AlllDE 71S350

NBSIR 87-3645

A Study of Three Measures for

Energy Efficiency of Fossil Fueled

Furnaces and Boilers

• <;•

. V .

Esher Kweller

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Environment Division

Gaithersburg, MD 20899

June 1987

Rnal Report

Issued October 1987

Prepared for: U.S. Department of Energy

QC f Building Energy Research & Development

100 Equipment Division

y 50 Iton, DC 20585

87-3645

1987

C.2

Research Inforniatioii Center

iNationai Bureau of Standards

Gaithersburg, Maryland 20899

NBSIR 87-3645

A STUDY OF THREE MEASURES FOR

ENERGY EFFICIENCY OF FOSSIL FUELED

FURNACES AND BOILERS

Esher Kweller

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Building Environment Division

Gaithersburg, MD 20899

June 1987

Final Report

Issued October 1987

Prepared for; U.S. Department of Energy

Office of Building Energy Research & Development

Building Equipment Division

Washington, DC 20585

U.S. DEPARTMENT OF COMMERCE, Clarence J. Brown, Acting Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
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ABSTRACT

The effectiveness of three measures of energy efficiency for furnaces has

been demonstrated by comparison of the results for predicted energy savings

against the cost savings predicted by the calculated total annual cost of

operation using DOE test procedures. Two of the efficiency measures

currently prescribed by DOE - the Annual Fuel Utilization Efficiency (AFUE)

and the DOE Energy Factor (EF) are compared with an industry proposed energy

factor - Seasonal Energy Utilization Factor (SEUF)

.

Various parameters which affect the SEUF factor have also been demonstrated.

These include the effects of power rating (wattage), burner input rating,

electric to fossil fuel cost ratio, and the effect of annual fuel

utilization efficiency (AFUE)

.

Key Words: annual efficiency; boilers, combustion equipment, efficiency,

furnaces; operating costs

iii
TABLE OF CONTENTS

Page

ABSTRACT iii

LIST OF TABLES vi

LIST OF FIGURES vii

1.0 BACKGROUND 1

2.0 SCOPE 2

3.0 RESULTS 3

3.1. Comparison of Savings Predicted by Three

Measures of Energy Efficiency

(AFUE, SEUF, and DOE EF) 3

3.2 Effects of Variables in Calculation for

Seasonal Energy Utilization Factors (SEUF) 4

4.0 DISCUSSION OF RESULTS 4

4.1. Energy Savings -Efficiency Factors

Versus Operating Cost Savings 4

4.2 Parametric Analysis of SEUF Calculations 5

4.2.1. Effect of Power Rating (Watts) 5

4.2.2. Effect of Burner Input Rating

and Modulated Burner Input 5

4.2.3. Effect of AFUE Rating 6

4.2.4. Effect of Electric to Fossil

Fuel Cost Ratio (RC) 6

5.0 CONCLUSIONS 6

6 . 0 REFERENCES 7

APPENDIX A Basis of Calculating for Comparing

a Furnace Equipped with Single Stage Control

Versus Furnace with Two Stage Control 8

APPENDIX B Calculation for Minimum and Maximum

Heated Area of Homes 10

APPENDIX C Example Calculation for Annual Operating

Cost, SEUF, and DOE EF (Based on National

Average Values for Weather and Energy Cost) 11

APPENDIX D Data Used to Calculate Operating Costs 12

iv
Page

APPENDIX E Average Residential Prices for

Utility (piped gas), Electricity and Fuel Oil,

U.S. City Average and Selected Areas 13

APPENDIX F DOE 1984 Response to Proposed Adoption of

Seasonal Energy Utilization Factor - Federal

Register Notice of March 28, 1984 14

V
LIST OF TABLES

Pa^e

Table 1. Comparison of Savings by Three Measures of

Energy Efficiency (AFUE, DOE EF, and SEUF)

and by Annual Cost Savings 15

Table 2. Annual Operating Cost and Efficiency Factors

for Selected Cities from Minimum to Maximum

Cost Ratios 15

Table 3. Data Used in Calculating SEUF, DOE EF, and

Total Annual Operating Cost 16

Table 4. Electric to Fuel (Natural Gas) Cost Ratio on

Cost Data for $/500 kwh and $/100 Therm 17

Table 5. Comparison of Savings Determined by Three Methods

(AFUE, SEUF, & Cost of Operations) for Single Stage

vs. Two Stage Furnace Control 18

Vi
LIST OF FIGURES

Page

Figure 1-9: Seasonal Energy Utilization Factors (SEUF) and

DOE Energy Factors vs. AFUE for Electric to Fuel

Cost Ratios (RC) from 1.5 to 9.0 and for Burner

Input Rating of 50,000; 100,000; and 150,000 BUT/hr . . . 19-23

Figures 1-3: For Power Input Rating of 400 Watts 19-20

Figures 4-6: For Power Input Rating of 650 Watts 21-22

Figures 7-9: For Power Input Rating of 800 Watts 22-23

Figures 10-21: Seasonable Energy Utilization Factors (SEUF)

and DOE Energy Factors vs . Furnace Power Rating

(Watts -EE) for Annual Fuel Utilization

Efficiencies (AFUE) from 60 to 95% and for

Electric to Fuel Cost Ratios (RC) from 1.5 to 8.5 . . 24-35

Figures 10-13: Burner Fuel Input of 50,000 Btu/hr 24-27

Figures 14-17: Burner Fuel Input of 100,000 Btu/hr 28-31

Figures 18-21: Burner FUel Input of 150,000 Btu/hr 32-35

vii
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II
1 . 0 BACKGROUND

Currently, the Annual Fuel Utilization Efficiency (AFUE) rating for fossil

fueled furnaces and boilers is a measure of fuel use and does not include

the secondary electric energy used to operate fans, powered burner, etc.

With conventional furnaces of moderate efficiency, the electric energy was a second order effect and was not considered necessary in the calculation of

AFUE in order to have a consistent rating method. The electric energy cost

is, of course, included in the calculation of annual operating cost. Since

the efficiency measure is the dominant measure presented to the consumer

(e.g., FTC labeling), a comprehensive study of the extent of misinformation

caused by AFUE comparisons is needed. The National Bureau of Standards

(NBS) and the Department of Energy (DOE) staff have been aware of possible

inconsistency that can exist with the newer higher efficiency furnaces that

now use less fossil fuel energy but more electrical energy. This would be

particularly true for furnaces that modulate the fuel since the fan operates

over a longer period.

Comments on this issue were received in 1983 by the DOE in response to

proposed rule making published June 17, 1983 [1]. An analysis of those

comments was prepared by NBS [2]

.

The DOE response was published in March

1984 [3] and is also included in Appendix E. The comments received on this

subject related to a substitute for AFUE or a revised AFUE and was referred

to as a Seasonal Energy Utilization Factor (SEUF) . The equation for SEUF

proposed by industry members and the Gas Appliance Manufacturers Association

(GAMA) is as follows:

_ (EF)(AFUE) + EAE (100)

(EF) + (RC)(EAE)

where

:

(3.413) (EE) (EF)

(Q) = EAE

EF = Annual Fuel Energy (Btu)

EE = Wattage Rating (Watts) as measured

Q = Burner Fuel Input (Btu/hr) measured

EAE = Heat Equivalent of Annual Electric Energy (Btu)

RC = Ratio of Electric to Fossil Fuel Cost Per Btu of Energy =

$ per Btu (electricity)/$ per Btu (fossil fuel)

AFUE = Annual Fuel Utilization Efficiency (%)

3.413 = Conversion Factor Btu/hr per Watt

Industry also commented that the DOE Energy Factor does not adequately

address this issue since the relative costs of electric to fossil fuel

energy (RC) are not included. The equation used to calculate the DOE Energy

Factor (DOE EF) is as follows:.

1
DOE EF =

(EF)(AFUE)

(EF)+(EAE)

where: EF, EAE, and AFUE are as defined above.

2.0 SCOPE

This report addresses the following three questions:

o First, how well do the current DOE procedures for energy measures

compare within themselves? That is, how well does AFUE and EF

compare as a reference for comparison with the calculated total

annual cost of operation (for electricity and fuel) as prescribed

in the DOE procedures?

o Second, how well does the Industry's proposed SEUF method compare

over a wide range of electric to fuel cost ratios with the DOE

procedures for calculating total annual cost of operation?

o Thirdly, how does SEUF compare with AFUE over a wide range of the

operating parameters which affect the SEUF? These parameters

include electric to fossil fuel cost ratio (RC) power input rating

(watts), and burner input rating (Btu/hr)

The SEUF is dependent on electric energy consumption (EAE) which is

dependent on the power rating (EE) and the annual hours of operation. The

term:

EF

(Q)

gives the annual hours of burner operation needed to consume the annual

energy (EF) , where Q is the maximum burner input rate. Furnaces with

modulated burner operation would use an average (Q) to estimate the hours of

operation. The effects of burner input and modulated burner input control

is an important aspect of this study and is discussed in Section 4.2.2 and

Appendix A.

The product of power input EE and hours of operation is the kilowatt hours

per year required. A multiplier of 3.413 converts electric energy to Btu

equivalent which is the term EAE.

Since burner input rating (Btu/hr) and power rating (watts) are parameters

in the calculation of SEUF, the calculations for this study included a range

of wattage ratings which represent the lowest (400 watts) and highest (800

watts) that were determined by laboratory test to be typical of conventional

and high efficiency furnaces, respectively. A range of fuel input rates of

50,000 Btu/hr to 150,000 Btu/hr covers the most typically used furnaces or boilers for single family residences. If an oversize factor of 70% were

assumed, the range of design heating requirements that applies with steady

2
state efficiency from 75% to 95% would be a minimum of 50,000 (0.75)/(1.7) =

22,058 Btu/hr to a maximum of 150,000 (0.95)/(1.7) = 83,823 Btu/hr.

The size range of homes that these reported results would apply to could be

calculated given the home heat loss and the design temperature. Appendix B

shows a calculation procedure used to show that with 50,000 to 150,000

Btu/hr input this ranges from 1384 sq ft to 5262 sq ft when the outdoor

temperature is 0°F and the heat loss is taken as 10 Btu/sq ft/® day.

3 . 0 RESULTS

3 . 1 Comparison of Savings Predicted bv Three Measures of Energy Efficiency

(AFUE. SEUF. and DOE EF^

The most important aspect of an energy efficiency measure is how it compares

in its determination of energy savings versus the savings determined by

calculation for annual operating costs. Without having the numbers for

total annual operating cost the consumer should be able to use the

improvement in energy efficiency to predict what the dollar energy savings

would be. This energy savings can be determined as a fraction from the

relationship

:

Savings - 1 —

AFUE

AFUE

111

( 2 )

Where (1) and (2) refer to the low and high efficiency units being

considered.

In order to evaluate the current DOE prescribed measures of energy

efficiency (AFUE and DOE EF) as well as the Industry proposed SEUF factor,

the energy savings predicted by these efficiency measures were compared to

the dollar savings found by the DOE procedures. The later measure (total

cost of fuel and electricity) was considered to be the most accurate measure

and all other energy savings by an efficiency measure are compared to it.

In the DOE procedure, heat from the furnace blower is considered in reducing

the heat which the furnace must provide. Energy savings determined using

SEUF and the calculated savings based on annual cost should be identical by

definition. In order to quantify the potential error in using the AFUE, a comparison was made between a conventional furnace efficiency of 70% AFUE

(i.e. atmospheric burner design with electric ignition) with power rating of

400 watts and a high efficiency (condensing t3rpe) furnace having 95% AFUE

and power rating of 650 watts. In order to maximize this potential

difference between AFUE and SEUF the high efficiency furnace was also

evaluated using the maximum known wattage rating of current condensing

furnace design (i.e. 800 watts). A design heating requirement (building

heating load) of 40,000 Btu/h was selected as a base case for the National

average weather conditions of 5200 degree days, 5®F design temperature, and

corresponding heating load hours of 2080. Specific design heating

3
requirements for the same building located in three other cities were

calculated by correcting the 40,000 Btu/h design heating load to the design

temperature for each city. See Appendix C for example of calculations. In

this way the same size house is compared for all cities. Burner input rate

at each site is based on the calculated design heating requirement using a constant 70% oversize factor.

Table 1 shows the results of energy savings calculated by the three measures

of energy efficiency investigated (AFUE, DOE EF, and SEUF) and the savings

determined by annual cost of operation using the DOE test procedures to

calculate fuel and electricity annual costs.

Table 2 shows the results used for calculating the savings shown in Table 1.

Table 3 shows the data used for calculating the results shown in Table 2 for

each of these four sites. These cities vary from the minimum to the maximum

known cost ratios (RC) applicable today. Table 4 shows cost ratios for

major cities in the United States as of August 1986.

