

test a system with demand defrost may 

not show its full performance potentital. 

If the time between defrosts is the 

same for this unit as if equipped with a time controlled defrost, a credit is in 

order for the system because full sustem 

performance ability in field conditions 

was not measured during the test. On 

the other hand. if a system with a 

demand defrost control does not go into 

defrost at all during the 35 OF test. no 

extra credit should be given to the unit 

because the test accounted (on a relative basis) for the full performance 

potential of the tested unit. Systems 

equipped with demand defrost, that 

defrost during testing but after the 

period allotted to time controlled defrost 

systems, should receive a credit based 

on a prorated value of the actual defrost 

time versus the duration of the defrost 

test. 

As a result of the review of the 

industry comments and performance 

data collected for ten various models 

with demand defrost. NBS 

recommended a revised formula for 

crediting demand defrost. 

1"8=1 +0.03 X (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, whichever is greater 

Tmax = maximum time between defrosts 

allowed by controls in minutes 

or 

no. whichever is smaller 

The correlation provides three percent 

credit for a system with demand defrost 

which has 90 minutes or less time 

between defrost terminations during the 

frost accumulation test. The amount of 

credit is linearly prorated to zero for 

longer time spans between defrosts. A 

value of zero is attained if the test time 

reaches the maximum compressor time 

allowed by its controls or maximum 

time prescribed by the procedure (720 
CAS-RM-79-102 COMMENT 12

Federal Register I Vol. 53. No. 49 I Monday. March 14. 1987 I Rules and Regulations 8309 

minutes). The value of the maximum 

credit (three percent) was chosen based 

on review of the HSPF values of ten 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 

capacity correction at the DHRmin in 

region IV. The seven percent capacity 

correction resulted 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 of the 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 of variablespeed units. and outlined the basis for 

such a test. (KeepRite. No. 33. at 1). 

KeepRite also recommended that 

systems with automatic controls and 

manual controls be differentiated. At 

this time. DOE does not believe there is 

a need for a procedure to test -variablespeed systems for load matching ability. 

The test. as outlined by KeepRite, 

appears difficult to prescribe and 

burdensome to conduct. Regarding 

differentiation between manual 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 not justified. 

KeepRite commented that additional 

test points are needed at different 

intermediate speeds to more accurately 

represent the performance of variablespeed units. (KeepRite. No. 33. at 2). 

Trane showed that increasing the 

number of intermediate test pointsimproves SEER of the tested unit. 

According to Trane. the impact of the 

number of test points is most significant 

for the unit of the highest maximum 

speed to minimum speed ratio. For this 

ratio having the value of 3.5. the 

addition of the first intermediate speed 

test (to the single-speed procedure) 

improved the SEER by 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 an improvement of 

approximately 0.8 percent. (Trane, No. 

26. at 16). -

Since additional improvement to the 

SEER rated value decreases 

significantly with additional 

intermediate test points. 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 operation in the 

intermediate speed region. The DOE 

proposal used linear interpolation of the 

power input between 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: 

-Perform interpolation using EER or 

COP values and then derive the 

energy input by dividing capacity by 

EER or COP; 

-Perform parabolic interpolation. 

The advantage of this approach 

allows for the interpolation of EER 

(COP) versus interpolation of energy 

input. 

The procedure relies on three 

performance points for evaluation of the 

unit performance in the intermediate 

speed operation range. The three points 

are: 

-Maximum speed balance point (the 

intersection point between the 

building load line and the heat pump 

capacity line at the maximum speed); 

-Minimum speed balance point (the 

intersection point between the 

building load line and the heat pump 

capacity line at the minimum speed); 

and 

-Intermediate speed point (the 

intersection point between the 

building load line and the heat pump 

capacity line at the intermediate 

speed at which the unit was tested at 

87°F temperature). 

At these three points the unit capacity 

and power are known. To evaluate 

power NBS recommended obtaining 

power in the intermediate speed region 

through evaluating EER (COP) at the 

three points, interpolating EER (COP) at 

required temperature bins. and using the 

building loads at these temperatures and 

EERs (COPs). 

