CAS-RM-79-102 COMMENT 06

35410 Federal Register I Vol. 51, No. 192 I Friday. October 3, 1986 I Notices 

r,-' 

t Energy Conservation Program For 

) Consumer Products; Petition for 

Waiver of Central Air Conditioner Test 

Procedures From The Trane Co. (CAC-

.002) 

AGENCY: Conservation and Renewable 

Energy Office. Department of Energy. 

SUMMARY: Today's notice publishes a 

"Petition for Waiver" from The Trane 

Company (Trane) of Tyler. Texas. 

requesting a waiver from the existing 

Department of Energy (DOE) test 

procedures for central air conditioners. 

Trane manufactures residential and 

commercial air conditioning appliances. 

The petition requests DOE to grant relief 

from the test procedure relating to the 

compressor speed specification for 

Trane's TTS/TWS model series central 

air conditioners (heat pumps). Trane 

seeks to test using intermediate 

compressor speeds instead of the single 

speed specified. Trane requests the test 

and calculation methods of Appendix B 

to the Air Conditioning and 

Refrigeration Institute Standard 210/ 

240-84. with modifications. be 

substituted for the DOE test procedures 

for central air conditioners. DOE is 

soliciting comments. data. and 

information respecting the petition. 

DATE: DOE will accept comments. data 

and information not later than 

November 3.1986. 

ADDRESS: Written comments and 

statements shall be sent to: Department 

of Energy. Office of Conservation and 

Renewable Energy. Case No. CAC-002. 

Mail Stop CE-132. Forrestal Building. 

1000 Independence Avenue. SW .. 

Washington. DC 20585. 

FOR FURTHER INFORMATION CONTACT: 

Michael J. McCabe, U.S. Department of 

Energy. Office of Conservation and 

Renewable Energy, Mail Station, CE132, Forrestal Building. 1000 

Independence A venue, Washington. 

DC 20585, (202) 252-9127 

Eugene Margolis. Esq" U.S. Department 

of Energy, Office of General Counsel, 

Mail Station GC-12. Forrestal 

Building, 1000 Independence Avenue. 

SW, Washington. DC 20585. (202) 252-

9513 

Background 

The Energy Conservation Program for 

Consumer Products (other than 

automobiles) was established pursuant 

toJhe Energy Policy and Conservation 

Ad (EPAC), Pub. L. 94-163. 89 Stat. 917, as amended by the National Energy 

Conservation Policy Act (NECPA). Pub. 

L. 95-619. 92 Stat. 3266. which requires 

DOE to prescribe standardized test 

procedures to measure the energy 

consumption of certain consumer 

products. including central air 

conditioners. The intent of the test 

procedures is to provide a comparable 

measure of energy consumption that will 

assist consumers in making purchasing 

decisions. These test procedures appear 

at 10 CFR Part 430. Subpart B. 

DOE has amended the prescribed test 

procedures by adding 10 CFR 430.27. 

Petitions of Waiver, to allow the 

Assistant Secretary for Conservation 

and Renewable Energy temporarily to 

waive test procedures for a particular 

basic model. 45 FR 64109 (September 26. 

1980). Waivers may be granted when 

one or more design characteristics of a 

basic model either prevent testing of the 

basic model according to the prescribed 

test procedures, or lead to results so 

unrepresentative of the model's true 

energy consumption as to provide 

materially inaccurate comparative data. 

Waivers generally remain in effect until 

final test procedure amendment become 

effective, resolving the problem that is 

the subject of a waiver. 

Trane's petition seeks a waiver from 

the DOE test provisions that require 

testing at a single compressor speed. 

Trane requests allowance to use Appendix B of the Air Conditioning and 

Refrigeration Institute (ARI) Standard 

210/240-84 with amendments. The 

amendments to ARI Standard 210/240-

84 requested by Trane include revisions 

to cycling period and intermediate 

steady state test point. The intermediate 

speed proposed by Trane matches 

system capacity to building load at 87 

OF. Also, Trane requests the allowance 

of test and calculation procedures which 

incorporate test data for system 

operation at minimum and maximum 

speeds. 