3 . 2 Effects of Variables in Calculation for Seasonal Energy

Utilization Factors (SEUF)

Two formats of results are presented in Figures 1 through 21 for comparisons

of AFUE with SEUF and DOE EF. Figures 1 through 9 highlight the effect of

energy cost ratio for specific furnace ratings, i.e. in terms of power

rating and fuel input. These figures cover three selected power ratings

(400, 650 and 800 watts) for the selected burner input ratings. Cost ratios

(RC) in the range of 1.5 to 9.0 in increments of 0.5 were used with each of

three burner fuel input ratings of 50,000 Btu/hr; 100,000 Btu/hr; and

150,000

Btu/hr. Figures 10 through 21 show more explicitly the effects of

power ratings over the range of 300 to 800 watts in increments of 100 watts

4.0 DISCUSSION OF RESULTS

4 . 1 Energy Savings -Efficiency Factors Versus Operating Cost Savings

In all cases as shown in Table 1, the AFUE somewhat over predicts energy

savings (the amount depending on the RC value) compared to the savings

calculated by annual cost. For a U.S. city average cost ratio of 3.8, and

with the national average heating load hours, the AFUE over predicts savings

only slightly (i.e. 26.3% versus 22.9% and 21.1%) as shown in Table 1. This

amounts to only an error of $6.00 per year in cost savings. Table 1 shows

the departure between AFUE savings versus annual cost savings is greatest

when the electricity to fuel cost ratio (RC) is greatest. (i.e. greatest

difference exists for Chicago where electric cost is greatest [13/ per kwh]

and over predicted savings by AFUE amounts to $44.00 per year.)

These differences between AFUE and cost savings detailed above apply only to

the example chosen here for comparison. This example uses a conventional

atmospheric furnace compared to either of two high efficiency condensing

furnaces which use either 150 watt or 400 watt more electrical power. These

4
are considered to be realistic examples for comparison purposes, and were

chosen to show the improvement to be expected for SEUF versus AFUE. This

power rating of 800 watts was found previously in tests of condensing

furnaces at NBS (9). For the typical input of 80,000 Btu/hr a more typical

high efficiency condensing furnace would have a wattage rating of 150 watts

above that of the conventional furnace with atmospheric burner (8)

.

Appendix A shows that AFUE for two stage or modulating burners will result

in a more over predicted energy savings, and SEUF will allow for

considerable improvement over AFUE for that t3rpe of furnace (see 4.2.2 for

details)

.

4.2 Parametric Analysis of SEUF Calculations

4.2.1 Effect of Power Rating (Watts)

In Figure 1 we see that a furnace having a 60% AFUE rating, with a 400 watt

power rating and with, for example, the U. S. city average cost ratio of

4.0, results in 3.4 percentage points difference between SEUF and AFUE (i.e.

at 60% AFUE, SEUF = 56.6%). This difference increases to 7 percentage

points at AFUE of 95%. At 800 watts rating (Figure 7), this difference

increases from a 6.3 point difference at energy cost ratio of 4.0, and 60%

AFUE, to a 12.5 point difference at 95% AFUE. The maximum difference

between AFUE and the DOE energy factor is 2-3 points difference at 400 watts

(Figure 1) and approximately 5 points difference at 800 watts (Figure 7)

.

Cost ratio has no effect on the DOE EF (see Section 1.0).

Increased electric power would result in reduced fossil fuel energy needed

since the fan energy used is transferred to the conditioned air as heat.

Current DOE test procedures do recognize this effect in the calculation of

burner operating hours and cost of operation.

An examination of the equation for SEUF in Section 1.0 reveals that annual

fossil fuel energy (EF) is in each term of the numerator and denominator and

therefore (EF) cancels out in the calculation for SEUF. This also applies

in the calculation for the DOE energy factor.

4.2.2 Effect of Burner Input Rating and Modulated Burner Input

The burner input rate affects the hours of operation needed to provide a given amount of energy. Therefore, the lower input rate results in more

operating hours and consequently more electric energy use and lower SEUF.

The effect of modulated burner operation can be seen in Table 5 . For the

basis of calculations used to obtain these results see Appendix A. These

results show the effect of a five percentage point increase in AFUE coupled

with the increased electrical energy required for two stage operation (i.e., a doubling of the fan run time) . These results show that the SEUF as a measure of efficiency savings is identical with annual cost of operation

savings, (any small differences are due to rounding in calculations). These

results show that for the two stage controlled furnace (or step -modulating

furnace) the AFUE comparison with single stage furnace can be a misleading

indicator-or energy savings especially in areas with high electric to fuel

5
cost ratios (i.e. , the AFUE predicts a +6.6% savings for Chicago where

annual cost savings is calcualated as minus 3.3%).

This effect of burner input rate is also apparent in comparing Figure 1 with

Figure 2 and Figure 3. These figures can also be used to see the effect of

burner modulation. For example if a furnace rated at 100,000 Btu/h; AFUE

75%, and 400 watt power rating is equipped with modulating control such that

burner input averages 50,000 Btu/h with same AFUE of 75%; the SEUF drops

from 72.4% (i.e. Figure 2 with AFUE - 75%, RC - 4.0) to 70.1% (i.e. Figure 1

AFUE = 75%, RC = 4.0).

4.2.3 Effect of AFUE Rating

Lowering AFUE rating has a similar effect as reducing burner input rating

since the burner operating hours is a function of the furnace heat output

which is the product of burner input and operating (steady state)

efficiency. In general AFUE is directly related to steady state efficiency.

4.2.4 Effect of Electric to Fossil Fuel Cost Ratio (RC)

Energy cost varies mainly with geographical location but also with usage and

with time. Energy cost used is the analysis of Appendix A were obtained

from 1984 data reported by the Bureau of Labor Statistics [4] . A more

recent report of energy costs is included here in Appendix E. (See Appendix

E for energy costs for 28 metropolitan areas of the U.S.) The U.S. city

average cost ratio (RC) for August 1986 was 4.1 which is based on $60,078

per 100 therms of gas and $42,157 per 500 Kwh. (See Table 4.) Energy cost

ratios (RC) for 23 cities (Table 4) shows a wide range of values (i.e. from

8.2 for Chicago to 1.8 for Seattle. These data for U.S. cities show that

the range of costs for electricity is wider than for natural gas. Gas cost

ranges from a low of 41% below the U.S. city average (i.e. for Houston), to

a high of 52% above the average for New York City. . Electric cost ranges

from 50% below the U.S. City average in Seattle to 73% above the average for

Chicago

5.0 CONCLUSIONS

Results of this study have shown that the efficiency measure, SEUF which

includes the electric energy and its relative cost with respect to fuel cost

(RC) would provide for an accurate reflection of the total energy cost

savings, and is therefore a better measure of efficiency than the AFUE or DOE EF. The most significant improvement in the application of the SEUF

factor over AFUE is expected for furnaces or boilers having modulating type

burners

6
6.0 REFERENCES

[1] Federal Register, Vol. 4, No. 118, pp. 28014-28046, June 17, 1983.

[2] Kweller, E.R. , "Analysis of Public Responses to Proposed Department of

Energy Test Procedures for Furnaces, Boilers, and Household Heaters,"

Letter Report prepared for Department of Energy, February 7, 1984.

[3] Federal Register, Vol. 49, No. 61, pp. 12148-12178, March 28, 1984.

[4] Bureau of Labor Statistics, "News," United States Department of Labor,

Washington, August 1986.

[5] American Gas Association, "Gas House Heating Survey," Arlington, VA,

1983.

[6] Energy Information Administration, "Housing Characteristics," p. 26,

Washington, DC 20585, August 1983.

[7] ASHRAE Handbooks -- 1985 Fundamentals and 1980 Systems, ASHRAE,

Atlanta, GA 30329.

[8] Personal Communication with L. Wethje of ETL Laboratory.

[9] Kweller, E.R. and Wise, R.A. , "Laboratory Study of Gas Fueled

Condensing Furnaces," NBSIR 85-3225, National Bureau of Standards,

Gaithersburg, MD 20899, July 1985.

[10] Kweller, E. R. , "An Analysis of Burner On and Off Periods and Their

Effect on Part- load Efficiency for Furnaces and Boilers Equipped with

Modulating Controls." Letter report from National Bureau of Standards

to Department of Energy, Jan. 1983.

7
Appendix A

Basis of Calculation for Comparing a Furnace Eauipped with Single

Stape Control Versus Furnace with Two Stage Control

Using oversize factor at design conditions as 0.7 (i.e., 70% oversize);

design temperature and heating requirement at design conditions based on

40,000 Btu/h for the national average design temperature of 5 F; and design

heating requirement for each city adjusted using design temperature for each

city. (i.e., same house construction for each city.)

Burner operating hours and annual fuel and energy costs determined as shown

in Appendix C. Burner input also determined as in Appendix C.

Specific conditions for single stage control : Burner on time is based on furnace assigned values in DOE test procedures of

3.8 minutes on and 13.3 minutes off.

Power input is assigned a value of 400 watts.

Furnace Steady State efficiency = 75%; AFUE = 70%

Specific conditions for two stage control :

(1) Same furnace steady state efficiency at both maximum and reduced input

as single stage control furnace.

(2) AFUE is increased by 5% due to the reduced cycling losses which apply

for two stage control, with burner on and off times assigned as 10

minutes as per DOE test procedures for furnaces.*

(3) Output energy required to meet heating load is the same as for single

stage furnace, consequently burner input rate at maximum input is the

same as single stage furnace.

(4) Ratio of increased electrical use is the ratio of percent on time for

each furnace (i.e., single stage - 3 . 8/(3 . 8+13 . 3) - 0.22

two stage = 10/10+10) - 0.50

Using these on time fractions the ratio of on time for the two stage

vs the single stage furnace is 0.50/0.22 - 2.27

In other words the amount of electrical energy required for the two

stage furnaces is 227% of the single stage furnace if the power rating

of each is the same. *Data used to calculated part- load efficiency and AFUE in determining a nominal increase in AFUE for a forced air furnace was obtained from testing

of a two stage forced air furnace at NBS. Results were reported in

Reference 10.

8
(5) Burner operating hours and fuel energy required for the two stage are reduced due to increased electrical energy which is credited in

reducing the house heating load.

The assignment of a power input for the two stage furnace consistent with

power input of the single stage furnace in combination with the assignments

of the ratio calculated in (4) above; and the assigned increase of 5% in

AFUE for the two stage furnace allows for using the same calculation

procedure for two stage control furnace as described in Appendix C instead

of the detailed DOE procedures which require specific information on heat-up

and cool down temperatures, etc. In this calculation the two stage furnace

is treated as a single stage furnace with a power input rating of (2.27)

(400) or 908 watts.

9
Appendix B

Calculation for Minimum and Maximum Heated

Area of Homes

Example for minimum area:

Minimum Input Rate - 50,000 Btu/hr

Minimum Efficiency - 75% (Steady State Efficiency)

Minimum Heated area for heat loss of 10.0 Btu/sq ft/®day* and with

outdoor temperature of 0®F

Degree days with 0®F=65® - 0®-65

Minimum Output Rate = 50,000 (0.75) - 37,500 Btu/hr

Minimum Area =

(37,500 Btu/hr) (24 hr/day)

(10 Btu/sq ft/®day) (65®days) = 1384 sq ft

Maximum area with this same heating load is:

Maximum Output = 150,000 (0.95) - 142,500 Btu/hr

vr • A 142,500 (24) _ Maximum Area ** — - 5,262 sq ft

(iU) (b5)

The value of 10 Btu/sq ft/® day is considered to be consistent with

energy consumption for gas fueled homes. The latest American Gas

Association Household Heating Survey [5] reports annual fuel use for

central heating as 75.6 x 10° Btu per year. If the national average

for heating degree days is taken as 5,200 ®days. The average area for

a home is calculated from:

(A) (10 Btu/sq ft/®day) (5 , 200) - 75.6 x 10^ Btu

A - 1,512 sq ft

This area is considered representative of U.S. single family housing

characteristics as reported for 1981 [6}. The mean number of sq ft of

heated area ranges from 1,271 sq ft to 1,826 sq ft depending on the

type of home.

10
Appendix C

(A) Example Calculation for Annual Operating Cost. SEUF and DOE EF (Based

on National Average Values for Weather and Energy Cost^

Given: AFUE = 95%; ss - 95%; DHR - 40,000 Btu/hr or KDHR =« 40

(FE+BE) = 800 watts - power rating; oversize (a) — 70%; HLH — 2080

(electric ignition) AFUE - Rc - 4.1 - U.S. city average

(1) Determine Burner input rate (Qin)

TMjn _ Qin (nss) . (1.7) (40,000)

(1 + a) ’ 05

Qin - 71,578

(2) Determine Burner Operating Hours (BOH):

BOH = 2080 (0.77) (A) (KDHR)

1000

3413 (EE) + Qin

where A

100,000 0.014

3413(0.8) + 71578(0.95)

BOH =911 Hrs

(3) Determine EF (Fuel Energy)

EF = BOH (Qin) - 65.2 x 10^ Btu = 652 therms.