NBS explained that since the capacity 

line. i.e., the building load line. is 

straight. the power line could also be a 

straight line if EER were independent of 

temperature. If EER was prescribed by a 

linear equation, the power line equation 

will be of a higher order. Thus the 

complexity of the power line is affected 

by the complexity of the EER line, with 

the power line always more complex. 

NBS recommends the parabolic 

interpolation for two reasons: 

-Unlike the power line. the EER (COP) 

line in the intermediate speed region 

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 of the 

second or higher order. Although 

different systems may have different 

characteristics. a parabolic fit should 

give the best estimation of the EER 

line with three data points as input. 

Trane commented that the 

intermediate speed test should be run at 

a speed one-third of the 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 and minimum speed in the cooling 

mode. 

Carrier commented that the 

intermediate speed test should not be 

fixed. but rather be specified in terms of 

minimum and maximum compressor 

speeds and respective capacities. 

(Carrier. No. 40, at 11.) 

Lennox commented that the 

compressor speed at the intermediate 

speed test should be "tied down" better. 

perhaps in terms of inverter frequency. 

(Lennox. No. 35, at 4.) Carrier supported 

the proposed intermediate speed 

tolerance of plus or minus 10 percent. 

Trane considered this tolerance to be 

wide and suggested narrowing it to plus 

or minus 5 percent. York commented 

that system capacity at Tout=47°F used 

for calculation of the minimum and 

maximum DHR should be obtained at 

the compressor speed corresponding to 

maximum speed in the cooling mode. 

DOE found that the speed for the 

intermediate speed test proposed in the 

proposed rule (average between the 

maximum and minimum compressor 

speeds) results in a capacity 

significantly greater than the building 

load at 87°F. Two commenters stated 

that description of the speed being onethird between the maximum speed and 

the minimum speed provides a 

reasonable estimate of the proper speed 

for the intermediate speed test. DOE 

also concurred with the need to identify 

the intermediate speed precisely to 

creatl! repeatable tests .. For-this reason 

the intermediate speed is identified in 

terms of inverter frequency with a 

tolerance of plus 5 percent or the 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) 
CAS-RM-79-102 COMMENT 12

8310 Federal.Register J Vol. 53, No. 49 I Monday, March 14,'1987 I Rules and. Regulations 

It was suggested that 12 minutes on- time should be allowed only if the 

minimum speed is half the maximum 

speed. The off-time should be 18 minutes 

to reflect the decrease off-time variablespeed systems should provide. (Lennox, 

No. 35, at 4.) York commented that 

compressor on-time should be increased 

for variable-speed units but this 

increase should not be set arbitrarily to 

12 minutes; the amount of increase 

should depend on the maximum to 

minimum capacity ratio. (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~ could be 

evaluated by the equations: 

Ton=6 minxQmax/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 

greater capacity modulation capability. 

NBS presented data for which a system 

with capacity modulation ratio of two, 

the penalty is less that five percent, 

while for a system with capacity 

modulation ratio of three, 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, and 48 minutes off). Today's 

rule includes DOE's determination of the 

following cycle times for variable-speed 

units for both cooling and heating Ton is 

12 minutes and Torr 48 minutes in order 

to retain the 20 percent on-time used in 

the single speed system procedure. . Trane suggested adding an optional 

nominal capacity test to allow the 

ratings to reflect energy savings of ' 

systems in which the maximum speed in 

the heating mode is greater than 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 this test in today's rule as an 

optional test to be included for 

manufacturers with units 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 of the 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 if DOE decided to retain the 

damper test method. 

DOE, in its decision to retain the 

damper method, has concluded that fan 

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 if HSPF 

calculations are performed for the 

maximum design heating requirement, 

the procedure will underestimate energy 

input to the electric heater, 

overestimating the effic:iency descriptor 

because the intersection point 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 of ten percent for 

capacity and 1.5 percent for power. 

These factors were selected after a review of test data of heat pumps 

equipped with demand defrost controls. 

NBS further recommended the tolerance 

for power measurement of 0.5 percent be 

maintained for variable-speed systems. 