Pursuant to paragraph (b) of 10 CFR 

430.27. DOE is hereby publishing the 

"Petition for Waiver" in its entirely. The 

petition contains no confidential 

information DOE solicits comments. 

uata. and information respecting the 

petition. 

Issued in Washington. DC September 11. 

1986. 

John R. Berg. 

Principal Deputy Assistant Secretary. 

Cotfservation and Renewable Energy. 

July 9, 1986. 

Assistant Secretary. Conservation and 

Renewable Energy. 

United States Department af Energy. 1000 

Independence Avenue, SW .. Washington. 

DC 20585. 

Gentlemen: This petition for waiver is 

being submitted pursuant to 10 CFR. Part 430. 
CAS-RM-79-102 COMMENT 06

Federal Register I Vol. 51. No. 192 I Friday. October 3, 1986 I Notices 35411 

Appendix M to Subpart B, Test Procedures 

for Central Air Conditioners. Including Heat 

Pumps. Waiver is requested for Trane's ITS/ 

TWS model variable speed cooling-only 

products and heat pumps in the cooling 

mode. 

Models in the ITS/TWS product lines use variable speed motors to drive the 

compressor, indoor blower, and outdoor fan. 

The compressor is controlled over a wide 

range of speeds: the indoor blower and 

outdoor fan motors operate over a smaller 

range. Modulation of all three motors allows 

the system to better meet specific load 

requirements, thereby minimizing energy use. 

The system requires use of our microprocessor design in conjunction with a 

special thermostat. offering a wide range of 

additional energy conserving options. 

York demonstrated (Case BEE-1338. 

January 13. 1981) that the current two-speed 

rating procedure did not adequately represent 

true seasonal performance and efficiency of a 

variable speed system, and was granted 

permission to use a modified test and rating 

calculation procedure for their ENMOD heat 

pump products. ARI has since published a 

revised standard (ARI 210/240-84) that 

incorporates variable speed test and 

calculation procedures, almost identical to 

the York method. and plans to further edit 

and revise this procedure. Carrier requested 

that they be allowed to use a modified 

version of the ARI/York procedures in their 

petition of December 4. 1985, which was 

published in the February, 1986 Federal 

Register. 

We believe the York! ARI procedures to be 

the fairest method of estimating variable 

speed system cooling performance. However. 

the York/ ARI procedures require further 

clarification for laboratory repeatability and 

verification purposes. Carrier attempted to 

address this issue in their petition. but some 

of their proposed procedures, such as the 

"floating intermediate point" testing. were 

not specific enough to ensure a consistent 

interpretation of test data for rating of 

variable speed products. Furthermore, the 

Carrier petition appears to be predicated on the specific design details of their intended 

product offering. 

This petition is a request for authorization 

to substitute the test and calculation 

methods, with some minor modifications. of 

Appendix B of ARI 210/240-84 for Appendix 

M. Subpart B of Part 230 as applied to the 

cooling mode of variable speed products. The 

modifications proposed herein are 

independent of design details of any specific 

system. and are offered as a universal rating 

procedure for variable speed air conditioners 

(and heat pumps in the cooling mode.) A 

subsequent petition will be submitted. as 

appropriate. for rating of heat pumps in the 

heating mode. 

The proposed rating method and 

modifications. to ARI 210/240-84 are 

described below and further detailed in an 

attachment. Graphical representations of the 

requested procedure can also be found in the 

attachment. 

1. Two steady state test points at both 

minimum and maximum speed are used to 

establish a pair of lines that describe the 

extremes of the operating range as a function 

of outdoor temperature for both capacity and 

energy usage. The specific points and 

equations for the lines are defined in ARI 

210/240-84. Appendix B and in the 

attachment. Proposed procedural 

clarifications are as follows: 

A. Rated capacity for the system will be 

based on the tested capacity at an indoor 

condition of 80 OF dry bulb and 67 OF wet bulb 

and an outdoor condition of 95 OF dry bulb. 

maximum speed. with minimum indoor static 

pressure requirements as defined in ARI 210/ 

240-84. Section 5.1.3.6. 

