## Federal Register / Vol. 48, No. 94 / Friday, May 13, 1983 / Notices

I* 21629

Office of Conservation and Renewable Energy
[Case No

. F-0071 

## Energy Conservation Program for Consumer Products ; Petition for Waiver of Furnace Test Procedures' from Honeywell, Inc.
AGENCY : Department of Energy. SUMMARY: Today's notice publishes a Petition for Waiver" from Honeywell, Inc. (Honeywell), requesting a waiver from the existing Department of Energy (DOE) test procedures for furnaces. Honeywell is requesting the allowance to use an alternate test procedure in its testing of furnaces and boilers equipped with a Honeywell "Integrated Control System" (ICS). DOE is soliciting comments, data, and information respecting the petition. DATE : DOE will accept comments, data, and information not later than June 13, 1983. ADDRESS : Written comments and statements shall be sent to: Department of Energy, Office of Conservation and Renewable Energy, Case No. F-007, Mail Station CE-113.1, Forrestal Building, 1000 Independence Avenue, SW., Washington, D.C. 20585. FOR FURTHER INFORMATION CONTACT: Michael J. McCabe, U.S. Department of Energy Office of. Conservation andRenewable Energy, Mail Station CE113.1, Forrestal Building, 1000 Independence Avenue SW., Washington, D.C. 20585 (202) 252-9127 Eugene Margolis, U.S. Department of Energy, Office of General Counsel. Mail Station GC-33, Forrestal Building, 1000 Independence Avenue SW., Washington, DC 20585 (202) 252- 9513.

## 21630 Federal Register / Vol. 48, No. 94 / Friday, May 13, 1983 / Notices

SUPPLEMENTARY INFORMATION: Background 

### The Energy Conservation Program for Consumer Products (other than automobiles) was established pursuant to the Energy Policy and Conservation Act (EPCA), Pub. L. 94-163, 89 Stat. 917, as amended by the National Energy Conservation Policy Act (NECPA), Pub. L. 95-619, 93 Stat. 3266, which requires DOE to prescribe standardized test procedures to measure the eneigy consumption of certain consumer products, including furnaces. 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 for Waiver, to allow the , Assistant Secretary for Conservation and Renewable Energy temporarily to. waive test procedures for a particular basic model. 45 FR 64108 (September 26, 1980). Waivers may be granted when one or more design characteristics of. 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. 

## On January 7,1983, Honeywell filed a Petition for Waiver from DOE test procedures for furnaces. Specifically, the petitioner believes that the use of the existing furnace test procedure will not accurately evaluate a furnace or boiler equipped with Honeywell's Integrated Control System (ICS). Honeywell claims that its ICS is a control system that will provide efficiency enhancement through control of multiple burner firing rates and circulator run time. The multiple burner firing rate is the aspect of the system that constitutes the substance of the request. Honeywell's petition includes a suggested method of weighing the Annual Fuel Utilization Efficiency (AFUE) values at two firing rates in lieu of the currently prescribed provisions which only allow evaluation at the highest firing rate. Honeywell believes this weighted average method will accurately evaluate the performance of any furnace or boiler equipped with the ICS. Honeywell requests the allowance to use the weighted average method, including the use of the specific weighting factor of 16 percent fuel consumption at high fire. Pursuant to paragraph (b) of 10 CFR § 430.27, DOE is hereby publishing the "Petition for Waiver" in its entirety. The petition contains no confidential information. DOE solicits comments, data and information respecting the petition, particularly with regard to thQ appropriateness of the weighted AFUE. method and the weighting factors ' suggested by Honeywell (i.e. 16% high fire, 84% lowfire). Issued in Washington, D.C. April 18, 1983. Howard S. Coleman, Principal Deputy Assistant Secretary Conservation and Renewable Energy. January 7, 1983. 

### Mr. Joseph Trible, Assistant Secretary for Conservation, and Renewable Energy, U.S. Department of Energy, ioo0 independence Avenue SW., Washington, D.C. 20585 Dear Mr. Trible: This is a request for waiver, for Honeywell only, from the Consumer Product Test Procedure as specified in 10 CFR Part 430, amended on September 26, 1980, for application to furnaces and boilers using a Honeywell Integrated Control System (ICS). Appendix N to Subpart B of 10 CFR Part 430 specifies the test procedure to determine the relative efficiency of manufacturers' appliances. Section 430.24 of Subpart B prohibits a manufacturer from representing energy efficiency of products unless based on results obtained as specified in Appendix N to Subpart B. We believe this test procedure will not accurately -evaluate a furnace or boiler equipped with an ICS. 