(4) Determine Electric Annual Energy (EAE)

EAE = BOH (P) - 911(0.8) - 728 kwh

(5) Determine SEUF (See equation in Appendix A)

SEUF= 65.2 X 10- (0- 95) „ + 728 ( 341_3) . 33

65.2 X 10^ + 4.1 (728) (3413)

(6)

Calculate Annual Operating Cost

Based on National Average Cost of 61.1^ /therm and 8.0c /Kwh

Fuel Cost = 652 therms ($/ 0.611 therm) - $398.37

11
(7) Determine DOE Energy Factor (DOE EF) from equation in Appendix A.

DOE EF = fOO

EF X AFUE

EF + EAE

= 100

65.2 X 10^(0.95)

65.2 X 10^ + 728 (34.3)

91.5%

(B) Example of Recalculated Design Heating Requirement (DHR)

o Design temperature (TD) for Seattle is 26®F (See Table Below)

° Correct U.S. City Average value of 40,000 Btu/hr DHR (1) at TD of

5“F to Seattle, DHR (2) as follows:

DHR (1) _ Td^ _ 65-5

DHR (2) T(2) 65-26

DHR (2) - 40,000 (39) - 26,000 Btu/h

(60)

Appendix D

Data Used to Calculate Operating Costs

City Days Design Heating Cost (^)

Temperature Load Hours Gas Elect.

©F (Therm) (Kwh)

U.S. National 5200 5“ 2080 61.1 8.0

Average

Seattle 5145 26" 3166 64.8 4.0

Washington, D.C. 4224 17 2112 74.4 7.9

Chicago 6639 -4 2309 46.9 13.9

12
APPENDIX E

AVERAGE

RESIDENTIAL

PRICES

FOR

UTILITY

(piped

gas)

ELECTRICITY

AND

FUEL

OIL

U.S.

CITY

AVERAGE

(VJ

<0 IS. (SI fS.O (^0'(SI

A

m AOi-H O A r-.oio o (SI (SI m O' A A CMni-HO' 'S'lor'.m ID CO fs. Ah- A (SI n- AM r'-r-. Ar-.rs. A A m fs. Afs. Ais-rs. IS. A •VO • << . . . .< < << < • • <

(»M o z zz z z zz z 2

30' <iH

#H mm O A i-Hrs.'3m |S.< AO O'

m o 00

m in in

"0 o (.

m (SJ

A mom'3 IS. o o in

m r-i in A'3 0 3 « Is- A A A h- O' A r-.r-. fs-r^ Ar'. Is. A AAA r>. A +* u. a >A • < << < < o <M A e z zz z z zz z z 0 30' </y

•DCm ^ f<9 ^

in mo'p^oin c rH (SI rH m '3 O'

0) •A • (U 0 OlA (SJ

A Ain >3 (SI u i. >* z 30' '3 A'3 '3 Am c 0 +» S <»

Q) > •rt 0 U

•H o

0) > 1. o

<4-1 4» +>

m

<D •H

U

A o o m in rH u 0 L m o'3oom « O' Am'3 0' • iU 0. >*A • E in ^ A (M m A m m (SI 0 • 30' >3 A<'3 Am 3 ”3 i-t «>

r- h- 'T lo >3- 00m O' »n 00 (\i 'T >9’ oo 'o '3* cm oo oo

K)<3-in'3'rO»0'3’»0'3'»0

'000'Or<«.rOOrOO'NCNiOO(M

'3''3‘iHO’'O'3’00t0NOO'lf»r^fO

C0IT|irt'0’(SI>0'3'O'3’l0v0O»0

r«.^o(sieorMrs.foir

'3'0"3’(MOnOOi-I»0'000

K)'0'3‘0MT|O'r«.r-l|s.rs.

•o '3- ^ lo >T '3' K) '3- (SI

m in iH lo tn^ir\to*ntn<a‘tn^tn

M-4Co

+j

03U

0) O «3

4-

•oCo wEL

tt X

01 OO 30'

<1-1 </>

lHooin^^.(^ oooo(Mo«3‘r«.eoooomo'

i-i

m (\j o O' »oin'3-foo-'3-'o(simi'^(sicsi'3‘ iH(si(Sii^O' >o ^3* O' O' K) K) <o r«> 00 '3' i-i 00 'o'oeo'oom'oeinor>>eosoor>i'30»no'

oo»h'>rN.'3’r'.(Niinino r^oor>>oOfH m '3 O' (Nj ^ m m rs. o '3* OO VO ^3* (Mr^o'3'oooo'inom

o'inr'.r'.rw »n vo 'o

mmm >o «o vom >o tn 'o >omm i-im rom 'o 'O

»4-; O

4JWou

4» o m

mmm

A O' o e O '3 (SJ o '3A o A

m fs.

A

m e o e o O'm

m

.H

W (SI

m

A (SI (SJ O'

m

A fH '3 '3-

m

A (SI o m (SI (SI IS. O'A (SI O' e rs

N

A O' O' o a O' (SI '3 (SI o O' A IS. o O m rs <3 IS. o m pH rs A O' pH A m >3 A pH (SI O' o

•ri a L. >A • L 0 rH A IS. n- O'

m '3 O'

m

A

m IS. (SJ IS.

AA

m pH

m (SI (SImm O'^s, e m 4» a 3(^ m '3 m r-. rs rs m A A m m m A A A m A m A A A m S3 '3>tn m A A O o “>I-H </> pH w o A'3m'3rH oooN.AarHmAm30'(Sj rsO'omoomo'Am

(0 >»A 3 m (SI o in AAAomoo'Arnc'O'mm 3rHArHAOfH30'm

01 4» (SI m(siO'(siisi 0'Amrs.^..^-^mtnmc^'S!|s.|s. C^AAOrH30'000

•H •A • PN W OlA A oo> Amc

A O' rH

m n V3 :-0 C ' C?

m

A rH AA(SJi-IOO'A'3mO>

(U 0 •H E 30' (SI (si(si(simm rH >.M

m f (S' rjcjTJ f-.!fjrjr>jm rSI(SI(SI^SlmrHrH^JmrH 0 4^ L. <1-1 «>

10 a 3 «

•H X fH a +» 3 w u O

>1 '3 |s- (simm3rH o o a (c *c -5 _i tn a m -3 O' o r.. -3 o m o o A a rH in

4'

A i-t 3 (SI

A

m

A

A O'

m

m o ''s o a u> rsm 'O •)

A (SI (SI

AA fO 'A rH

m

•H i. O' 3mO'3(SJ O' O' o fs. IS.

A

mm o t?> fs.m 0'mArH^s.3A^s<^0 u O >»A • •H a rH 00 m omAmo AO'OmmAAO'AAmArH AO'moO'rHA3(SJO' 0

4* 3(^ (SJ (sj(si(sjmm rH(sjm(sj(si(sj(sj(si(si(sinj(sim (SJ(SJ(SI(SJ3('JrH(SJmrH - •nrH O' LO

0) 4-

to • • • • • • ••••••• • • • W • • • • • • ••••••• • • • « O • • • • • • ••••••• • ‘N u N • • • • • ••••••• • • •H •H • • • • • •••••••

4J L w • •4- • • • • • lO a T3 ••H • • • ••••••• • • w Q c C •rH • • ••••••• • ••ri • • wH o t-l • a • • . . . ^ . • ••••••• • •4- 0 •H .(J-> . * * * * • ••••••• * * 1 •«H

•H +» C • • • • ••••••• • • •rH

4» (D L. • sZ . • • • • • • • V • • • N • a C pH « • E • • **0 N . •(VJ|'^ . •('J| • •(SJ|C •o 0 3 4* ••H C . . . C(S| (sj| • • a • • • • • •H

T3 a W • a c • . . .|H • • a • • •> • • • xs

•rt o 01 • X a-> • • • 1 • • • -H • • • X 1 ' • • • ami • w •0 w 0. w s 2 . (04* • N • • • O • • CX \ w • • • •“ • C S • c 0 W H X • c wz (H • • • • a w '(S4 aT) ... V, • a»H • a L •D (0 +» •< a 1 . o •N. > arH sz ... «(S|| •^ 3 •rH CrH O L « . a • • 1 o • nj|rH S »H • 1 . . .X . 1 o •JiC 0 (D u 01 O • sx a ^ . . o • > 1 m4- s • • S. • 4^ *H . .Q_ a

01 a Z X4'Q.

W ‘’H S • • W • 1 •H4»0 s (SH o c-H . o • • o O c 1. 1 • O 1. a • X c • W C 01 •rH4> • (sji >H o a S4^ a 1 L O O • X a o s rHTJ *o a • •H c a o a ao •XS 2 • mo. o O •H > pH u az a <Z W *D 2 a LSU i. •>-o a X s 1 u > 0) m •ha I >H W srH • qlo a s a • 4^Z a >1 w s w ao

L. < tn - IS

—

oi>- a ^ c

04> OZ O

Ol'H-l *D a o I « o U L « **H X « • «x UO-JZQ. 0 o

01 (.

(0 O C E

O'H X-H C (0 <03

lO'H 3 a S-H

(D Al^ C I ecu*'

O'H O'H H O > E

VI C C (0 O-H « AOOS

O-H ^ V)

d) WD'H ^ (D C 3 3 « 10 O

(DX*-4_J

•-I (. L • •H O 0 4^ szeutn

•. > C OZ » L H>4^'HX'H OUiO 'DO" 'HiHOlU

0)14* "•'CU.3«'U01.C

0)001 OOOI^C 0.30 •H^C 4*^^V)30IA0XL.

O-H-H COOO^>HOOV)li.

4*X 04- O M (0 C+» COW ^4- m<~i C 3 C C-H C

ooo 4’3^0000*H-H0

(n(/)3 < AOQzz)^SQ.(n

Note:

To

calculate (

RC)

multiply

electricity

cost

per

500

KWH

by

5.8

and

divide

by

gas

cost

per

100

therms

of

utility

(piped)

gas.

For

oil

multiply

electric

cost

per

500

KWH

by

0.082

and

divide

by

cost

per

gallon

of

oil.
APPENDIX F

DOE 1984 Response to Proposed Adoption of Seasonal

Energy Utilization Factor

Federal Register / Vol. 49, No. 61 / Wednesday, March 28, 1984 / Rules and Regulations

4. Energy Efficiency Descriptor

Although not directly related to any of

the issues raised in the June 17 proposal,

many commenters discussed the need

for an energy efficiency descriptor

(energy efficiency rating) to account for

the electrical energy used by a fossil fueled furnace in addition to the fossil fuel used. The descriptor AFUE only

accounts for the fossil fuel efficiency.

See TRD, No. 7, at 1; Carrier, No. 10, at

1; and GAMA, No. 12. at 8. The

proposed provisions for modulating

controls drew these comments since in most modulating designs improved fuel efficiency (AFUE) is obtained at the expense of additional electrical energy

consumption, (e.g. increased blower run

time). The existing regulation for determining annual operating costs does

reflect this concept, since electrical and

fuel costs are separately determined and

then summed. The commenters felt that

in addition to the annual operating cost

provisions, an energy efficiency

descriptor needs to be added that will

fairly disclose to the consmner the

relative performance of different designs

of furnaces that use both fossil fuel and

electricity. Commenters felt the situation

is exacerbated by FTC’s labeling program, where for furnaces the dominant disclosure is AFUE and"

annual operating costs are relegated to the bottom of the Fact Sheet in grid format. The consumer may make a purchasing decision solely on the AFUE

and not consider the electrical cost as

well. Carrier delineated an example of

the misleading nature of comparisons*

based on AFUE by showing where a

’ higher AFUE furnace had an actual higher annual operating cost. See

Carrier Corp., No. 10, at 2. Obviously.

. this outcome was dependent on

adrained relative costs of the fuel and

elf^tricity. Other relative costs

V 'asetimtltiQns could lead to the opposite

• outcome, i.e., higher AFUE, lower

- operating costs. The commenters

' suggested the adoption of a new

efficiency descriptor that includes an ovemge electricity to fuel cost ratio. Any rankings developed from this descriptor %spuld be identical to that developed on the basis of annual

operating costs using the same average

electricity to fuel costs ratio. EMDE sees some merit to an efficiency descriptor

based on the average electricity to fuel cost ratio but feels there exists, already

in DOE procedures, a superior method of

rating a furnace’s performance in ail costs scenarios, not just average costs

scenarios. The DOE procedures

currently provide the method of

calculation needed to explicitly detail the electrical energy cost and the fuel energy cost for any furnace. Therefore, for the reasons discussed

above today’s final rule does not include a new energy efficiency descriptor.