DOE evaluated the NBS comments on the capacity and energy input lines for 

determining HSPF and agrees tha t the 

method is sound. Therefore, the 

variable-speed procedure includes 

degradation due to frost accumulation at 

the maximum speed. The capacity and 

power of a variable-speed system at the 

maximum speed will be evaluated based on performance at 17 OF, .47 OF aHd 35 OF 

outdoor temperatures. The NBS 

equntions are includedin today's 

rulemaking. ' 

9. Transition Period 

Several commenters expressed 

concern with the impact of the effective 

date of the new procedures and any 

transition period. Since these comments 

addressed the implementation of a new 

test procedure for single speed and twospeed units other than the damper 

method, DOE has decided that these 

concerns have been resolved 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 not necessary. 

The amendments for new models will 

be effective 180 days after publication in 

the Federal Register. 

During the period between publication 

and effe.ctive date, all manufacturers 

using an alternative method to rate 

untested combinations of central air 

conditioners or heat pumps 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 or use testing to rate 

the equipment. Submittals of alternative 

rating methods should be made within 

three months of publication oftoday's 

rulemaking in order for review and 

approval to be assured by the effective 

date of this amendment. Those 

manufacturers not receiving approval 

prior to the effective date, must submit a 

written request to DOE for an extension. 

c. Procedural Matters 

1. Test Procedures. The test 

procedures for central air conditioners 

prescribed today are included in 

Subpart B of Part 430 and are 

substantially the same a.s those 

eSlaLlished in the existing procedures 

with the exception of the changes 

discussed above. Appendix M of 

Subpart B provides test procedures for 

those models of central air conditioners 

currently requiring waivers. The 

changes to appendix M of Subpart B do 

not incorporate the ASHRAE and ARI 

commercial standards contained in the 

proposed rulemaking, thus the 

requirements of the Federal Energy 

Administration Act do not apply. 

2. General PrOllisions. Today's 

rulemaking contains the definitions of 

"central air conditioner," and "heat 

pump" as identified,in NAECA and 

DOE's definition of a "coil family." 

3. Application of Test Procedures. The 

test procedures prescribed today 

address variable-speed systems and 

split-type ductless systems. The revision 

of the demand defrost credit in today's 

notice applies to all system types. The new procedures will provide ratings 

comparable to those ratings already 

received pursuant to granted waiver test 

procedures. The compatibility of the 

new rating procedures with those 

established in prior rule makings creates 

no conflict with the conservation 

standards established by NAECA. 

d. Environmental Review 

Pursuant to section 7(c)(2) of the 

Federal Energy Administration Act of 

1974, DOE submitted a copy of this 

notice to the Administrator of the 

Environmental Protection Agency on 

January 29, 1987, for his comments 
CAS-RM-79-102 COMMENT 12

Federal Register / Vol. 53, No. 49 / Monday, March 14, 1987 / Rules and Regulations 8311 

concerning the impact of this proposal 

on the quality of the environment. A 

response. dated April 6. 1987, was 

received expressing support of the 

rulemaking. 

Since test procedures under the 

energy conservation program for 

consumer products will be used only to 

standardize the measurement of energy 

usage. and will not affect the quality of 

distribution of energy 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 

of the human environment within the 

meaning of the National Environment 

Policy Act of 1969. Consequently. 

neither an Environmental Impact 

Statement nor an Environmental 

Assessment is required for the final rule. 

e. Review Under Executive 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. or on State and 

local governments. The Executive Order 

also requires that regulatory impact 

analyses be prepared for "major rules." 

The Executive Order defines "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 or prices 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 of the 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. or government 

entity by the amendment of existent 

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 agency prepare an initial regulatory 

flexibility analysis to be published at 

the time the final rule is published. This 

requirement (which appears in section 

603) does not apply if the agency 

"certifies that the rule will not, if 

promulgated. have a significant 

economic impact on a substantial 

number of small entities." The final rule 

affects manufacturers of central 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 of any 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 

substantiar number 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 of Energy 

Organization Act. Pub. L. 95-91J. 

List of Subjects in 10 CFR Part 430 

Administrative practice and 

procedures. Energy conservation. 

Household appliances. 

In consideration of the foregoing, Part 

430 of Chapter II of Title 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, 

Assistant Secretary. Conservation Gild 

Ilenewable Energy. 

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 "Heat pump" and 

auding the definition of a "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 of which is 

above 225.000 Btu per hour, and is a heat 

pump or a cooling only unit. 