B. We propose that indoor airflow at 

speeds lower than maximum be determined 

by using the fan laws for fixed resistence 

systems. The ratio of measured fan speed to 

maximum fan speed is multiplied by the 

volumetric airflow rate at maximum speed. 

Minimum static requirements only apply at 

the capacity rating point (Test A. Table 1 in 

the Appendix). This modification was also 

requested in Carrier's petition. 

C. Outdoor airflow is as determined by the 

unit controls. Neither Carrier nor York 

addressed variable outdoor airflow. 

2. A building cooling load line. described 

by Equation 1 in ARI 210/240-84. Appendix 

B. and the attachment. is applied to the 

minimum/maximum operating lines so that 

the distinct operating modes (Le .• max. speed 

operation vs. load matching vs. cycling) can 

be established. No modifications in the 

building cooling load line are requested. 

The temperature intersections of the 

bUilding cooling load line and the maximum 

speed and minimum speed lines define the 

modulating speed range of the system. At 

temperatures above the intersection of the 

load line and the maximum speed line. the 

system will operate continuously at 

maximum speed. At temperatures below the 

intersection of the load line am! the minimum 

speed line. the system will cycle on and off. 

3. Additional intermediate points in the 

load matching area could be tested to more 

accurately describe the system's energy 

reduction at lower speeds. Our testing 

confirms the work done by York. which 

indicated that a linear relationship for an 

energy approximation in the load matching 

area does not adequately reflect the 

reduction in energy usage at the lower speed 

range. This deficiency can be substantially 

eliminated by measuring the energy 

consumption at a test condition which 

matches system capacity to bUilding load at 

87 OF. This approach is consistent with both 

the York petition and ARI 210/240-84. 

However. neither of these references 

stipulated a tolerance for acceptability of the 

match between the load line and the system 

capacity. Our proposal is that this match be 

defined by: 

A.1f the measured capacity is within 1% of 

the calculated building load at 87 'F. then the 

tested power is used as described in ARI 210/ 

240-84. Case II Calculations. 

B. If the measured capacity is within 3% but 

not withn 1% of the calculated building load 

at 87 OF. then another test point is run per the 

procedure below. and the power at the 87 OF 

bin is interpolated based on the two points 

and the calculated cQoling building load at 

87 'F (details in attachment). 

1. If the first tested capacity falls above the 

building load line. then the speed is lowered 

so that the second test capacity is below the 

building load line and within 3% oi the line. 

Z.If the first tested capacity falls below the 

building load line. then the speed is raised so 

that the second test capacity is above the 

buiding load line and within 3% of the line. 

C. A measured capacity that is not within 

3% of the calculated building load at 87 OF is 

unacceptable. and the point must be rerun. 

In contrast to this proposal. Carrier's test/ 

interpolation procedure appears to have bet!n 

written for their specific system. It is unfair to 

assume that all variable speed systems will 

have similar speed range and other operating 

characteristics. There may be significant 

differences in operating characteristics which 

make it difficult to specify an intennediate 

test by .peed. Testing based OD building load. 

a. in the York/ARI procedures. will be more 

applicable to a broader range of variable 

speed products. 

4. Using the system power at each extreme 

of the load matching region and the measured 

power at the intermediate point(sJ. the power 

at the bin temperatures in the load matching 

region can be approximated using a series of 

straight line relationships. This procedure is 

described in ARI 210/240-84. Appendix B. 

Case II Calculations and in the attachment. 

No modifications to it are requested. 

5. For the portion of the load line where the 

unit is cycling. ARI 210/240-84. Appendix B 

allows the option of using a degradation 

coefficient value (Cd) of 0.25 or performing 

cycling tests at the 67 OF bin temperature. 

which we agree is representative of the 

temperature range in which cycling actually 

occurs for variable speed products. However. 

variable speed products will cycle less than 

single speed products. 

A. We propose that the "on" time for cyclic 

testing be determined by the minimum "on" 

time allowed by the controls or multiplying 

six (6) minutes by the maximum to minimum 

speed capacity ratio at 00/67~7. whichever 

is longer. For example. a product having a 2:1 

maximum to minimum capacity ratio at 00/ 

67~7 would be tested with the longer of 12 

minutes or the minimum "on" time allowed 

by its controls. This is consistent with the 

stated intent of carrier's proposal. but sets a 

specific procedure that can be applied to a 

broader range of variable speed products. 