### In addition to many-control and diagnostic functions, the Honeywell ICS provides multiple burner firing rates with fuel/air ratio control, as well as circulator overrun on warm-air furnaces. Our testing on over 20 appliances shows the strategy will increase AFUE by up to four percentage points with the rationale that the appliance is 70% oversize for the structural (Ref.: 10 CFR Part 430, Appendix N to Subpart B). Appendix A gives a system overview of the multiple firing rate circulator overrun control methods. Appendix B suggests an alternate test procedure to accommodate these efficiency enhancement features. Appendix C describes a computation procedure for determining the fraction of time the burner operates at high fire, assuming 60 seconds of high fire operation at the start of each thermostat cycle. 

### Honeywell is requesting the allowance to use the weighted average method specified in Appendix B. including the use of the weighing factor of 16% fuel use at high fire. Your consideration of this request for waiver from the Consumer Product Test Procedure will be very much appreciated. Best regards, Ralph Torborg cc: Mr. John Talbot, Consumer Product Efficiency Branch, Conservation and Solar Energy, U.S. Department of Energy, Washington, D.C. 20585 Mr. Esher l weller, National Bureau of Standards, Building 202, Room 204, Washington, D.C. 20234 Mr. Jack Langmead, GAMA,1901 North Fort Meyer Drive, P.O. Box 9245, Arlington, VA 22209 Mr. John Woodworth, Hydronics Institute, 35 Russo Place, Berkely Heights, NJ 07922 

### Mr. Jack H. Hollingsworth, ASI-IRAE, 31081 Aliso Circle, South Laguna, CA 92677 Appendix A-System Overview Integrated Control System (ICS) The Honeywell Integrated Control System is an advanced technology system that provides overall control of a gas-fired furnace or boiler by incorporating all necessary control functions. The logic functions are performed by a microprocessor located within the System Control Module. This module contains the electronics required to interface the axstem components with the microprocessor. The system uses a two-stage gas valve with a redundant actuator. Proof of flame is provided by a conventional flame rod. The system utilizes a solid state temperature

sensor which indirectly controls the circulator during normal operation, or shuts off the gas valve if an over-temperature condition exists. 

### Combustion air is controlled by a power combustion blower (PCB) assembly with an electronic speed control module to provide high or low combustion air. By controlling the speed of the PCB and the gas valve, the System Control Module can control combustion air and fuel for two -stage firing. With this system, the capability to control the quantity of combustion air and gas independent of each other has significant safety, reliability and efficiency results. By executing ignition with high air and low gas (low F/A ratio) the possibility of flame-roll out from the vestibule is eliminated. Tests show that with a low F/A ratio, a smooth, quiet ignition is assured even after a 15 minute delay. This is because the F/A ratio goes below the ignition point rapidly as the distance off the burner surface increases. Once ignition is established, the system goes to high-fire to reduce the time the heat exchanger is exposed to corroding condensation with obvious reliability advantages. • On forced warm air systems, it stays in high-fire for 80 seconds maximum or until the plenum temperature sensor reaches 140°F (but30 second minimum). Normally, this will result in a 60 second high-fire start. • For hydronic systems , the boiler goes to high-fire on a call for heat and remains in high-fire until the H:O temperature reaches 105'F (but 30 second minimum). Thus, the system may remain in high-fire each cycle for as little as 30 seconds or for several minutes depending on the mass of the boiler and return water temperature. For our calculations of high-fire fuel use , we assumed 60 seconds of high-fire operation at the start of each thermostat cycle. At all but very light loads, the return water would still be warm at the start of a heating cycle and would quickly be above 105°F even for relatively massive boilers. One minute of high-fire start, therefore, seems reasonable. 

### After the high-fire start the system goes to low-fire. If low-fire is inadequate to handle the load. the system automatically returns to. high-fire.