However, DOE will continue to examine

this subject and may consider revisions

at a later date.

12151

14
Table 1. Comparison of Savings by Three Measures of Energy Efficiency

(AFUE, DOE EF, and SEUF) and by Annual Cost Savings for increase

in AFUE from 70% with Power Rating of 400 Watts to AFUE of 95%

and Power Ratings of 650 and 800 Watts.

Location AFUE Power Savings (%) Determined by:

(Cost Ratio)* % Rating AFUE DOE EF SEUF** Annual**

Cost

U.S. City 70 400 . _ _ _ Average 95 650 26.3 25.1 22.9 22.9

(3.8) 95 800 26.3 24.6 21.6 21.1

Seattle 70 400 _ • 95 650 26.3 24.6 24.4 24.5

(1.8) 95 800 26.3 23.7 23.9 24.0

Washington 70 400 - - - - 95 650 26.3 25.7 23.0 23.1

(3.1) 95 800 26.3 24.3 21.9 21.9

Chicago 70 400 - - - - 95 650 26.3 25.3 19.2 19.1

(8.7) 95 800 26.3 24.9 16.1 16.1

*Cost Ratios determined using Appendix E. - averages for all households.

**Any difference in percent savings between SEUF and Annual Operating Cost

is due to rounding in the calculations.

Table 2. Annual Operating Cost and Efficiency Factors for

Selected Cities from Minimum to Maximum Cost Ratios.

Location

Power

Rating AFUE EF SEUF Annual Cost $

(Cost Ratio) Watts % % % (Total Fuel & Electric

U.S. City Average 400 70 69.0 67.6 $579.06

(3.8) 650 95 92.1 87.7 446.42

800 95 91.5 86.2 456.61

Seattle 400 70 68.4 69.4 592.10

(1.8) 650 95 90.7 91.8 447.00

800 95 89.7 91.2 450.10

Washington , D . C

.

400 70 68.7 67.9 596.97

(3.1) 650 95 92.5 88.2 459.39

800 95 90.7 86.9 466.49

Chicago 400 70 69.1 64.0 599.10

(8.7) 650 95 92.5 79.2 484.43

800 95 92.0 76.3 502.66

15
Table

3.

Data

Used

in

Calculating

SEUF,

DOE

EF

and

Total

Annual

Operating

Cost* o o 00 OV ov O <n VO VO CM o Ov <n •o vO o •o VO

CO • • • • • • • • • • • • •u <n- CM r- o vO ov vO OV St CM ov VO VO O ON m o\ IT> vO OV 00 O m H •4- lO •o St in St m m •4

>v00 -u o CM «4 CM

m vo 00

m o •4 4 M OS 00 m CM O St CM ^ 00 vO 4 CM

OJ o <o- d u cn

m cn CO ov O CM 00 H CM m 4 CO 4 vO vO OV rH CO 4 m u

•H

<9

U d U in 00 00 VO CO o OV in CO 00 d U » ov 00 00 CM VO 4 vO o ov ov CM d (U ^ m 00 o 4 vO r». 4 vO 00 CO in o 00 4 in 4 CM 4 m vO 00

4J CO 4 Ov ov ov CM ov

m CM 4 ov CO

0) CB d O CO- 00 vo CO OV vO r-' CM o rs 00 00

(Bl

U vo O vO O O CO ov ov 4 ov ov

in 4 4 in 4 4 m cn CO in CO CO «

CO e d Wi

m 00 00 vo r- CM vo CO CM d 0) r- CO CM in m 4 co CO Ov in in d X 00 vO vo p» m in 00 00 00 vo vO H

00d M *H CO 0) 4J M r>- VO

m CO 4 o 00 CM d CO 0 00 vo m 4 vo m o 00 •H ^ Ki O 4 CO ro O ov ov o o ov OV ON d 0) 03 m a

•H o VO

00^>

M d a

0) 4J O o o o O o o O o o o o > 4J 4-1 O in o o in o o in o o in o o CO CO 4 vo 00 4 vO 00 4 vo 00 4 vo 00

cu Pi

CO vo vo CO CO CO fs. vo vO ps ov ov d CO CM CM CO vO vo vo vo ps fs

•rC d ov

m in in CM CM CM CO CO vO in in O' 00 vO vo CM IS. n- 4 CM CM o »H ^4 m in 4 4 in in O 00 00 ov rs IS. do

•H o O O o o o o o o o o O 44 Pi o o o o o o o o o o o O CO ta d o o o o o o o o o o o o rS Q 4J vo vo vo CM CM CM vO vO vO o o o d

PO CM CM CM CO CO CO 4 4 4 4 4 4 u

r-SCOU S CO vO vO VO CM CM CM Ctv <JV OV o o o u vO vO vo r-4 r-H o O o 00 00 00 4) K US CM CM CM CO CO CO o o o f-H v^ CO ro CO CM CM CM CM CM CM CM CM CM a8

CO

U

M

da O in in O in in o in in o in

m 0) pH r-* ON ov ov ov ps ov ov ps ov ov < o • H4 u Q Q M o » d •H d d o 4J o v 4) •H CO 4J 4J Ou

4J *d Pi « 00 o •H 0) a

CQ d rS -N d 60 00 < U CO u 4J 00 •H CO rs CO 00 O CO 4J • 43 • u • • u • 4) o CO pH 00 <n •H 00 CO 0) m 4) u 0) CO 43 • > CO CO P < *
Table 4 Electric to Fuel (Natural Gas) Cost Ratio Based on Cost Data for

$/500 Kwh and $/100 Therm.* (See BLS Data Appendix E for August

1986.)

Cost Ratio

Location

(RC)

1. Chicago 8.2

2. Kansas City 7.0

3. Anchorage 6.5

4. Cleveland 6.4

5. Dallas/Ft. Worth 5.4

6. St. Louis 5.4

7. San Diego 5.1

8. New York 4.8

9. Denver 4.7

10. Detroit 4.7

11. Philadelphia 4.3

12. Buffalo 4.2

13. Cincinatti 4.2

14. Minneapolis/St. Paul 4.2

15. Pittsburgh 4.1

16. N . E . Pennsylvania 3.9

17. Baltimore 3.8

18. Boston 3.7

19. Washington, D.C. 3.6

20. San Francisco 3.6

21. Atlanta 3.4

22. Milwaukee 3.4

23. Los Angeles/Aneheim 3.3

24. Portland, Oregon 2.4

25. Seattle 1.8

U.S. City Average 4.1

* Cost for these larger amounts of energy is considered more

representative for central heating customers than average data for all

customers (i.e. Appendix E)

.

17
Table 5 Comparison of Savings Determined by Three Methods (AFUE, SEUF,

& Cost of Operation) for Single Stage vs. Two Stage Furnace Control

Table 5A

National Average Weather and Fuel Cost of

64^/Therm and Electric Cost of 8f^/Kwh

Total Annual

Control Tvne Annual Cost of AFUE SEUF Cost

Single Stage

Fuel

$547

Electricitv

$32 70.0 67.6 $579

Two Stage $499 65 75.0 69.3 $564

% Savings 6.6% 2.5% 2.5%

(Fuel

Control Tvpe

Table 5B

Chicago, IL

Cost 46.9^/Therm; Electricity Cost

Annual Cost of AFUE

13.9ji^/Kwh)

SEUF

Total Annual

Cost

Fuel Electricitv

Single Stage $538 $ 61 70.0 64.0 $599

Two Stage $492 $127 75.0 62.0 $619

% Savings 6.6% -3.2% -3.3%

Table 5C

(Cleveland, OH)

(Fuel Cost 50 . 8^!^/Therm; Electricity Cost 11.0^/Kwh)

Total Annual

Control Tvpe Annual Cost of AFUE SEUF Cost

Single Stage

Fuel

$526

Electricitv

$47 70.0 65.6 $573

Two Stage $480 $97 75.0 65.0 $577

% Savings 6.6% -0.9% -0.7%

18
Figure 1.

Seasonal Energy Utilization Factors (SEUF) and

DOE Energy Factors vs. AFUE for Cost Ratios (RC)

from 1,5 to 9.0

For Input Power Rating of 400 Watts and Burner

Input Rating of 50,000 Btu/h

SEASONAL ENERGY UTILIZATION FACTOR

\A 1 R\r ! 60 65 70 75 80 85 90 95

C\U 1 \E!

1.5 ! 60.3 65.1 69.9 74.7 79.5 84.3 89.1 93.9

2.0 1 59.5 64.2 69.0 73.7 78.4 83.2 87.9 92.7

2.5 1 58.7 63.4 68.1 72.8 77.4 82.1 86.8 91.5

3.0 ! 50 .

0

62.6 67.2 71.8 76.5 81 .

1

85.7 90.3

3.5 ! 57.3 61.8 66.4 71.0 75.5 30.1 84.6 89.2

4.0 I 56.6 61 .

1

65.6 70.1 74.6 79.1 83.6 88.1

4.5 ! 55.9 60.3 64.8 69.2 73.7 78.1 82.6 87.0

5.0 i 55.2 59.6 64.0 68.4 72.8 77.2 81 .

6

86.0

5.5 ! 54.5 58.9 63.2 67.6 71.9 76.3 80.6 85.0

6.0 1 53.9 58.2 62.5 66.8 71 .

1

75.4 79.7 84.0

6.5 ! 53.3 57.5 61.8 66.0 70.3 74.5 78.8 83.0

7.0 ! 52.7 56.9 61 .

1

65.3 69.5 73.7 77.9 82.0

7.5 ! 52.1 56.2 60.4 64.5 68.7 72.8 77.0 81.1

0.0 ! 51.5 55.6 59.7 63.8 67.9 72.0 76.1 80.2

8.5 ! 50.9 55.0 59.0 63.1 67.1 71.2 75.3 79.3

9.0 ;

\A !

50.4 54.4 58.4 62.4 66.4

DOE ENERGY FACTOR

70.4 74.4 78.5

R\F 1 C\U ! \E!60 65 70 75 80 85 90 95

ALL ! 58.4 63.3 68.1 73.0 77.9 82.7 87.6 92.5

Note. Input power rating and burner input ratings refer to

metered rates during steady state operation,

* DOE energy factors do not change with RC ratios. Values

shown apply to RC from 1.5 to 9.0 as well as all other RC

values.

19
Figure 2. Input Power 400 Watts, Burner Input 100,000 Btu/h

GEAGONAL ENERGY UTILIZATION FACTOR

\A 1 R\F 1 60 65 70 75 80 85 90 95

C\U

\E

•J. . 5 ! 60 .

1

65.0 69.9 74.8 79.7 84.6 89.5 94.4

2.0 1 59.7 64.6 69 .

5

74.3 79.2 84.

1

08.9 93.8

2,5 1 59.3 64 .

2

69 .

0

73.8 78.7 03.5 88.3 93.2

3.0 1 59 .

0

63.8 68.6 73.4 78.2 83.0 87.8 92.6

3.5 1 58 .

6

63.3 68.1 72.9 77.7 82.4 87.2 92.0

4.0 ! 58.2 62.9 67.7 72.4 77.2 81.9 86 .

6

91.4

4.5 1 57.8 62.5 67.2 71.9 76.7 81.4 86.1 90.8

5.0 ! 57.4 62.1 66.8 71.5 76.2 80.0 85.5 90.2

5 5 1 57.1 61 .7 66.4 71.0 75.7 80.3 85.0 89,6

6.0 ! 56.7 61.3 66 .

0

70 .

6

75.2 79.8 84.4 89.1

6.5 f 56.4 61 .

0

65.5 70 .

1

74.7 79.3 83.9 88.5

7.0 ! 56 .

0

60 .

6

65.1 69.7 74.3 78.8 83.4 88.0

7.5 1 55.7 60.2 64.7 69.3 73.8 78.3 82.9 87.4

8.0 i 55.3 59.8 64.3 68.0 73.4 77.9 82.4 86.9

8.5 1 55.0 59.5 63.9 68.4 72.9 77.4 81.9 86.3

9.0 1

\A 1

54.7 59.1 63.6 68.0

DOE ENERGY

72.5

FACTOR

76.9 81.4 85.8

R\F ! C\U 1 \E!