B. We propose that the "ofr' time for cyclic 

testing be determined by either the minimum 

"off" time allowed by the controls or thirty 

(30) minutes less the "on" time, whichever is 

longer. This procedure. unlike Carrier's 

proposal. maintains a comparable 30 minute 

cycle for all systems when practical. and 

credits those systems whose controls allow 

less cycling. 

6. For the portion of the load line where the 

unit is operating at maximum speed. both the 

capacity and power of the system at 

maximum speed. as determined by the 

el!tablished maximum operating line. are 

used as described in ARJ 210/240-84. 

Appendix B and the attachment. No 

modifications are requested. 

Test data could be supplied to further 

demonstrste that the proposed method of 

rating variable speed products in the cooling 

mode is more representative of the efficiency 
CAS-RM-79-102 COMMENT 06

35412 Federal Register I Vol. 51. No. 192 I Friday. October 3. 1986 I Notices 

of a variable spl:led system than the current 

two-speed rating method. 

. We understand that York's ENMOD model 

variable speed system is no longer being 

offered. No other manufacturer to our 

knowledge is domestically marketing a 

product that incorporates variable speed 

compressors. blowers. and fans in their 

design. 

Sincerely. 

L.E. Chaump. 

Vice-President Engineering. 

Attachment I: Details of Rating Method for 

Variable Speed Products in the Cooling Mode 

This attachment is a revised version of ARl 

210/240-84. Appendix B. The changes 

reflected herein are to adapt the appendix to 

the proposed rating method and to clarify 

notation and terminology. 

BILLING CODE &450 .. el1 .... 

f 
CAS-RM-79-102 COMMENT 06

Federal Register / Vol. 51. No. 192 I Friday. October 3. 1986 / Notices 

ATTACHMENT I: DETAILS OF RATING METHOD FOR 

VARIABLE SPEED PRODUCTS IN THE COOLING MODE 

Test conditions and methodology for rating unitary air conditionin9 with 

variable speed compressors as diagrammed in Figure 1. 

I. Test Conditions 

35413 

1.1 The tests and test conditions which are required to determine values of 

capacity ratings and values of measure of energy efficiency appear in 

Tabl e 1. 

1.2 The "on" time for cycl ic testing is determined by the minimtrn "on" time 

" allowed by the controls or multiplying the maximum to minimtrn speed 

capacity ratio at 80/67-67 by six minutes; whichever is longer. 

qk-Z (67F) "on" time :II: 55 (6) 

It.:./ (67F) qss 

where q;s"z (67F) is determined us ing eq. (4) 

q*-I (67F) is from Low Ambient Cooling Steady State Test, u Table 1. 

1.3 The "off" time for cyclic testing is determined by the minimum "off" 

time allowed by the controls or thirty minutes less the determined "on" 

time from 1.2 above, whichever is longer. 

1.4 In lieu of conducting the Cyclic Cooling and Low Ambient Dry Coil 

tests, an assigned value of .25 may be used for the cooling degradation 

coefficient, CO, 

1.5 Minimum indoor static pressure requirements as defined in ARI 

210/240-84, Section 5.1.3.6, apply to Test A in Table 1. 

1.6 At speeds less than maximum, the indoor airflow is determined by the 

following equation: 

CFMk=v = RPMk=v CFMk=2 

RPMk=z 

where 

CFMk=V = Airflow rate at lower speed 

CFMk=2 :II: Airflow rate from Test A in Table 1 

RPMk=z :II: Fan RPM from Test A in Table 1 i 

RPMk=v = Fan RPM at lower speed 
CAS-RM-79-102 COMMENT 06

35414 Federal Register I V.oL 51. No. 192 I Friday. October 3, 1986 I Notices 

2. Calculations (NOTE; Refer to 81ft Analysis Method in ASHRAE 116) 

2.1 Cooling Seasonal Performance Factor. For variable speed compressor units the seasonal energy efficiency ratio (SEER) is found from the 

following equation: 

II 

~ q(~J SEER = 1..: 1;"..;1_-

~ E(t,) 

i-I 

The terms q(tj) and E(tj) as defined in ASHRAE 116, summed over 

temperature b1ns, are evaluated at each temperature bin according to 

the three possible casees 1isted below. 