### Federal Register / Vol. 48, No. 94 / Friday, May 13, 1983 / Notices

The system utilizes a conventional single stage thermostat; but contains a special thermostat algorithm that operates the gas valve and the induced draft blower so as to efficiently match the heating load while maintaining a constant F/A ratio. The system will operate at a low firing rate, except after ignition as stated above and during conditions of morning setup or during exceptionally cold weather. Two stage operation is controlled by a counter. If the call for heat remains on, in 10 minutes the counter will reach its maximum count and call for high-fire and high air. When the call for heat goes away,- the burner shuts down and the counter resets to zero. Circulator overrun operates as follows: • On forced warm air systems, the circulator turns on 60 seconds after start-up or when the plenum temperature reaches 140° F, whichever occurs first. After the heat request is satisfied , the circulator continues to run until the warm air plenum temperature sensor drops to 95° F. • After a call for heat on hydronic systems, the circulator comes on when the boiler H2O temperature rises above 105° F. The circulator shuts down when the thermostat is satisfied. Appendix B-Proposed Alternate Test Procedures 1. Perform entire test as specified in Appendix N to Subpart B contained in 10CFR. Part 430, with burner sel at rated high-fire input. Circulator should be controlled by the ICS. 2. Repeat above test with appliance operating at its low-fire input. 3. Determine fraction of heating season fuel consumed at high-fire input (see Appendix C). 4. Determine the effective AFUE as follows: AFUE (effective)=X (AFUE High) + (1-X) (AFUE Low) Where X=% fuel used during high-fire operation=16% Example: AFUE @ High-Fire-80% AFUE @ Low-Fire-82% % Time @ High-Fire-16% AFUE (effective) = (.16x80) + (.84 X 82) _ 81.7% Appendix C The fraction of heating season fuel consumed by the appliance at high-fire can be determined for various low-fire (derate) conditions. Low-fire derate is defined as the percent reduction form high-fire. In the ICS, low-fire output is about 60% of high-fire output (40% Berate). The calculation procedure in Table 1 was used to determine the fraction of fuel consumed at high-fire for the ICS. 

### In the calculation procedure, the following assumptions were made: (a) Burner starts each thermostat cycle at high-fire for 60 seconds. (b) Thermostat cycling rate for the ICS with two stage firing is three cycles per hour @ 50% load. (c) National average weather (Pittsburgh). 

## 21631

(d) Appliance is 70% oversize. 

### (e) Both steady state and cycling efficiency follow the trend shown in Figue 1. (f) Cycling efficiency is Independent of cycling rate and/or thermostat load (Figure 2). The heating season was divided into outdoor temperature "bins" (see Table 1). AT is the indoor/outdoor temperature difference, i.e., the difference between 65°F and the average of the "bin". Thus, AT represents the heating load in degrees. The heating season hours in each "bin" were determined from Pittsburgh ( national average ) weather data. The percentage load at high fire (H) is the ratio of the heating load, AT, to the temperature rise achievable by the appliance if it is on continously . The outdoor design temperature for Pittsburgh is 1°F (based on ASHR_'tE data. Pittsburgh airport temperature. exceeds 1`F, 99% of the time during December, January, and February). The design load is thus 64 °F (65'F-1°F). The temperature rise achievable by the appliance, assuming 70 % over- size
, is then 109°F (64°F X 1.7). Thus, to calculate Col. 4, Table 1: H = AT/109'F The next column "Total Hours Required (high-fire only)" shows the hours in each "bin" that the appliance must operate in highfire to satisfy the load (Col. 3 X Col. 4). 

### The load at combined high-low fire (F,) is defined in terms of the load at high fire (H) by the following expression:

F. = 0.68 0 .46

V 2-0.32H (1) 0.016
The derivation of Equation 1 proceeds as follows: The average energy output of a heating appliance a combined high-low fire for each temperature "bin" (Table 1) must be equal to the average output at high fire only (to satisfy the space heating demand). OUTPUTHI=OUTPUTHr1,, (la) The average energy output is also equal to the instantaneous output at high fire (QHI) times the load at high fire (H) OUTPUTHI=QHIH (1b) At combined high-low fire, the energy output for one thermostat cycle is as follows: OUTPUTHrt. /C=QH1T,+Q,.,(Ten-TI) where: C=thermostat cycling rate T,= on time/cycle at Hi Fire 

### T,n=on time /cycle for combined Hi-Lo Fire Defining: R=Q,.,/QH1 OUTPUTH,,.o=C (QH1T1+RQH,(T,n-T,)l From equations la and 1b:

Q141H 

### =C (QHIT,+ R QHI(Tun -T,)l Then: H=C (T,+R(Ton 

## -T,)l (2) Now, to find an expression for thethermostat cycle-rate, C, In terms of the twostage firing load, F„ we must consider the operation of a typical thermostat with thermal or electronic anticipation. As discussed in "Guide to Room Thermostats," Appliance Manufacturer, Sept. 1971, p. 89. a thermostat consists of a temperature sensitive differential switch (e.g., mercury bulb with bi-metal) that receives some form of feedback or "anticipation." The anticipator response may be treated as a first-order lag and the resulting differential equation may be solved at the make and break points of the differential switch to determine T,n and C as a function of percent heating load. F0, as shown in Figure 3. The resulting expressions, however, are transcendental functions of F. which must be solved iteratively. An approximation of this function which allows a closed form solution is given by: C=4C,,F,(1-F,) (3) where Cs,=thermostat cycle rate of half-load; e.g., three cycles per hour. Equation 3 was obtained through a second order curve fit to curve C in Fig. 3. The thermostat on-time is easily found, knowing F. and C by noting:

on

C=

ron=F, ('on +'offl= F, C 'on + 'off

I cycle
'on + 'off

(4)

