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 and

Renewable 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.

CAS-RM-79-104 COMMENT 14
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.

CAS-RM-79-104 COMMENT 14
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 0V 2-0.32H .46 (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 the

thermostat 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

CAS-RM-79-104 COMMENT 14
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 higher

because 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.

reGwired (Hi-

(Fo)Hi/LO

combined C

60 Second Hifire start

fie only) percent bad

k

(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

1371.7

CAS-RM-79-104 COMMENT 14
84

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

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70Z OVERSIZED PIT-TSBURGH WEATHERS OUTDOOR TEMP - 42F

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