The buUding coo11ng load BL(tj) for the three cases is obtained from 

the following equation: 

eq.(1) 

. BL(t) = tj - 65 {q!;2 (9SF)] 

195 - 65 Size Factor 

where q!s·2 (95) - steady state capacity measured from Test "A" in Table 1. 

Size Factor • 1.1 for lOS Dversizing. 

CASE I 

Units operating at minimum compressor speed (k-1) for which the steady state 

cooling capacity~f(tj)is greater than or equal to the building cooling load 

BL(tj), evaluate the tollowing. 

eq. (2) 

qle.1 (82F) - Ie-I (67F) 

Ie - I (t)= Ie - I (67F) + ss qss (t - 67) qss I C};s 82 - 67 I 

where q!-l (67F) - steady state capacity measured from the Low Ambient Cooling Steady State Test, Table 1. 

q!-] (82F) - steady state capacity measured from Test -8-1", Table 2. 

- steady state capacity at the rnin'rnllll compressor speed intended for normal operation in the cooling mode at 

temperature tj. 
CAS-RM-79-102 COMMENT 06

Federal Register I Vol. 51. No. 192 I Friday. October 3. 1986 I Notices 35415 

eq. (3) 

E:S-I (t:) = E:S-l (67F) + E~.f·1 (82~~ = ~~;l (67F) (tj - 67) 

where E~-I .(67F)- the electr1·cal power input for the Low Pmbient Cool 1n9 

Steady State Test. 

E~.J-I (82F) - the electrlcal power input fr9lft Test -B-l-

- the electrical power input at the minimum compressor speed in the- cooling mode at temperature tje 

Cooling Building Load Factor 

Cooling Part Load Factor 

where C() is as defined in Chapter 9 of ASHRAE 116 with the Dry Coil Cool ;n9 

Steady State test construed as -Test C and the Cyclic Cooling Dry Coil test 

construed as Test D •. both run at minimlJll compressor speed. (See Table 1) 

q (t) = X* -I q* -I (t) n I . .f.J I I 

where nj • is the number of cooling hours in the jth temperature bin 

given in AR I Standard 210/240.. Append 1 x A. 

( 
CAS-RM-79-102 COMMENT 06

35416 Federal Register / Vol. 51. No. 192 I Friday. October 3.1986 / Notices 

CASE II 

When the compressor speed varies between the maximum (k=2) and minimum (k=l) 

compressor speeds (such that k-v, to satisfy the building cooling load a 

temperature tj' (NOTE: unit does not cYcle on and off), evaluate the following eQuations. 

q~s-" (t,) = BL(t,) 

where qk." (t) • steady state capacity del ivered by the unit at any speed between 

U minimum and maximum compressor speeds at temperature tj' 

when tj ~ 87-F 

where tz - temperature tj at which q~-1 (tj) • SL (tj) found by equating 

eq.(l) and eq.(4) and s01y1n9 for tj' 

E!.-2 (t2). the electrical power input at max'il1lUll COII'Ipressor speed at 

temperature t2 calcul ated from ceq. (S) • 

E~-" (t,). the electrica' power input required by the unit at 

temperature tj and some variable compressor speed between the 

minimum and maximum compressor speeds. . 

E!.-" (87F)· the electrical power input at 87f, from either equation (6) or 

equations (7) and (8). 