"Heat pump" means a product. other 

than a packaged terminal heat pump, 

which consists of one 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 air heat exchanger to provide 

air heating. and may also provide air 

cooling. dehumidifying. humidifying 

circulating. and air cleaning. 

"Coil family" means a group of coils 

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 of coils 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) CentaJ Air Conditioners. (1) The 

estimated annual operating cost for 

cool1ng-only units and air-source heu t 

pumps shall be one of the 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 of the 

cooling capacity. in Btu's per hour. 

determined from the steauy-state wetcoil test (Test A) measured at the 

highest compressor speed, as describeu 

in section 3.1 of Appendix M to this 

subpart. divided by the seasonal energy 

efficiency ratio, in Btu's per watt-hour. 

determined from section 5.1 of Appentlix 

M to this subpart; (B) the representative 

average use cycle for cooling of 1.000 

hours per year; (C) a conversion factor 

of 0.001 kilowatt per watt; and (D) the 

representative average unit cost of 

electricity in dollars per kilowatt-hour 

as provided pursuant to section 323(b)(2) 

of the Act, the resulting product then 

being rounded off to the nearest dollar 

per year; 

(ii) For air-source heat pumps which 

provide only heating or the heating 

portion of the estimated annual 

operating cost for air-source heat pumps 

which provide both heating and cooling. 

the product of: (A) The quotient of the 
CAS-RM-79-102 COMMENT 12

8312 Federal Register I Vol. 53, No. 49 I Monday, March 14, 1987 I Rules .and Regulations 

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 of Appendix M to this 

subpart, divided by the heating seasonal 

performance factor, in Btu's per watthour, calculated for heating region IV 

corresponding to the above mentioned 

standardized design heating requirement 

determined from section 5.2 of Appendix 

M to this subpart; (B) the representative 

average use cycle for heating of 2,080 

hours per year; (C) the adjustment factor 

of 0.77 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 of 0.001 kilowatt 

per watt; and (E) the representative 

average unit cost of electricity in dollars 

per kilowatt-hour as provided pursuant 

to section 323(b)(2) of the 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 of the quantity determined in 

paragraph (m)(l)(i) of this section added 

to the quantity determined in paragraph 

(m)(l)(ii) of this 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 of the estimated regional 

annual operating cost for air-source heat 

pumps which provide both heating and 

cooling, the product of: (A) The quotient 

of the 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 of Appendix M to this 

subpart, divided by the seasonal energy 

efficiency ratio, in Btu's per watt-hour, 

determined from section 5.1 of Appendix 

M to this subpart; (B) the estimated 

number of regional cooling load hours 

per year determined from section 6.1.3 of 

Appendix M to this subpart; (C) a 

conversion factor of 0.001 kilowatts per 

watt; and (D) the representative average 

unit cost of electricity in dollars per 

kilowatt-hour as provided pursuant to 

section 323(b)(2) of the Act, the resulting 

product then being rounded off to the 

nearest dollar per year; 

(ii) For air-source heat pumps which 

provide only heating or the heating 

portion of the estimated regional annual 

operating cost for air-source heat pumps 

which provide both heating and cooling, 

the product of: (A) The quotient of the 

standardized design heating 

requirement, in Btu's per hour, nearest to 

the canacitv measured in the high 

temperature test (Test A), determined in 

sections 5.2 and 6.2.6 of Appendix M to 

this subpart, divided by the heating 

seasonal performance factor, in Btu's 

per watt-hour, calculated for the 

appropriate region of interest and 

corresponding to the above mentioned 

standardized design heating requirement 

determined from section 5.2 of Appendix 

M to this subpart; (B) the estimated 

number of regional heating load hours 

per year determined from section 6.2.5 of 

Appendix M to this subpart; (C) the 

adjustment factor of 0.77 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 of 0.001 

kilowatts per watt; and (El the 

representative average unit cost of 

electricity in dollars per kilowatt-hour 

as provided pursuant to section 323(b)(2) 

of the 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 regional annual operating cost 

is the sum of the quantity determined in 

paragraph (m)(3)(i) of this section added 

to the quantity determined in paragraph 

(m)(3)(ii) of this section. 