Solving equations 2, 3, & 4 simultaneously gives equation 5, given the following: Cso=3 cy/hr '1=1/60 hr R=0.6 H=0.68 F,-0.08 F,, (5) Solving equation (5) using the quadratic formula gives equation (1). The negative value of the square root quantity must be used because the positive value results in a load greater than 100%. F. is calculated from Equation 1 and is tabulated for each "bin" in Table 1. The cycling rate (C) is then determined from equation 3 and shown in Table 1. Col. 7. The cycles per year (Col. 8) are equal to the cycles/hr. times the heating season hours in each temperature "bin". The thermostat cycling rate (C) was calculated assuming a cycling rate of three cycles per hour at 50% load. A Honeywell T87 thermostat, with the anticipation set to match the gas valve current at high-fire, would cycle six times per hour at 50% load. However, at low-fire, because of the reduced anticipation current (one less gas valve operator), the thermostat will cycle three times per hour at 50% load. For solid state thermostats (no thermal anticipation) the cycling rate should be set at three cycles per hour (50% load). The use of a two-stage firing control enables the use of a slower cycling thermostat to produce comfort conditions (i.e., room temperature fluctuations) identical

## 21632 Federal Register / Vol. 48, No. 94 / Friday, May 13, 1983 / Notices

to a single stage firing control with a faster cycling thermostat. This is because the two stage control operates at low-fire , and hence at a lower capacity , for most of the heating ,

season . As shown in Figure 4 (this figure is an unpublished extension of a study entitled "Analytical Predictions of Residential Electrical Heating System Performance," by Lorne W

. Nelson and John L

. Magnussen, IEEE Transaction on Industry Applications, Vol. IA-10, No. e, Nov./Dec. 1974), space temperature swings are 1) inversely proportional to the first order time constant which approximates the dynamic response of the appliance's heat output rate from a cold startup and 2) inversely proportional to the on/off cycling rate at half load. Additional unpublished studies have shown that space temperature swings are 1 ) directly proportional to the capacity of the appliance or appliance heating stage being cycled and 2) independent of load between 20%-80%. Thus, a given appliance operated at five cycles per hour at high-fire (Ref. DOE test procedure NBSIR 78-1543, page A-9) could be operated at three cycles per hour at a 40% derate firing rate with negligible difference in space temperature swings (as shown in Figure 4) for a given appliance time constant. Moreover, derating a given appliance increases the appliance time constant (smaller heat input rate for the same thermal

mass ) which reduces space temperature swings even further. Therefore, an appliance normally operated by a 5-6 cycle per hour thermostat could be operated by a three cycle per hour thermostat with two stage control with no noticeable effect on homeowner comfort. The existing DOE test procedure is based on a thermostat cycing rate of five cycles per hour at 50% load. The test procedure also is based on a load of 22.5%. With the ICS, the duty cycle will be considerably higherbecause the appliance will operate at lowfirst most of the heating season. Also, the cycling rate will be lower (as described above). With a power-combustion-blower equipped heating appliance the effect of thermostat cycling rate and % load on the energy performance is very small due to low off-cycle losses (see Figure 2). The DOE test procedure
, then, will give accurate representation of the energy performance of a heating system equipped with an ICS. Referring again to Table 1, the hours accumulated in high-fire start up (60 seconds each thermostat cycle) are calculated for each "bin" based on the number of thermostat cycles per year. This data is shown in Table 1, Col. 9. When low- fire is inadequate to supply the required heat, the control system reverts to high-fire. For the ICS with a 40% derate, low-fire (with a 80 second high-fire start each burner cycle) will satisfy the heating demand for all but the two "coldest" temperature "bins" (The maximum ill satisfied by low fire (60% of high fire output) is 0.6 X 109°F=65°F.) Since these "bins" represent less than 0.5% of the heating season hours, they were ignored. The total hours the appliance operates at high-fire is then simply the hours accumulated during the 60 second high-fire starts. The ratio of the total high-fire start hours (218.2) to the hours required to satisfy the entire heating season load at high-fire (1,372.7) determines the fraction of fuel used at high-fire. For the ICS, this fraction was determined to be 0. 16; i.e ., 16% of the annual fuel consumption is consumed with the heating appliance operating at high-fire. The effective seasonal efficiency (AFUE) can then be determined from the procedure described in Appendix B.