60 65 70 75 80 85 90 95

ALL 1 59.2 64.1 69.1 74.0 78.9 03.9 08.8 93.7

Figure 3. Input Power 400 Watts, Burner Input 150,000 Btu/h

GEA50NAL ENERGY UTILIZATION FACTOR

\A ! R\F 1 60 65 70 75 80 85 90 95

C\U 1 \E 1

1 5 60 1 65 0 0 59 0 64 7

2 5 59 6 64 4

3 0 59 3 64 2

3 5 59 0 63 9

4 0 58 8 63 6

4 5 58 5 63 3

5 0 50 3 63 0

5 5 58 0 62 0

6 0 57 8 62 5

6 5 57 5 62 2

7 0 57 3 62 0

7 5 57 0 61 7

0 0 56 8 61 4

8 5 56 5 61 2

9 0 56 3 60 9

70 . 0 74 . 9 79 . 0

69 6 74 6 79 .5 69 , 3 74 .2 79 . 1 69,, 0 73 .9 78.,0

60 . 7 73 . 6 78 , 4

68. 4 73 .2 78. 1 68, 1 72 9 77,.7

67. 8 72,, 6 77. 4

67 5 72 .3 77. 1 67 ..2 72 . 0 76, 7

66 . 9 71 , 7 76. 4

66 . 7 71 ,4 76. 1 66. 4 71 ., 1 75. 7

66. 1 70, 0 75. 4

65 . 8 70 . 5 75. 1 65 . 5 70 . 2 74. 8

04 . 8 89 , 7 94 . 6

04 . 4 89 .3 94 .2

04 , 0 00 .9 93 .8

03,, 6 88 5 93..4

03.,3 88. 1 92 .9

02. 9 87..7 92.. 5

82, 5 37 3 92 , 1 82. 2 87 0 91 ,.7 81 ,,8 86. 6 91 .3 81 ,, 5 86..2 90 . 9

81 . 1 85. 8 90 . 6

80. 8 85 . 5 90 . 2

80 , 4 85 . 1 89 8

80 . 1 84. 7 89. 4

79 . 7 84 . 4 89. 0 79. 4 84. 0 88. 6

DOE ENERGY FACTOR

\A I R\F ! 60 65 70 75 80 85 90 95

C\U ! \E!

ALL ! 59,5 64.4 69.4 74.3 79 3 84.2 89 2 94.1

20
Figure 4. Input Power 650 Watts. Burner Input 50.000 Btu/h

5EA50NA!- ENERGY UTILIZATION FACTOR

R\F 60 65 70 75 80 85 90 95

C\U

\E

1.5 60 . A 65.1 69 .

8

74.5 79.2 83 .

9

88 ,

5

93.2

2.0 59.2 63.8 68 .

4

73.0 77.6 82.1 86.7 91.3

2.5 58.0 62.5 67 .

0

71 .5 76 .

0

80.5 85 .

0

89.5

3.0 56.9 61.3 65.7 70 .

1

74 .

5

78.9 83.3 87.8

3.5 55.8 60 .

1

64.4 68.8 73.1 77 .

4

81 .7 86 .

1

A . 0 54.7 59.0 63.2 67 .

5

71.7 76.0 .80.2 84,4

4.5 53.7 57 9 62.0 66.2 70.4 74.6 78.7 82.9

5 .

0

52.7 56.8 60.9 65.0 69.1 73.2 77.3 81 .

4

5.5 51 .

8

55.8 59,8 63.9 67.9 71.9 75.9 79.9

6 .

0

50.9 54.8 58.8 62.7 66 .

7

70 .

6

74.6 78.5

6 .

5

50 .

0

53.9 57.8 61.7 65.5 69.4 73.3 77.2

7 .

0

49.2 53.0 56.8 60 .

6

64.4 68.2 72.1 75.9

7 .

5

48 .

3

52 .

1

55.9 59.6 63 .

4

67.1 70.9 74.6

3 .

0

47 .

6

51.2 54.9 58.6 62.3 66.0 69.7 73.4

8.5 46.8 50.4 54 .

1

57.7 61.3 64.9 68.6 72.2

9.0 46 .

0

49 .

6

53.2 56.8 60.3 63.9 67.5 71 .

1

DOE ENERGY FACTOR

60 65 70 75 80 85 90

57.5 62.2 67.0 71.8 76.6 Bl .

A

86.2

\A

R\r ! C\U 1 \E1

ALL ! Figure 5. Input Power 650 Watts, Burner Input 100,000 But/h

SEASONAL ENERGY UTILIZATION FACTOR

\A ! R\F 60 65 70 75 80 85 90 95

C\U

\E

1.5 60.2 65.1 69.9 74 ,

7

79.6 84.4 89.2 94 .

1

2.0 59.6 64.4 69.2 73.9 78.7 83.5 88.3 93.1

2.5 58.9 63.7 68.4 73.2 77.9 82.6 87.4 92.1

3.0 58.3 63.0 67.7 72.4 77.1 81.8 86.5 91.2

3.5 57.7 62.4 67.0 71.7 76.3 80.9 85.6 90.2

4.0 57.1 61.7 66.3 70.9 75.5 80.1 84.7 89.3

4.5 56 .

6

61 .

1

65.7 70.2 74.8 79.3 83.8 88.4

5 .

0

56.0 60.5 65.0 69.5 74.0 78.5 83.0 87.5

5.5 55.5 59.9 64.4 68.8 73.3 77.7 82.2 86.6

6.0 54.9 59.3 63.7 68.1 72.6 77.0 81.4 85.8

6.5 54.4 58.7 63 .

1

67.5 71.9 76.2 80 .

6

85.0

7 .

0

53.9 58.2 62.5 66.8 71.2 75.5 79.8 84.2

7.5 53.3 57.6 61.9 66.2 70.5 74.8 79 .

1

83.4

8.0 52.8 57.1 61.3 65.6 69.8 74.1 78.3 82.6

8.5 52.3 56.6 60.8 65.0 69.2 73.4 77.6 81.8

9.0 51.9 56.0 60.2 64.4 68.5 72.7 76.9 81 .

0

\A 1 R\F 1 C\U ! \E J

60

DOE ENERGY FACTOR

65 70 75 80 85 90 95

ALL 1 58.7 63.6 68.5 73.4 78.3 03.2 88.0 92.9

21
Figure 6. Input Power 650 Watts, Burner Input 150,000 Btu/h

5EAG0NAL ENERGY UTILIZATION FACTOR

\A ! R\F 60 65 70 75 80 05 90 95

C\U

\E

1 ,

5

60 .

1

65 .

0

69.9 74.0 79.7 84 .

6

89 .

5

94.4

2.0 59.7 64 .

6

69 .

4

74.3 79 .

1

04 .

0

88.9 93.7

2.5 59.3 64 .

1

60.9 73.0 78.6 03.4 08.2 93.0

3.0 58.9 63.7 68.4 73.2 70.0 02.8 87.6 92 .

4

3.5 58 5 63.2 68.0 72.7 77.5 02.2 87 .

0

91.7

4 .

0

50 .

0

62.8 67.5 72.2 76.9 01 .

6

86.4 91 .

1

A . 5 57.6 62.3 67 .

0

71 .

7

76.4 81 .

1

85 .

8

90.5

5.0 57.2 61 .9 66 .

6

71 .2 75.9 00 .

5

85.2 89.0

5 .

5

56.9 61 .

5

66.1 70 .

7

75.3 00 .

0

84 .

6

89.2

6 .

0

56.5 61 .

1

65.7 70.2 74.0 79.4 04.0 88 .

6

6.5 56 .

1

60 .

6

65.2 69.8 74.3 78.9 83.5 88.0

7 0 55 .

7

60.2 64.8 69.3 73.0 78.4 82.9 87.4

7 .

5

55.3 59.8 64.3 68.0 73.3 77.8 82.3 86.8

0.0 55 .

0

59.4 63.9 68.4 72.9 77.3 81.8 06.3

8 .

5

54.6 59 .

1

63.5 67.9 72.4 76.8 81 .

3

85.7

9 .

0

54.3 58.7 63.1 67.5 71.9 76.3 80.7 85.1

\A ! R\F ! C\U ! \E1

60

DOE ENERGY FACTOR

65 70 75 80 85 90 95

ALL ; 59.1 64.1 69.0 73.9 78.0 03.8 08.7 93.6

Figure 7. Input Power 800 Watts, Burner Input 50,000 Btu/h

SEASONAL ENERGY UTILIZATION FACTOR

\A

R\F

C\U

\E

60 65 70 75 80 85 90 95

1 .

5

60.5 65.1 69.7 74.4 79.0 83.6 88 .

2

92.9

2.0 59.0 63.5 68.0 72.5 77 .

0

81 .

6

86.1 90.6

2.5 57.6 62.0 66.4 70.8 75.2 79.6 84.0 88.4

3.0 56.2 60 .

5

64.8 69.1 73.4 77.7 82.0 86.3

3.5. 55.0 59.2 63.4 67.6 71.7 75.9 80 .

1

84.3

4 .

0

53.7 57.0 61.9 66.0 70 .

1

74.2 78.3 82.5

4.5 52.5 56.6 60 .

6

64.6 68.6 72.6 76.6 80.6

5 .

0

51.4 55.3 59.3 63.2 67.1 71 .

1

75 .

0

78.9

5 .

5

50.3 54.2 58.0 61.9 65 .

7

69.6 73.4 77.3

6.0 49.3 53.1 56.8 60 .

6

64.4 68.1 71.9 75.7

6 .

5

48.3 52.0 55.7 59.4 63.1 66.8 70 .

5

74.1

7 .

0

47 .

4

51 .

0

54.6 50.2 61 .8 65 .

4

69 .

1

72.7

7.5 46.4 50.0 53.5 57.1 60 .

6

64.2 67.7 71.3

8 .

0

45 .

6

49 .

0

52.5 56 .

0

59.5 63.0 66.4 69 .

9

8.5 44.7 48.1 51 .

5

55 .

0

58.4 61.8 65.2 68.6

9.0

\A

43.9 47.2 50.6 53.9 57.3

DOE ENERGY FACTOR

60.7 64.0 67.4

R\F

C\U

\E

60 65 70 75 80 85 90 95

ALL i 56.9 61.6 66.4 71.1 75.9 00.6 85 3 90.1

22
Figure 8 . Input Power 800 Watts , Burner Input 100 , 000 Btu/h

5EA50NAL ENERGY UTILIZATION FACTOR

\A 1 R\F 60 65 70 75 80 85 90

C\U

\E

1.5 60.3 65 .

1

69.9 74.7 79.5 04.3 89.1

2.0 59.5 64.2 69.0 73.7 78.4 83.2 87.9

2.5 58.7 63.4 60.1 72.0 77.4 82.1 86.8

3.0 58.0 62.6 67.2 71.8 76.5 81 .

1

85 .

7

3.5 57.3 61.8 66.4 71 .

0

75.5 00 .

1

84.6

4.0 56.6 61 .

1

65.6 70 .

1

74.6 79.1 83 .

6

4.5 55.9 60.3 64.8 69.2 73.7 78.1 82.6

5 .

0

55.2 59 .

6

64.0 68.4 72.8 77.2 81 .

6

5.5 54.5 58.9 63.2 67.6 71.9 76.3 80 .

6

6 .

0

53.9 58.2 62.5 66.8 71 .

1

75.4 79.7

6.5 53.3 57.5 61 .

8

66 .

0

70.3 74.5 78.8

7.0 52.7 56.9 61 .

1

65.3 69 .

5

73.7 77.9

7.5 52.1 56.2 60 ,

4

64.5 68.7 72.8 77.0

8.0 51 .5 55 .

6

59.7 63.8 67.9 72.0 76.1

0.5 50.9 55 .

0

59.0 63.1 67.1 71.2 75.3

9.0 50.4 54.4 58.4 62.4 66.4 70 .

4

74.4

DOE ENERGY TACTOR

\A

R\F 60 65 70 75 00 85 90

C\U ! \E1

ALL 1 58.4 63.3 68.1 73.0 77.9 82.7 87.6

Figure 9. Input Power 800 Watts, Burner Input 150,000 Btu/h

3EAG0NAL ENERGY UTILIZATION FACTOR

\A ! R\F 60 65 70 75 80 85 90

C\U

\E

1.5 60 . 2 65. 0 69. 9 74. 0 79. 6 84 .5 89. 4

2.0 59. 6 64. 5 69. 3 74. 1 78. 9 83 .8 88. 6

2.5 59. 1 63. 9 68. 7 73. 5 78. 3 03 .0 87. 8

3.0 58. 6 63. 4 68. 1 72. 8 77. 6 82 .3 87. 1 3.5 • 50. 1 62. 8 67. 5 72. 2 76. 9 01 .6 86. 3

4 .

0

57. 6 62. 3 66. 9 71 . 6 76. 3 00 .9 85 . 6

4.5 57. 1 61 . 8 66 . 4 71 . 0 75. 6 80 .2 84. 9

5 .

0

56. 7 61 . 2 65 . 8 70. 4 75. 0 79 . 6 84. 2

5.5 56. 2 60 . 7 65 . 3 69. 8 74. 4 78 .9 83. 5

6.0 55. 7 60 . 2 64 . 7 69. 3 73 . 8 78 .3 82. 8

6.5 55. 3 59. 8 64. 2 68. 7 73. 2 77 6 82. 1 7.0 54. 8 59 . 3 63. 7 68. 1 72. 6 77 0 81 . 4

7.5 54. 4 58. 8 63. 2 67. 6 72. 0 76 .4 80 . 8

8.0 54. 0 58. 3 62. 7 67. 1 71

.