(3) The measurers) of efficiency for 

cooling-only units and air-source heat 

pumps shall be one or more of the 

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 per watt-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 per watt-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 off to 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 per watthour, determined according to section 

5.3 of Appendix M to this subpart for 

each standardized design heating 

requirement within each climatic region, 

rounded off to the nearest 0.05. 

(4) Other useful measures of energy 

consumption for central air conditioners' 

shall be those measures of energy 

consumption which the Secretary of 

Energy determines are likely to assist 

consumers in making purchasing 

decisions and which are derived from 

the application of Appendix M to this 

subpart. 

(5) After September 12,1988, all 

measures of energy 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. Section 430.23 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) of this section shall 

be that combination manufactured by 

the condensing unit manufacturer likely 

to have the largest volume of retail 

sales. Components of similar design may 

be substituted without requiring 

additional testing if the represented 

measures of energy consumption 

continue to satisfy the applicable 

sampling provisions of paragraphs 

(m)(l)(i) and (m)(l)(ii) of this section. For 

every other condenser-evaporator coil 

combination manufactured by the same 

manufacturer or in part by a component 

manufacturer using that same 

condensing unit, either-

(i) A sample of sufficient size, 

comprised of production units or 

representing production units, shall be 

tested to ensure that the requirements of 

paragraphs (m)(l)(i) and (m)(l)(ii) of this 

section are met for such other 

condenser-evaporator coil 

combinations; or 

(ii) The representative values of the 

measures of energy consumption shall 

be based on an alternative rating 

method that has been approved by DOE 

in accordance with the provisions of 

paragraphs (m)(4) and (m)(5) of this 

section. 

(3) Whenever the representative 

values of the measures of energy 

consumption, as determined by the 

provisions of paragraph (m)(2)(ii) ofthis 

section, do not agree within five percent 

of the representative values of the 

measures of energy consumption as 

determined by actual testing, the 

representative values determined by 

actual testing shall be used to comply 

with section 323(c) of the Act, or to 

comply with rules prescribed under 

section 324 of the Act. 

(4) The basis of the alternative rating 

method referred to in paragraph 

(m}(2)(ii) of this section shall be a 
CAS-RM-79-102 COMMENT 12

Federal Register / Vol. 53, No. 49 t Monday, March 14, 1987 / Rules and Regulations 8313 

representation of the test data and 

calculations of a mechanical vapor 

compression refrigeration cycle. The 

major components in the refrigeration 

cycle shall be modeled as "fits" to 

manufacturer performance data or by 

graphic or tabular performance data. 

Heat transfer characteristics of coils 

IlIay be modeled as a function of face 

area, number of rows, fins per inch, 

refrigerant circuitry, air flow 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 indoor fan and degradation 

coefficient. 

(5) Manufacturers who elect to use an 

alternative rating method for 

determining measures of energy 

consumption under paragraphs (m)(2)(ii) 

and (m)(4) of this section must submit a 

request to DOE for reviewing the 

alternative rating method to the 

Assistant Secretary of Conservation and 

Renewable Energy, 1000 Independence 

Avenue, SW., Washington, DC 20585, 

and receive approval to use the 

alternative method by the Assistant 

Secretary before 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 of the official representing the 

manufacturer. 

(ii) Complete documentation of the 

alternative rating procedure, including 

the computer code 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 

condensing units shall differ by at least 

a factor of two. 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 of energy 

consumption under paragraphs (m)(2)(ii) 

and (m)(4) of this section must either 

subject a sample of their units to 

independent testing on a regular basis, 

e.g., voluntary certification program, or 

have the representations reviewed and 

certified by an independent stateregistered professional engineer who is 

not an employee of the manufacturer. 

The registered professional engineer is 

to certify that the results of the 

alternative rating procedure accurately 

represent the energy consumption of the 

unites). The manufacturer is to keep the 

registered professional engineer'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 M to Subpart B of Part 

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 "For units 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 of section 4.1.1.2. adding one 

sentence at the end of 4.2.1.2 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(or air source cooling 

only units. 

* * * 

2.1.5 Testing required for units with 

triple-capacity compressors. [Reserved) 

2.1.6 Testing required for units with 

variable-speed compressors. The tests for 

variable-speed equipment consist of five (5) 

wet coil tests and two (2) dry coil tests. Two 

of the 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 if the coefficient of degradation (CD) 

value of 0.25 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 required for split-type 

ductless systems. The tests for split-type 

ductless systems are determined by the type 

of compressor installed in the outdoor unit. 