When the measured capacity at the intermediate test point (Table 1), 

q~;~'(87F)' is within lS of BL(87F), then 

eq. (6) 

f 
CAS-RM-79-102 COMMENT 06

Federal Register / VoL 51, No. 192 I Friday, October 3.1966 I Notices 

When two intermediate points are measured, where one measured capacity, kaWI • • ",aVZ 

QUI (87F), is wlthln +3% of BL(87F) and the other, q"z (87F), is within 

-3% of BL(87F). then· E~$-'" {87f) is evaluat~d \Ising i!q.(7) and {B)~ . 

eq. (7) 

WEIGHT • 

eq. (8) 

When tj<a7 af 

k-vl qS;1 (87F)- BL{87F) 

q~:~{87F)- q~;2{87F) 

E" -] (t ) - E"·" (87F) E*-" (t) = E*-" (87F) + ,u ! Q (t - 87) IS I IS • t;! - 87F ' 

where tl • tenperature tj at ~1i:h ~.I (t,) • BL(tj} found by equating 

eq.{l) and eq.(2) and so1v1ng for tj. 

35417 

Ek - I (t 1

) • the electrical power input at min1m\Jn compressor speed at 

t~perature tl calculated from eq.(3). 

q (t,) = q:.,-" (t,)o, 

E (tt) = E~s-" (tJ Of 

f 
CAS-RM-79-102 COMMENT 06

35418 Federal Register / Vol. 51, No. 192 / Friday, October 3, 1986 /Notices 

CASE III 

~When I unit operates continuously at maximum compressor speed (k-2) at an 

ou'tdoor temperature tj. evaluate the following equations: 

+ q!-2(95F) - qsks·2(82F) ok - 2 (82F) (t 82) - "'ISS '95 - 82 " I -

where q~;2 (t/

) • steady state capacity at the maximum compressor speed at 

temperature tj. 

q!-2 (82F) • steady state capacity from Test "B-2", Table 1 

eq. (5) 

Ek -2 (t) = Ek -,1 (8'F) +E~-2 (95F) - E~s·l (82F) (t - 82) ss I JS - 95 - 82 " 

where Ek-:Z (t) • the electrical power input at the maxim"" compressor speed at SJ J temperature tj. ' 

E~·2(82F) • the electrical power input from Test "B-2", Table 1 

E~·:Z(95F). the-electrical power input from Test "A", Table 1 

- q (t,) = q:s·2 (t,) n, 

E (t) = E~s-2 (t/) n, 

, 

( 
CAS-RM-79-102 COMMENT 06 

Federal Register I Vol. 51. No. 192 I Friday, rk\ober 3, 1986 I Notices 35419 

lAlil( t.; Test Conditions 

. INDOQRCOll OUrDooR COIL 

lest 

AIR EHtERIHG AIR ENTERING 

r ~ ~8 

-A- Cooling Steady Stat. 

At M41imum (k-Z) COIIIpfeSSor SDHd 

90 61 9S 

-8-2- Cooling Steady St.tt 

At Maximum'(k.Z) Compressor $pt.d 

ao 61 82 

-8-1- Cooling Steady State 80 61 82 

At Min1mum'{k-U Compressor SDeed 

Low Ambient Cooling Stead~ Stat. ~ 6' 67 . 

At Minim'.II,dk-l) Compressor SDetd 

Ofy Coil cooling Steady Stitt 80 57 4 11 

At "in1mum (k-l) ComprfSSor Speed 

3 80 57 4 

Cyclic Cooling O"y Coil 6' 

At M'nim~ (k-l) Compressor SCetd 

Intermediate Cooling Steady State2 

At Variable (kay) CompreSs(lf Spttd 

80 67 81 

All TISts Irt perfOnlled It th. condense,. spted and indoor blower 'J)Hd intended tot nortIIa1 cp ... ,t1on. 

NOTES: 

1. Hot maintained if no condensate rejected to outdoor coil. 

Z. Compre'S\or speed 1s selecttd to provide capacity as described 1n Case II calculations; Attachment 

test conducted by cycl1ng compressor .S descr'btd 1n Attachment I. Sect10nS 1.l and 1.3. 1. 

4. Wet bulb sufficiently low that no condensate forms on evaporatOr. 

IF'R 000. 86-2a418 Filed 10-.2-116: 8:45 IIml 

"WHO COOl '.!IOoO'-C 

.. . 

r. 

~8 

1s1 

651 

651 

53.5 1 

53.5 1 

53.5 1 

191