4 75 .8 80 . 1 8.5 53. 5 57. 9 62. 2 66

.

5 70 . 9 75 .2 79. 5

9 .

0

53. 1 57. 4 61 . 7 66. 0 70 . 3 74 . 6 78. 9

DOE ENERGY FACTOR

\A ! R\F ! 60 65 70 75 80 85 90

C\U ! \Ei

ALL ! 58.9 63.8 68.7 73.7 78.6 83.5 88.4

95

93.9

92.7

91.5

90.3

89.2

88.1

87.0

86.0

85.0

84.0

83.0

82.0

81 .

1

80.2

79.3

78.5

95

92.5

95

94.2

93.4

92.6

91.8

91.0

90.2

89.5

88.7

88.0

87.3

86.6

85.9

85.2

84.5

83.0

83.2

95

93.3

23
Seasonal Energy Utilization Factors ( SEUF) and DOE Energy

Factors vs. Furnace Power Rating (WAt.ts -EE) for Annual

Fuel Utilization Efficiencies (AFUE) from 60 to 95% and

for Electric to Fuel Cost Ratios (RC) from 1.5 to 8.5

Figure 10. Burner Fuel Input Rating 50,000 Btu/h

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 1.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\F

E\U

\E

60 65 70 75 80 85 90 95

300 . 60.2 65.0 69.9 74.8 79.6 84.5 89.3 94.2

400 . 60.3 65.1 69.9 74.7 79.5 84.3 89.1 93.9

500 . 60.3 65 .

1

69.8 74.6 79.4 84.1 88.9 93.6

600 . 60 .

4

65.1 69.8 74.5 79.2 83.9 88.6 93.4

700 . 60.4 65 .

1

69.8 74 .

4

79.1 83.8 88 4 93.1

000 . 60.5 65 .

1

69.7 74.4 79 .

0

83.6 88.2 92.9

DOE ENERGY FACTOR

\A

E\F 60 65 70 75 80 85 90 95

E\U

\E

300 . 58.0 63.7 68.6 73.5 78.4 03.3 88.2 93.1

400 . 58.4 63.3 68.1 73.0 77.9 82.7 87.6 92.5

500 . 58.0 62.9 67.7 72.5 77.4 02.2 87.0 91 .9

600 . 57.6 62.4 67.2 72.0 76.9 81.7 86.5 91.3

700 . 57.3 62.0 66.8 71 .

6

76.4 81 .

1

85 9 90.7

000 . 56.9 61 .

6

66.4 71 .

1

75.9 80 .

6

85.3 90.

1

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 2.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\F ! 60 65 70 75 80 85 90 95

E\U 1 \E!

300 . •! 59.0 63.8 68 .

5

73.3 78.

1

82.8 87 .

6

92.3

400 . 1 58 .

7

63.4 68.1 72.8 77.4 82.1 86.8 91.5

500 . ! 58.4 63.0 67.6 72.2 76.9 81 .

5

86.1 90.7

600 . ! 58 .

1

62.7 67.2 71.7 76 .

3

80.8 85 .

4

89.9

700 ! 57.9 62.3 66.8 71.3 75.7 00.2 84.7 89.1

800 . ! 57.6 62.0 66.4 70.8 75.2 79.6 84.0 88.4

DOE ENERGY FACTOR

\A

E\F ! 60 65 70 75 80 85 90 95

E\U ! \E ! 300 . ; 58.8 63.7 68 .

6

73.5 78.4 03.3 88.2 93 .

1

400 . { 58.4 63.3 68.

1

73.0 77.9 82.7 87.6 92 .

5

500 . 1 58.0 62.9 67.7 72.5 77.4 02.2 87 ,

0

91 .9 600 , ! 57.6 62 .

4

67.2 72.0 76.9 81.7 86.5 91.3

700 . ! 57.3 62.0 66.8 71.6 76.4 81 .

1

85.9 90.7

800 . ! 56.9 61 .

6

66.4 71 .

1

75.9 80 .

6

85.3 90.1

24
Figure 11. Burner Fuel Input Rate 50,000 Btu/h; RC - 3.5 4.5

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 3.5

SEASONAL ENERGY UTILIZATION FACTOR

\A 1 E\F 1 E\U 1 \E1

60 65

300 . 1 57.9 62.6

400 . \ 57.3 61.0

500 . ! 56.6 61 .

1

600 . 1 56.1 60.4

700 . 1 55.5 59.8

000 . ! 55.0 59.2

\A 1 E\F I 60 65

E\U ! \E I 300 . 58 8 63 7

400 . 58 4 63 3

500 . 58 0 62 9

600 . 57 6 62 4

700 . 57 3 62 0 800 . 56 9 61 6

70 75 00

67.2 71.9 76.6

66.4 71.0 75.5

65.6 70 .

0

74.5

64.8 69.2 73.6

64 .

1

68.3 72.6

63 .

4

67.6 71 .7

DOE ENERGY FACTOR

70 75 80

68.6 73.5 78.4

68.1 73.0 77.9

67.7 72.5 77.4

67.2 72.0 76.9

66.8 71.6 76.4

66.4 71 .

1

75.9

85 90 95

81.2 05.9 90.6

80.1 84.6 89.2

79.0 83.4 87.9

77.9 82.3 86.7

76.9 81.2 85.5

75.9 80 .

1

84.3

85 90 95

83.3 08.2 93.1

82.7 87.6 92.5

82.2 87.0 91.9

81.7 86.5 91.3

81.1 85.9 90.7

80.6 85.3 90.1

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC) = 4.5

SEASONAL ENERGY UTILIZATION FACTOR

\A ! E\F 60 65 70 75 80 85 90 95

E\U

\E

300 . 56.8 61.4 66.0 70.5 75.1 79.7 84.3 88.9

400 . 55.9 60.3 64.0 69.2 73.7 78.1 82.6 87.0

500 . 55.0 59.3 63.6 68.0 72.3 76.6 81.0 85.3

600 . 54.1 58.3 62.6 66.8 71.0 75.2 79.5 83.7

700 . 53.3 57.4 61.5 65.7 69.8 73.9 78.0 82.1

000 . 52.5 56.6 60 .

6

64.6 68 .

6

72.6 76 .

6

80 .

6

\A

E\F

E\U

\E

60 65

DOE

70

ENERGY

75

FACTOR

80 85 90 95

300 . 58.8 63 .

7

68.6 73.5 78.4 03.3 08.2 93 .

1

400 . 58.4 63.3 68 .

1

73.0 77.9 02.7 87.6 92.5

500 . 58.0 62.9 67.7 72.5 77.4 02.2 87.0 91 .9

600 . 57.6 62.4 67.2 72.0 76.9 81.7 86.5 91.3

700 . 57.3 62.0 66.8 71 .

6

76 .

4

81 .

1

85.9 90,7

800 . 56.9 61 .

6

66.4 71 .

1

75.9 00.6 85 .

3

90 .

1

25
Figure 12. Burner Fuel Input 50,000 Btu/h; RC - 5.5 and 6.5

ELECTRIC TO F05SIL FUEL BTU COST RATIO ( RC) = 5.5

SEASONAL ENERGY UTILIZATION FACTOR

\A 1 E\F

E\U

\E

60 65 70 75 80 85 90 95

300 . 55,8 60 .

3

64.0 69.0 73.7 78.0 80.7 87.0

400 . 54 .

5

58.9 63.0 67.6 71.9 76.3 80.6 85.0

500 . 53.4 57.6 61.8 66.0 70.0 74.4 78.6 80.9

600 . 50.3 56 .

4

60.5 64.6 68.6 70.7 76.8 80.9

700 . 51 .

3

55.3 59.0 63.0 67.1 71 .

1

75.1 79 .

0

000 . 50.3 54.0 58.0 61.9 65.7 69.6 73.4 77.3

\A

E\F

E\U

\E

60 65

DOE

70

ENERGY

75

FACTOR

80 85 90 95

300 . 58 .

8

63.7 68 .

6

73.5 78 .

4

83.3 08 .

0

93 .

1

400 . 58.4 63.3 68.1 73.0 77.9 80.7 87.6 90 .

5

500 . 58.0 60.9 67 .

7

70.5 77 4 80 .

0

87 .

0

91.9

600 . 57.6 60.4 67.0 70.0 76.9 81.7 06.5 91.3

700 . 57.3 60.0 66 .

0

71.6 76 4 01 .

1

85 .

9

90.7

000 . 56.9 61 .

6

66.4 71 .

1

75.9 80.6 05.3 90 .

1

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 6.5

SEASONAL ENERGY UTILIZATION FACTOR

\A ! E\F 60 65 70 75 80 85 90 95

E\U

\E

300 . 54.8 59.0 63.6 68.0 70.4 76.8 81 . 0 85.6

400 . 53.3 57.5 61.8 66.0 70.3 74.5 78. 8 83.0

500 . 51 .9 56.0 60 .

1

64.0 68.3 70.4 76. 5 80.5

600 . 50 .

6

54.6 58.5 60.5 66.4 70.4 74. 3 78.3

700 . 49 .

4

53.0 57.1 60.9 64.7 68.5 70. 3 76.1

000 . 48.3 50.0 55.7 59.4 63.1 66.8 70 . 5 74.1

\A

DOE ENERGY FACTOR

E\r

E\U

\E

60 65 70 75 00 85 90 95

300 . 58.8 63.7 68.6 73.5 78.4 03.3 88.0 93 .

1

400 . 58.4 63.3 68.1 73.0 77.9 80.7 87.6 90.5

500 . 58 .

0

60 .

9

67.7 70.5 77.4 80.0 87 .

0

91.9

600 . 57.6 60.4 67.0 70.0 76.9 81 .

7

86.5 91.3

700 . 57.3 60.0 66.8 71 .

6

76.4 81 .

1

85.9 90.7

800 . 56.9 61 .

6

66.4 71 .

1

75.9 00 .

6

05.3 90 1

26
Figure 13, Burner Fuel Input 50,000 Btu/h; RC = 7.5 and 8.5

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 7.5

SEASONAL ENERGY UTILIZATION FACTOR

\A 1 E\F 60 65 70 75 80 85 90 95

E\U

\E

300 . 53.8 58.

1

62.5 66.8 71 .

1

75.5 79.8 8A.

AOO . 52.1 56.2 60. A 6A.5 60.7 72.8 77.0 81 . 500 . 50 .

5

5A.5 50.5 62. A 66 . A 70. A 7A. A 78.

600 . A9.0 52.9 56.7 60.5 6A.3 68.2 72.0 75.

700 . A7.

7

51 . A 55 .

1

58.7 62. A 66.1 69.8 73.

000 . A6 . A 50 .

0

53.5 57.1 60 .

6

6A.2 67.7 71 .

DOE ENERGY FACTOR

\A

CNF 60 65 70 75 80 85 90 95

E\U

\E

300 . 58.8 63.7 60 .

6

73.5 78. A 83.3 88 .

2

93.

AOO . 58. A 63.3 68.1 73.0 77.9 82.7 87.6 92.

500 . 58.0 62.9 67.7 72.5 77. A 82.2 87.0 91 . 600 . 57.6 62. A 67 .

2

72.0 76.9 81.7 86.5 91 . 700 . 57.3 62.0 66.0 71 .

6

76. A 01 .

1

85.9 90 . 800 . 56.9 61 .

6

66. A 71 .

1

75.9 80 .

6

85.3 90 .

ELECTRIC TO FOSSIL FUEL BTU COST RATIO (RC)= 8.5

SEASONAL ENERGY UTILIZATION FACTOR

\A 1 E\F

E\U

\E

60 65 70 75 80 85 90 95

300 . 52.8 57.1 61 .A 65 .

6

69.9 7A. 1 78. A 82.

AOO . 50.9 55 .

0

59 .

0

63.1 67.1 71.2 75.3 79.

500 . A9 .2 53.0 56.9 60.8 6A.7 68.5 72. A 76.

600 . A7 .

5

51.3 55 .

0

58.7 62. A 66.1 69.8 73.

700 . A6.

1

A9.6 53.2 56.7 60.3 63.8 67. A 71 . 800 . AA.7 A8.

1

51 .5 55.0 58 . A 61.8 65.2 68.

\A 1 E\F I E\U 1 \E 1

60 65

DOE

70

ENERGY

75

FACTOR

80 85 90 95

300 . 1 58.8 63.7 68.6 73.5 78. A 83.3 88.2 93 . AOO . 1 58. A 63.3 68.1 73.0 77 .