Por the appropriate tests refer to sections 

2.1.1, 2.1.2, 2.1.3, 2.1.4, 2.1.5. or 2.1.6 of this 

Appendix. 

2.2 Testing required for ail' source heating 

only units. 

* 

2.2.3 Testing required fol' units with 

triple-capacity compressors. (Reserved) 

2.2.4 Testing required for units with 

variable-speed compressors. 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 of the maximum speed frost 

accumulation test. two equations are 

provided in section 4.2 of this 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, of this Appendix. 

2.2.5 Testing required for split-type 

dudless system. The type of compressor 

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 conditions for air source 

cooling only units. 

3.1.5 Testing conditions for units with 

triple-capacity compressors. (Reserved) 

3.1.6 Additional testing conditions for 

cooling-only units with variable-speed 

compressors. Por cooling-only units and airsource heat pumps with va raible-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 of the 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 conditions for steady-state 

wet coil tests. Tests A and B shall be 

performed at the maximum speed at 

conditions specified in section 3.1.1 of this 

Appendix. Test 8. and the low temperature 

test are performed at the minimum speed 

with outdoor dry bulb temperatures of 82"P 

and 67"P respectively. The intermediate 

speed wet coil test is performed at the 

outdoor dry bulb temperature of 87'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 of this 

Appendix. 

3.1.6.2 Test conditions for dry coil tests. 

Dry coil Tests C and D are conducted at an 

outdoor dry bulb temperature of 67'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 of 57"P or less 

be used). 
CAS-RM-79-102 COMMENT 12

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 of interconnecting 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 of tubing 

furnished, or with 25 feet of tubing, 

whichever is greater. At least 10 feet of the 

interconnection tubing shall be exposed to 

the outside conditions. The line sizes, 

insulation and details of installation shall be 

in accordance with the manufacturer's 

published recommendation. 

3.1.7.2 Control testing conditions for 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 or multiple discharge outlets 

shall have short plenums attached to 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 enter the common duct section for 

the purpose of equalizing the static pressures 

in each plenum. The length of the plenum is a 

minimum of 2.5x(AXB)·5. A=width and 

B= height of duct or outlet. Static pressure 

readings are taken at a distance of 

2X(AxBj,5from the outlet. 

3.2 Testing conditions for air source 

heating only units. 

* * 

3.2.3 Testing conditions for units with 

triple-capacity compressors. (Reserved) 

3.2.4 Testing conditions for units with 

variable-speed compressors. The testing 

condition for variable-speed compressors 

shall be the same as those for single speed 

units as described in section 3.2.1 of this 

Appendix with the following exceptions; the 

cyclic test is performed with an outdoor dry 

bulb temperature of 62°F and a wet bulb 

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 conditions for split-type 

ductless system. The testing conditions for 

split-type ductless systems shall be based on 

the type of compressor installed in the single 

outdoor unit. The heating mode shall have the 

same piping and control requirements as in 

3.1.7. 

4.1 Test procedures for 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 of 12 minutes or the "on" time as 

extended by fan delay, if so equipped. The 

electrical energy shall be measured for the 

total integration time (8e• e) of 60 minutes. In 

lieu of conducting C and D tests, an assigned 

value of 0.25 shall be used for the 

degrada lion coefficient for cooling, Co. 

4.1.1.3 Testing procedures for triplecapacity compressors. (Reserved) 

4.1.1.4 Intermediate cooling steady-state 

test for 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 of the 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 of the 

cooling mode. (Inter. speed=min. speed+ 1/3 

(max. speed-min. speed.) A tolerance of plus 

five percent or the next higher inverter 

frequency step from that calculated is 

allowed. 

4.1.1.5 Testing procedures for split-type 

ductless systems. Cyclic tests of ductless 

units will be conducted without dampers. The 

data cycle shall be preceded by a minimum 

of two cycles in which the indoor fan cycles 

on and off with the compressor. For the data 

cycle the indoor fan will opera te 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-off time. The fan power for 

three minutes after compressor cut-off shall 

be added to the integrated cooling capacity. 