TABLE 1.-PROCEDURE FOR DETERMINING PERCENT HIGH FIRE FUEL USE AT 40 PERCENT LOW-FIRE DERATE Pittsburgh Weather 70 percent Oversize

Therrrwstat
Temperature Bins (F) A T Heating season fours (H) Hi -fire

percent load Total Hr.

reG wired (Hi- (Fo)Hi /LO

combined C 60 Second Hifire start fie only) percent badk (hours) Cycle/Hr. Cycle/Yr.

601o64 ......... ___._-_..... 3 823 2

.8 23.0 4.4 0.5 412 6.9 55 to 59 ._ ........... :.... _....... _.......... _.._..............»........._------ 8 691 7

.3 50.4 10.6 1

. 13 781 13.0 5o to 54 ............ ............................................. ...» 13 - 843 11.9 76.5 18.1 1

.80 1.157 19.3 45 to 49._..»..._...... _........................................ ».._........ 18 583 16

.5 962 25

.0 2.25 1
,312 21.9 40 to 44...... ............... ............._.......................»...._...._...._ 23 624 21.1 131

.7 32.5 2

.63 1,641 27.4 35 to 39 .......... ..._..... _...... .._...._......... .... _.._......._....-.._._. 28 680 25.7 174

.8 40.0 2

.87 1,952 32.5

.................... ............ .».............__._„._.... 30 to 34

............ . 33 784 30

.3 237

.6 47.5 2.98 2.336 38.9

.. 25 to 29.................. ........ _..__--------- _....... __.._._._..._.... 38 541 34.9 188

.8 55.0 2.95 1.596 26.6 201o24 ----------------- -- ..._.._•..-.._.-._._...__.._._.... 43 326 39.4 136

.3 62.5 2

. 50 969 162 15 to 19 ..._..._..........._...w_...._»....._...... _....... ._...._......_. 48 226 44.0 99

.4 70.6 2

.46 560 9.3 10 to 14 ..... _ ........ ............... _..._..........»..._»._........_.__....... 63 163 48.6 792 85.0 1.52 24B 4.1 5 to 58 82 53

.2 43.6 87

.5 1.30 107 1.8 0 to 4 ...__.»»_.._.........._._._._._.»___»..._.__...___._.._.... 63 . 40 57.8 23

. 1 96.3 0

. 45 18 0.3 -5 to (-1)....._.._.»»._ .................^.^_»...._........._._..... as 15 62

.4 9.4 100

.6 0 0

........................... -1010(-G) ....................... ....................... »_._............. 73 4 67. 6 2.7 115

.0 0 0 ............. __........ Total ._.._..___.._..Y.»_._...._._.
._...._........ _ ........ ....... ........... _...... .......__.._...__.._.. 1,372

.7 _r......_.___..._... .._».„.._._........_. ............_.....w_..... 2182



### High

-Fire Fuel Use:

218.2

BILLING CODE 8450-01-4 = .16

1371.784

83

82

81

80 CIG 1. TYPICAL EFFICIENCY VS. DERATE

(ASSUMED VALUES)

0 10 20 30 PITTSBURGH WEATHER 70, OVERSIZE TOO ON HEATING SYSTEM EFF. . EFF. AFUE STEADY STATE

40 50 60

LOW FIRE DERATE - S 70 80 Figure 2 

## INTEGRATED CONTROL SYSTEM STUDY
INDUCED DRAFT FWA FURNACE

. 1-ZONE U.S. HOUSE 70Z OVERSIZED PIT-TSBURGH WEATHERS OUTDOOR TEMP - 42F



## 74L 

# 75 e CYCLEDRATE OF 6 CYCLE RATE OF 5 + CYCLE RATE OF 4 x CYCLE RATE OF 3

6

---------------
x .........

x,



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## CYCLES PER H

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No.OF STAGES



## 40% DE TrAT^CPIJ .I

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## 1 , .'_- Z:::..' .3 4

IFR Doc. 83-70635 Filed 5-12- 83:8:45 eml

eiwwO CODE 6450-01-C 

### 4 TKER. MOSTATPERFORMANCET1MECoaSTANT OFCENTRAt.,TIVRNACE

MINVTES^ I 

## 3-4 Mu.



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