9

82.7 87.6 92.

500 . ! 58.0 62 .

9

67.7 72.5 77. A 82.2 87.0 91 . 600 . ! 57 .

6

62. A 67.2 72.0 76 .

9

81.7 86 .

5

91 . 700 . ! 57.3 62.0 66.3 71 .6 76 . A 81 .

1

35.9 90 . 800 . ! 56.9 61 .

6

66. A 71 .

1

75.9 80 .

6

85 .

3

90 . STOP

1

1A8

53

15

9

3

7

1

7

3

3

5

06

\

15

9

3

7

1

27
Figure 14 . Burner Input 100 , 000 Btu/hr ; RC - 1.5 and 2 .

5

ELECTRIC TO F055IL FUEL BTU COST RATIO ( RC ) = 1.5

SEASONAL ENERGY UTILIZATION FACTOR

\A 1 E\F 1 60 65 70 75 80 05 90 95

E\U 1 \E!

300 . ! 60 1 65.0 69.9 74.9 79.3 04.7 09.6 94.6

AOO . : 60 .

1

65.0 69.9 74.0 79.7 84.6 89 5 94.4

500 . I 60 .

2

65 .

0

69.9 74.8 79 .

7

04.5 89 .

4

94.3

600 . ! 60.2 65.0 69.9 74.0 79 .

6

84.5 89.3 94.2

700 1 60 .

2

65 .

1

69 .

9

74 .

7

79.5 04.4 89.2 94.0

000 . i 60.3 65 .

1

69.9 74.7 79 .

5

04.3 09.

1

93 .

9

\A 1 E\F 1 E\U ! \E I

60 65

DOE

70

ENERGY

75

FACTOR

00 85 90 95

300 . ! 59.4 64 .

3

69.3 74.2 79.2 84.1 89.1 94.0

400 . ! 59.2 64.1 69 .

1

74.0 70.9 03.9 88.8 93.7

500 . ! 59 .

0

63.9 68.8 73.7 78.7 03.6 88.5 93.4

600 . i 58 .

0

63.7 68 .

6

73.5 78.4 83.3 88.2 93.1

700 . ! 50.6 63.5 68.4 73.2 78.1 03 .

0

87.9 92.8

000 . 1 58.4 63.3 68.1 73.0 77.9 82.7 87.6 92.5

ELECTRIC TO FOSSIL FUEL DTU COST RATIO ( RC) = 2.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\F ! E\U ! \E!

60 65 70 75 80 05 90 95

300 . ! 59.5 64.4 69.3 74.1 79.0 03.9 88.8 93.6

400 . 1 59.3 64.2 69.0 73.0 70.7 03.5 88.3 93.2

500 . ! 59.2 64.0 68.8 73 .

6

78.4 03.2 08.0 92.7

600 . 1 59.0 63.8 68.5 73.3 70.1 82.8 87 .

6

92.3

700 . ! 58.9 63.6 63.3 73.0 77.7 02.5 87.2 91.9

000 . ! 58.7 63.4 68.1 72.0 77.4 02.1 86.8 91.5

DOE ENERGY FACTOR

\A ! E\F ! 60 65 70 75 80 85 90 95

E\U 1 \EI

300 . ! 59.4 64.3 69.3 74.2 79.2 04.1 89.1 94.0

400 . 1 59.2 64.1 69.1 74.0 70.9 83.9 88.8 93.7

500 . ! 59.0 63.9 60.8 73.7 70.7 03.6 08.5 93.4

600 . ! 58.8 63.7 68.6 73.5 78.4 83.3 88.2 93.1

700 . ! 58.6 63.5 68.4 73.2 78.1 03.0 87.9 92.8

800 . I 58.4 63.3 68.1 73.0 77.9 82.7 87.6 92.5

28
Figure 15. Burner Input 100,000 Btu/hr; RC - 3.5 and 4.5

ELECTRIC TO F055IL FUEL BTU COST RATIO ( RC ) = 3.5

SEASONAL ENERGY UTILIZATION FACTOR

\A ! E\F ! 60 65 70 75 80 85 90 95

E\U ! \E!

300.! 58.9

400 . ! 58.6

500 .1 58.2

600 .1 57.9

700 . ! 57.6

800 .1 57.3

\A ! E\F ! 60

E\U ! \E!

300 . 59.4 64.3 69.3 74.2 79.2 84.1 89.1 94.0

400 . 59.2 64.1 69.1 74.0 78.9 83.9 88.8 93.7

500 . 59.0 63.9 68.8 73.7 78.7 83.6 88.5 93.4

600 . 58.8 63.7 68.

6

73.5 78.4 83.3 88.2 93.1

700 . 50.6 63.5 68.4 73.2 73.1 S3.0 87.9 92.8

800 . 58.4 63.3 68.1 73.0 77.9 82.7 87.6 92.5

63.7

63.3

62.9

62.6

62.2

61.8

65

68.6

68.1

67.7

67.2

66.8

66.4

73.4

72.9

72.4

71.9

71.4

71.0

78.2

77.7

77.1

76.6

76.0

75.5

83.0

82.4

81.8

81.2

80 .

6

80.1

87.9

87.2

86.5

85.9

85.3

84.6

90

92.7

92.0

91.3

90 .

6

89.9

89.2

95

DOE ENERGY FACTOR

70 75 80 85

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 4.5

SEASONAL ENERGY UTILIZATION FACTOR

\A ! E\F

E\U

\E

60 65 70 75 80 85 90 95

300 . 58.3 63.1 67.9 72.7 77.5 82.2 87.0 91.0

400 . 57.8 62.5 67.2 71.9 76.7 81.4 86.1 90.8

500 . 57.3 61.9 66 .

6

71.2 75.9 80.5 85.2 89.8

600 . 56.8 61.4 66.0 70.5 75.1 79.7 84.3 88.9

700 . 56.3 60.8 65.4 69.9 74.4 78.9 83.4 87.9

800 . 55.9 60.3 64.8 69.2 73.7 78.1 82.6 07.0

\A ! E\F I E\U ! \E1

60 65

DOE

70

ENERGY

75

FACTOR

80 85 90 95

300 . I 59.4 64.3 69.3 74.2 79.2 04.1 89.1 94 .

0

400 . ! 59.2 64.1 69.

1

74.0 78.9 83.9 88.8 93 .

7

500 . 1 59.0 63.9 68 .

8

73.7 78 .

7

03.6 88.5 93.4

600 . 1 58.8 63 .

7

68.6 73.5 70.4 83.3 88.2 93.1

700 . ! 58.6 63.5 68.4 73.2 78.1 03.0 87.9 92.8

800 .

1

58.4 63.3 68.1 73.0 77.9 82.7 87 .

6

92.5

29
Figure 16 . Burner Input 100 , 000 Btu/hr ; RC — 5.5 and 6 .

5

ELECTRIC TO F0G5IL FUEL BTU COST RATIO ( RC ) = 5.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\F

E\U

\E

60 65 70 75 80 05

300 . AOO . 500 . 600 . 700 . 800 .

57.8

57 .

1

56 . A 55.0

55.1

5A.5

62.5

61.7

61 .

0

60.3

59.6

58.9

67.2

66. A

65.6

6A.0

6A. 0

63.2

72.0

71.0

70 .

1

69.2

68. A 67.6

76.7

75.7

7A.7

73.7

72.8

71.9

81 .A 80.3

79.3

78.2

77.2

76.3

90

86.2

85.0

83.8

82.7

81.7

80.6

DOE ENERGY FACTOR

\A 1 E\F 1 60 65 70 75 80

E\U 1 \E!

300 . 1 AOO . 1 500. 1 600 .

:

700 . 1 000 . !

59. A

59.2

59.0

58.8

58 .

6

50. A

6A.3

6A. 1 63.9

63.7

63.5

63.3

69.3

69.1

68.0

68.6

68. A

68.1

7A.2

7A. 0

73.7

73.5

73.2

73.0

79.2

70.9

78.7

70. A

78.1

77.9

85 90

QA.l 89.1

03.9 88.8

03.6 88.5

03.3 88.2

83.0 87.9

82.7 87.6

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 6.5

\A 1 E\F ! E\U 1 \E!

300. I AOO . 1 500 . ! 600 . ! 700 . ! 800 . !

SEASONAL ENERGY UTILIZATION FACTOR

65 70 75 80 05

57.2 61.9

56.-^ 61.0

55.5 60.0

5A.8 59.2

5A-0 58.3

53.3 57.5

66.6 71.3

65.5 70.1

6A.5 69.0

63.6 68.0

62.7 67.0

61.0 66.0

76.0

7 A.

7

73.5

72. A

71.3

70.3

80.7

79.3

78.0

76.8

75.6

7A.5

85.3

83.9

82.5

81.2

80.0

78.8

\A

E\F I E\U ! \E!

60

300 . ! 59. A

AOO . 1 59.2

500 . ! 59.0

600 . 1 58.0

700 . 1 58.6

800 . 1 58. A

DOE

65 70

6A.3 69.3

6A. 1 69.1

63.9 68.0

63.7 68.6

63.5 68 . A

63.3 68.1

ENERGY FACTOR

75 80

7A.2 79.2

7A.0 78.9

73.7 78.7

73.5 70 .

A

73.2 70.1

73.0 77.9

85 90

8A. 1 89.1

83.9 88.8

83.6 88.5

03.3 08.2

03.0 87 9

82.7 07.6

95

90.9

89.6

08. A 87.2

86.1

85.0

95

9A.0

93.7

93. A 93.1

92.8

92.5

95

90.0

88.5

87.1

85.6

8A.3

83.0

95

9A.0

93.7

93. A 93.1

92.8

92.5

30
Figure 17. Burner Input 100,000 Btu/hr; RC - 7.5 and 8.5

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 7.5

SEASONAL ENERGY UTILIZATION FACTOR

\A ! E\F 60 65 70 75 80 85 90 95

E\U

\E

300 . 56.7 61.3 66.0 70.6 75.0 79.9 84.5 89.2

400 . 55.7 60.2 64.7 69.3 73.8 70.3 82.9 87.4

500 . 54.7 59.1 63 .

6

68.0 72.4 76.9 81.3 85.7

600 . 53.8 58.1 62.5 66.0 71 .

1

75.5 79.8 84.1

700 . 52.9 57.1 61.4 65.6 69.9 74.1 78.4 82.6

OOO . 50.1 56.0 60.4 64.5 68.7 72.8 77.0 81 .

1

\A

E\F 60 65

DOE

70

ENERGY

75

FACTOR

80 85 90 95

E\U

\E

300 . 59.4 64.3 69.3 74.2 79.2 84.1 89.1 94.0

400 . 59.2 64.1 69.1 74.0 78.9 83.9 88.8 93.7

500 . 59.0 63.9 68.8 73.7 78.7 03.6 88.5 93.4

600 . 58.8 63.7 68.6 73.5 78.4 83.3 08.2 93.1

700 . 58.6 63.5 68.4 73.2 78.1 33.0 07.9 92.8

000 . 58.4 63.3 68.1 73.0 77.9 82.7 87.6 92.5

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 8.5

SEASONAL ENERGY UTILIZATION FACTOR

\A ! E\F ! 60 65 70 75 00 85 90 95

E\U 1 \E1

300 . ! 56.1 60.7 65.3 69.9 74.5 79.1 83.7 88.3

400. I 55.0 59.5 63.9 68.4 72.9 77.4 81.9 86.3

500 . ! 53.9 58.3 62.6 67.0 71 .

4

75.7 80.1 84.5

600 . i 52.8 57.1 61.4 65.6 69.9 74.1 78.4 82.7

700 . ! 51.9 56.0 60.2 64.3 68.5 72.6 76.8 81.0

800 . ! 50.9 55.0 59.0 63.1 67.1 71.2 75.3 79.3

\ A DOE ENERGY FACTOR

C\F 60 65 70 75 00 05 90 95

E\U

\E

300 . 59.4 64.3 69.3 74.2 79.2 84.1 09.1 94.0

400 . 59.2 64.1 69.1 74.0 78.9 83.9 88.8 93.7

500 . 59.0 63.9 68.8 73.7 78.7 83.6 88.5 93.4

600 . 58.8 63.7 68.6 73.5 78.4 83.3 88.2 93.1

700 . 58.6 63.5 68.4 73.2 78.1 03.0 87.9 92.8

000 . 58.4 63.3 68.1 73.0 77.9 02.7 87.6 92.5

STOP

31
Figure 18 . Burner Input 150 , 000 But/hr ; RC - 1 . 5 and 2 .

5

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 1.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\F 1 60 65

E\U ! \E 1 300 . 1 60 .

1

65.0

AOO . ! 60 .

1

65.0

500 . ! 60 .

1

65.0

600 . ! 60 .