4.2 Testing procedures for 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 section 4.1.1.2 of this 

Appendix. Cyclic tests of split-type ductless 

units will be conducted without dampers, and 

the data cycle shall be preceded by a 

minimum of two cycles in which the indoor 

fan cycles on and off with 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 

off during 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 section 4.1.1.4 of this 

Appendix. The following two equations may 

be used in lieu of the 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 
CAS-RM-79-102 COMMENT 12

Federal Register / Vol. 53, No. 49 / Monday, March 14, 1987 / Rules and Regulations 8315 

* 

5.1.5 Seasonal energy efficiency ratio for 

air-source units with triple-capacity 

compressors. (Reserved) 

5.1.6 Seasonal energy efficiency ratio for 

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(T j) 

N 

E (T j) 

where the number of hours in the ith 

temperature bin (nj)/N is defined in Table 

6.1.2 of this Appendix. 

The SEER shall be determined by 

evaluating three cases of the compressor 

opera lion. Case I is the same as specified in 

5.1.3.1 with the exception that the quantities 

QSl=l(T;) and Essk=l(Tj) 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) speed between the 

maximum (k=2) and minimum (k=l) speeds 

to satisfy the building cooling load. Evaluate 

the following equations: 

k=v QSS (Tj ) =BL(T.) ] 

= Q~~v (Tj ) X nj 

N 

where Esl=V(T;) the electrical power input 

required by the unit to deliver capacity 

matching the building load at 

temperature TJ• 

82 67 J 

where Qssk=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 Tj and 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 of the unit at any 

temperature Tj when the compressor operates 

at the intermediate speed (k=i) may be 

determined by: 

Where: 

QSSk=i(87) = the capacity of the unit at 87 QF 

determined by the intermediate cooling 

steady-state test. 

MQ=slope of the capacity curve for the 

intermediate compressor speed (k=i) 

~ Oks=s2( 95 l - Qk=2(B2l 

+ N " ss Q 95 - 82 

Once the equation for Q • ."=i(T j) has been 

determined, the temperature where Q • ."=i(Tj) 

=BL(Tj) can be 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 determined by: 

where: 
CAS-RM-79-102 COMMENT 12

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

E"k=i(87)=the electrical power input of the 

unit at 87'F determined by the 

intermediate cooling steady-state test 

ME=scope of the electrical power input 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 of the unit. 

EER •• (Tvcl. at the intermediate speed (k=i) 

and temperature Tvc can be calculated by the 

equation: 

k=i 

k- i Qss (Tvc) 

EER - (T ) =------ ss vc 

Similarly. energy efficiency ratios at 

temperatures Tl and T. can be calculated by 

the equations: 

where: 

Qk=2(T ) 

ss 2 

Ek=2(T ) ss 2 

T. = temperature at which 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 (Tj)) 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 (T2)). found by 

equating the capacity equation [(Q.,k=2 

(Tj)] 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 at the minimum 

compressor speed at temperature 1\. 

EERssk="{T2}=the steady state energy 

efficiency ratio at the maximum 

compressor speed at temperature 1'2. 

Essk=I(Til=the electrical power input at the 

minimum compressor speed at 

temperature T •• calculated by the 

equation in section 5.1.3. 

Es,k=,,{T2 } = the electrical power input at the 

maximum compressor speed at 

temperature T2• calculated by the 

equation in section 5.1.3. 

The energy efficiency ratio. EER •• k=v(Tj}. 

shall be calculated by the following equation: 

where coefficients A. B. and C shall be 

evaluated using 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 III is the same as specified in 5.1.3.4. 

The quantities Q .. k='(Tj) and E .. k="{Tj) and 

E .. k="{Tj) shall be calculated by the equations 

prescribed in 5.1.3. 

5.1.7 Seasonal energy efficiency ration for 

split-type ductless systems. For split-type 

ductless systems. SEER shall be defined as 

specified in section 5.1.1 of this Appendix for 

each combination set of indoor coils to be 

used with a common outdoor unit. 

T2 

1 

T2 

2 

-B)(T2 -CX T2 

2 

5.2' •• 

For air-source units that are equipped with 

"demand defrost control systems". the ,value 

for HSPF. as determined above shall be 

multiplied by an enhancement factor Fd.! to 

compensate for improved performance not 

measured in the Frost Accumulation Test. 