1

65.0

700 . 1 60.2 65.0

800 . ! 60.2 65.0

70 75 80

70 , 0 7A. 9 79. 9

70 0 7A. 9 79,.8

69 9 7A..9 79 .8

69 .9 7 A .8 79 ,7

69 .9 7A .3 79 .7

69 .9 7A .0 79 . 6

85 90 95

84.8 89.8 94.7

84.8 89.7 94.6

84.7 89.6 94.5

84.6 89.5 94.4

84.6 89.5 94.3

84.5 89.4 94.0

\A 1 E\F i E\U ! \E1

60 65

300 . 1 59 .

6

64.

400 . ! 59.5 64.

500 . ! 59.3 64.

600 . ! 59.2 64.

700 . 1 59 .

1

64.

800 . I 58.9 63.

DOE ENERGY FACTOR

70 75 80

69.5 74.5 79.5

69.4 74.3 79.3

69.2 74.2 79.1

69.1 74.0 78.9

68.9 73.8 78.7

68.7 73.7 78.6

85 90 95

84.4 89.4 94.4

84.2 89.2 94.1

84 .

0

89.0 93.9

83.9 88.8 93.7

83.7 88.6 93.5

83.5 88.4 93.3

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 2.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\F i 60 65

E\U 1 \EI

300 . ! 59.7 64. 6

400 . ;

• 59.6 64. 4

500 . ! 59.4 64. 3

600 . ! 59.3 64. 2

700 . 1 59.2 64. 0

800 .

1

59 .

1

63. 9

\A

E\F ! 60 65

E\U 1 \E1

300 . 1 59.6 64.6

400 .

;

59.5 64.4

500 . ! 59.3 64.3

600 . 1 59.2 64.1

700 . ! 59.1 64.0

GOO . 1 58.9 63.8

70 75 80

69.5 74.4 79.3

69.3 74.2 79.1

69.2 74.0 78.9

69.0 73.8 78.7

68.9 73.7 78.5

68.7 73.5 78.3

DOE ENERGY FACTOR

70 75 80

69.5 74.5 79.5

69.4 74.3 79.3

69.2 74.2 79.1

69.1 74.0 78.9

68.9 73.8 78.7

68.7 73.7 78.6

85 90 95

84.2 89.2 94.1

84.0 88.9 93.8

83.8 08.6 93.5

83.5 88.3 93.2

83.3 88.1 92.9

83.0 87.0 92.6

85 90 95

84.4 89.4 94.4

84.2 89.2 94.1

84.0 89.0 93.9

83.9 88.8 93.7

83.7 88.6 93.5

83.5 88.4 93.3

32
Figure 19. Burner Input 150,000 Btu/hr; RC - 3.5 and 4.5

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 3.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\F ! E\U 1 \e:

60 65 70

300 . ! 59.3 64.1 69.0

400 . 1 59 .

0

63.9 68.7

500 . I 58.8 63.6 68.4

600 . i 58.6 63.3 68.1

700 . ! 58.3 63.1 67.8

OOO . 1 58.1 63.8 67.5

\A ! E\F ! E\U I \E!

60 65

DOE

70

300 . ! 59.6 64.6 69.5

400 . ! 59.5 64.4 69.4

500 . ! 59.3 64.3 69.3

600 . ! 59.2 64.1 69.1

700 . 1 59.1 64.0 68.9

800 . ! 58.9 63.8 68.7

75 80 85 90 95

73.9 78.8 83.7 88.6 93.4

73.6 78.4 83.3 88.1 92.9

73.2 78.0 83.8 87.6 92.5

73.9 77.7 83.4 87.2 92.0

72.5 77.3 83.0 86.8 91.5

72.2 76.9 81 .

6

86.3 91 .

0

ENERGY FACTOR

75 80 85 90 95

74.5 79.5 84.4 89.4 94.4

74.3 79.3 84.2 89.2 94.1

74.2 79.1 84.0 89.0 93.9

74.0 78.9 83.9 88.8 93.7

73.8 78.7 83.7 88.6 93.5

73.7 78.6 83.5 88.4 93.3

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = A.

5

SEASONAL ENERGY UTILIZATION FACTOR

\A 1 E\F 60 65 70 75 80 85 90 95

E\U

\E

300 . 58.9 63.7 68.6 73.4 78.3 83.1 88.0 92.8

400 . 58.5 63.3 68.1 72.9 77.7 82.5 87.3 92.1

500 . 58.2 62.9 67.7 72.4 77.2 81.9 86.7 91.5

600 . 57.8 62.5 67.2 71.9 76.7 81.4 86.1 90.8

700 . 57.5 62.1 66.8 71.5 76.1 80.8 85.5 90.1

800 . 57.1 61.8 66.4 71.0 75.6 80.2 84.9 89.5

DOE ENERGY FACTOR

\A

E\F 60 65 70 75 80 85 90 95

E\U

\E

300 . 59.6 64.6 69.5 74.5 79.5 34.4 89.4 94.4

400 . 59.5 64.4 69.4 74.3 79.3 84.2 89.2 94.

1

500 . 59.3 64.3 69.2 74.2 79 .

1

84.0 89.0 93.9

600 . 59.2 64.1 69.1 74.0 78.9 83.9 88.8 93.7

700 . 59.1 64.0 68 .

9

73.8 78.7 83.7 08.6 93.5

800 . 58.9 63.8 68.7 73.7 78 .

6

83.5 08 .

4

93.3

33
Figure 20. Burner Input 150,000 Btu/hr; RC - 5.5 and 6.5

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 5.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\F 60 65 70 75 80 85 90 95

E\U

\E

300 . 58.5 63.3 68.1 72.9 77.8 02.6 87.4 92.2

400 . 58.0 62.8 67.5 72.3 77.1 81.0 86.6 91.3

500 . 57.5 62.2 66.9 71.7 76.4 81 .

1

85.8 90.5

600 . 57.1 61.7 66.4 71 .

0

75.7 80.3 85.0 89.6

700 . 56 .

6

61.2 65.8 70.4 75.0 79.6 84.2 88.8

800 . 56.2 60.7 65.3 69.8 74.4 78.9 83.5 88.0

DOE ENERGY FACTOR

\A

E\F 60 65 70 75 80 05 90 95

E\U

\E

300 . 59.6 64.6

400 . 59.5 64.4

500 . 59.3 64.3

600 . 59.2 64.1

700 . 59.1 64.0

800. 58.9 63.8

69.5 74.5 79.5

69.4 74.3 79.3

69.2 74.2 79.1

69.1 74.0 78.9

68.9 73.8 78.7

68.7 73.7 78.6

04.4 89.4 94.4

84.2 89.2 94.1

04.0 89.0 93.9

83.9 80.8 93.7

03.7 88.6 93.5

83.5 08.4 93.3

ELECTRIC TO FOSSIL FUEL BTU COST RATIO (RC)= 6.5

SEASONAL ENERGY UTILIZATION FACTOR

\A

E\r 60 65 70 75 80 85 90 95

E\U

\E

300 . 50.1 62.9 67.7 72.5 77.3 82.0 86.8 91.6

400 . 57.5 62.2 66.9 71.7 76.4 81 .

1

05.8 90.6

500 . 56.9 61.6 66.2 70.9 75.6 80.2 84.9 89.5

600 . 56.4 61.0 65.5 70.1 74.7 79.3 83.9 88.5

700 . 55.8 60.3 64.9 69.4 73.9 78.5 03.0 87.5

800 . 55.3 59.8 64.2 68.7 73.2 77.6 02 .

1

86.6

\A 1 DOE ENERGY FACTOR

E\F ! E\U ! \E160 65 70 75 80 85 90 95

300 . ! 59.6 64.6 69.5 74.5 79.5 84.4 09.4 94.4

400 . 1 59.5 64.4 69.4 74.3 79.3 84.2 89.2 94.1

500 . ! 59.3 64.3 69.2 74.2 79.1 04.0 89.0 93.9

600 . 1 59.2 64.1 69.1 74.0 78.9 03.9 88.8 93 .

7

700 . ! 59.1 64.0 68.9 73.8 70.7 03.7 88.6 93.5

800 . 1 58.9 63.0 60.7 73.7 78.6 83.5 88.4 93 .

3

34
Figure 21. Burner Input 150,000 Btu/hr; RC - 7.5 and 8.5

ELECTRIC TO FOSSIL FUEL DTU COST RATIO ( RC ) = 7.5

SEASONAL ENERGY UTILIZATION FACTOR

\A ! E\r

E\U

\E

60 65 70 75 80 05 90 95

300 . 57 .

7

62.5 67.2 72.0 76.0 01.5 86.3 91 .

0

^-iOO , 57 .

0

61 .

7

66.4 71 .

1

75.7 80 .

4

85.

1

09.0

500 . 56 .

3

60.9 65 .

5

70.2 74.8 79.4 04.0 88.6

600 . 55.7 60.0 64.7 69.3 73.0 78.3 82.9 07.4

700 . 55 .

0

59.5 64.0 68.4 72.9 77.4 81.8 86.3

000 . 54. A 50.8 63.2 67.6 72.0 76.4 80.8 85.2

\A ! E\r ! E\U 1 \E!

60 65

DOE

70

ENERGY

75

FACTOR

80 85 90 95

300 . ! 59.6 64.6 69.5 74.5 79.5 04.4 89.4 94.4

400 . I 59.5 64.4 69.4 74.3 79.3 04.2 89.2 94.1

500 . ! 59.3 64.3 69.2 74.2 79.

1

84.0 09.0 93.9

600 . I 59.2 64.1 69.1 74.0 70 .

9

83.9 88.0 93.7

700 . I 59.1 64.0 68.9 73.8 70 .

7

03.7 88.6 93.5

000 . 1 58.9 63.8 68.7 73.7 78.6 83.5 08.4 93.3

ELECTRIC TO FOSSIL FUEL BTU COST RATIO ( RC ) = 0.5

SEASONAL ENERGY UTILIZATION FACTOR

\A ! E\r I 60 65 70 75 80 05 90 95

E\U ! \E!

300 . 57.4 62.1

400 . 56.5 61.2

500 . 55.7 60.3

600 . 55.0 59.5

700 . 54.2 58.7

000 . 53.5 57.9

\A ! E\F i E\U ! \E!

60 65

300 . ! 59.6 64.6

400 . ! 59.5 64.4

500 . ! 59.3 64.3

600 . ! 59.2 64.1

700 . 1 59.1 64.0

800 . ! 58.9 63.0

STOP

66.8 71.5 76.3

65.8 70.5 75.1

64.9 69.4 74 .

0

63.9 68.4 72.9

63.1 67.5 71.9

62.2 66.5 70.9

DOE ENERGY FACTOR

70 75 00

69.5 74.5 79.5

69.4 74.3 79.3

69.2 74.2 79.1

69.1 74.0 78.9

60.9 73.0 70.7

68.7 73.7 78.6

81.0 05.7 90.4

79.7 84.4 89.0

78.5 83.1 87.7

77.4 81.9 86.3

76.3 80.7 85.1

75.2 79.5 83.8

85 90 95

34.4 89.4 94.4

84.2 89.2 94.1

84.0 39 .

0

93.9

03.9 00.8 93.7

83.7 38 .

6

93.5

83.5 08.4 93.3

35
U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 87-3645

2. Performing Organ. Report No. 3. Publication Date OCTOBER 1987

4. TITLE AND SUBTITLE

A Study of Three Measures for Energy Efficiency of Fossil Fueled Furnaces and Boilers

5. AUTHOR(S)

Esher Kweller

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

NATIONAL BUREAU OF STANDARDS

U.S. DEPARTMENT OF COMMERCE

GAITHERSBURG, MD 20899

7. Contract/Grant No.

t. Type of Report & Period Covered

NBSIR

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State, ZIP)

U.S. Department of Energy

Office of Builidng Energy Research and Development

Washington, DC 20585

10.

SUPPLEMENTARY NOTES

I I Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here)

The effectiveness of three measures of energy efficiency for furnaces has been

demonstrated by comparison of the results for predicted energy savings against the

cost savings predicted by the calculated total annual cost of operation using DOE

test procedures. Two of the efficiency measures currently prescribed by DOE - the

Annual Fuel Utilization Efficiency (AFUE) and the DOE Energy Factor (EF) are compared

with an industry proposed energy factor - Seasonal Energy Utilization Factor (SEUF)

.

Various parameters which affect the SEUF fattor'have also been demonstrated. These

include the effects of power rating (wattage), burner input rating, electric to fossil

fuel cost ratio, and the effect of annual fuel utilization efficiency (AFUE).

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

annual efficiency, boilers, combustion equipment, efficiency, furnaces, operating

costs

13. AVAILABILITY

niimited

I I For Official Distribution, Do Not Release to NTIS

I I Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

43

15. Price

$11.95

USCOMM'DC e043>PS0