The factor. Fde! depends on the number of 

defrost cycles in a 12-hour period and should 

be calculated as follows: 

F det~l +0.03 X (1-(T test -90)/(T max-90)) 

where: 

Fder=demand defrost credit (used as a' 

multiplier to HSPF) 

T, •• t=time between defrost terminations in 

minutes or 90. (whichever is greater) 
CAS-RM-79-102 COMMENT 12

Federal Register / Vol. 53, No. 49 / Monday, March 14, 1987 / Rules and Regulations 8317 

Tm .. =maximum time between defrosts 

-allowed by controls. (in minutes or 720 

(whichever is les~) 

HSPF = 

5.2.3 Heating seasollal perfol1nance 

factor for air-source units with triplecapacity compressors. (Reserved) 

5.2.4 Heating seasonal pelforlIloilce 

factor for units with variable-speed 

L:' n· J BL (T j) J N 

(Lj 

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 and DHRma" 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 of the maximum speed capacity, 

Qssk~"(47), in the prescribed equations if the 

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 of HSPF, three cases are 

considered, the quantities E (TIN;) and 

RH(T/Nj ) shall be calculated depending on 

compressor mode of operation. 

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(T j) = Qk=v (T j) X nj 

N N 

where: 

Qk=V(T.} 

- J 

3.413 Xcopk=V(T j ) 

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. Ess k= '0:;). shall be 

calculated by the following equeations: 

(T .-47) 

J 

(T . -4 7) 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 power input required 

by the unit at temperature Tj to deliver 

capacity matching the building load 

COPk='(T;)=the coefficient of performance at 

which the unit delivers capacity 

matching the building load at 

temperature Tj 

Defore the coefficient of performance. 

COPk=V(Tj), 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 of the unit at any temperature T 

when compressor operates at the 
CAS-RM-79-102 COMMENT 12

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 of the capacity curve for the 

intermediate compressor speed [k=i) 

(62 ) Qk=1 Q (47) ss ss 

MQ = )( (1 - NQ) 

+ NQ 

NQ = 

Once the equation for Qk=i[Tj) 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 Qss (17 ) 

35 17 

k= i 

Qdef (35 ) k=1 Qss (35 ) 

Qk=2 def (35) Qk:::1 ss (35 ) 

The electrical power input 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 of performance. 

COPk=i(Tvh). at the intermediate speed (k=i) 

and temperature T~b can be calculated by the 

equation: -

Similarly. coefficients of performance at 

temperature T,and T. can be calculated by 

the equations:' 

X 

k=i 

Eder(35) = the electrical power input of the unit 

at 35 of determined at the intermediate 

compressor speed (k=i) in the frost 

accumulation lest ME=s\ope of the 

electrical power input curve for the 

intermediate compressor speed (k=i) 

(1 - Nl::,) 

where: 
CAS-RM-79-102 COMMENT 12

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='(Tj) 

(at Tj 40'F) equal to the building load 

equation BL(T,) as identified in section 

5.2.2 of this 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(Tj) eaual to the equation 

for building load BL(Tj) from the twospeed procedure in section 5.2.2 and 

solving for temperature 

COPk~1(T3)=the coefficient of performance at 

the minimum compressor speed al 

temperature T3 

T2 2 

D 3 - T4 = 

T 2 2 

vh T4 

B 

COp k=2(T4 ) 

= 

T4 

COPk~2(T4)=the coefficient of performance 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(Tj) 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) of the two-speed 

procedure 

Ek -l(T3 )=the electrical power 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 of this 

Appendix 

The coefficient of performance. 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) - COP k = 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 or equal to the 

heating capacity, Qs."=2(Tj). 

4 

Calculations shall be performed as 

prescribed for two-speed systems in Case IV 

of 5.2.2 

- c)(. T~ 

5.2.5. Heating seasonal performance facto]' used shall be the same as those used for unit 

fo]' split-type ductless systems. For split-type with the same type of compressor. 

ductless systems, HSPF shall be defined as * 

specified in section 5.2.1 of this Appendix. Separate values of HSPF 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 of SEER 

as specified in section 5.1.7. The calculations