9-B-i

APPENDIX 9-B. CENTRAL AIR CONDITIONER, HEAT PUMP, AND FURNACE

EQUIPMENT SWITCHING ANALYSIS

TABLE OF CONTENTS

9-B.1 INTRODUCTION ................................................................................................. 9-B-1

9-B.2 EQUIPMENT SWITCHING BETWEEN SPLIT SYSTEM HEAT PUMPS 

AND CENTRAL AIR CONDITIONERS WITH ELECTRIC FURNACES ....... 9-B-1

9-B.2.1 Methodology Overview ......................................................................................... 9-B-1

9-B.2.2 Determination of Payback Period for the Household Sample ............................... 9-B-2

9-B.2.2.1 Total Installed Cost Differential .......................................................... 9-B-3

9-B.2.2.2 Calculation of Operating Cost Savings................................................ 9-B-6

9-B.2.3 Determination of Payback Criteria for Equipment Switching............................... 9-B-6

9-B.2.4 Calculation of Cooling and Heating Load Fractions ............................................. 9-B-7

9-B.2.5 Treatment of Dual Fuel/Hybrid Systems............................................................... 9-B-7

9-B.2.6 Summary of Results............................................................................................... 9-B-8

9-B.2.6.1 Estimated Percent Switching ............................................................... 9-B-8

9-B.2.6.2 Cooling Load Fraction ......................................................................... 9-B-9

9-B.2.6.3 Heating Load Fraction ....................................................................... 9-B-11

9-B.3 EQUIPMENT SWITCHING BETWEEN GAS FURNACES AND 

ELECTRIC SPACE HEATING .......................................................................... 9-B-13

9-B.3.1 Heating Energy Use Criteria................................................................................ 9-B-13

9-B.3.2 Installation Costs.................................................................................................. 9-B-15

9-B.3.3 Conclusions.......................................................................................................... 9-B-17

LIST OF TABLES

Table 9-B.2.1 Total Installed Cost for Split System Heat Pump ...................................... 9-B-3

Table 9-B.2.2 Total Installed Cost for Split System A/C (Coil-Only) ............................. 9-B-3

Table 9-B.2.3 Total Installed Cost of Electric Furnace for Split System A/C (CoilOnly) .......................................................................................................... 9-B-4

Table 9-B.2.4 Total Installation Cost Differential, South Hot-Humid (2009$)................ 9-B-4

Table 9-B.2.5 Total Installation Cost Differential, South Hot-Dry (2009$)..................... 9-B-5

Table 9-B.2.6 Total Installation Cost Differential, North (2009$)................................... 9-B-5

Table 9-B.2.7 Total Installation Cost Differential, National (2009$)............................... 9-B-5

Table 9-B.2.8 Average UEC for Split System Heat Pumps at the Baseline Efficiency 

Level (13 SEER) by Region ...................................................................... 9-B-7

Table 9-B.2.9 Fraction of Dual Fuel/Hybrid Systems...................................................... 9-B-7

Table 9-B.2.10 Estimated Percent Switching from Split-System Heat Pump to SplitSystem Air-Conditioners and Electric Furnaces, South Hot-Humid......... 9-B-8

Table 9-B.2.11 Estimated Percent Switching from Split-System Heat Pump to SplitSystem Air-Conditioners and Electric Furnaces, South Hot-Dry.............. 9-B-8

Table 9-B.2.12 Estimated Percent Switching from Split-System Heat Pump to SplitSystem Air-Conditioners and Electric Furnaces, North ............................ 9-B-9
9-B-ii

Table 9-B.2.13 Estimated Percent Switching from Split-System Heat Pump to SplitSystem Air-Conditioners and Electric Furnaces, National........................ 9-B-9

Table 9-B.2.14 Cooling Load Fraction, South Hot-Humid .............................................. 9-B-10

Table 9-B.2.15 Cooling Load Fraction, South Hot-Dry ................................................... 9-B-10

Table 9-B.2.16 Cooling Load Fraction, North.................................................................. 9-B-10

Table 9-B.2.17 Cooling Load Fraction, National ............................................................. 9-B-11

Table 9-B.2.18 Heating Load Fraction, South Hot-Humid............................................... 9-B-11

Table 9-B.2.19 Heating Load Fraction, South Hot-Dry ................................................... 9-B-12

Table 9-B.2.20 Heating Load Fraction, North.................................................................. 9-B-12

Table 9-B.2.21 Heating Load Fraction, National.............................................................. 9-B-12

Table 9-B.3.1 Common Residential Electric Furnace (Single Phase) Sizes and Single 

Circuit Heater Amps, Compared to Equivalent Gas Furnace Shipments 

by Input Capacity..................................................................................... 9-B-16

Table 9-B.3.2 Installation Costs for Adding a 50 amp Electrical Outlet for Electric 

Furnace..................................................................................................... 9-B-16

Table 9-B.3.3 Installation Costs for Adding a 100 amp Electrical Outlet for Electric 

Furnace..................................................................................................... 9-B-16

LIST OF FIGURES

Figure 9-B.2.1 Equipment Switching Methodology Flowchart......................................... 9-B-2

Figure 9-B.3.1 Heating Energy Use—North Region ....................................................... 9-B-14

Figure 9-B.3.2 Heating Energy Use—South Region ....................................................... 9-B-15
9-B-1

APPENDIX 9-B. CENTRAL AIR CONDITIONER, HEAT PUMP, AND FURNACE

EQUIPMENT SWITCHING MODEL

9-B.1 INTRODUCTION

To the extent that revised energy conservation standards result in an increase in the price 

of a covered product compared to a competing product, some consumers may purchase the 

competing product. DOE’s analysis seeks to account for such “equipment switching.”

DOE primarily considered the equipment switching between split system heat pumps and 

central air conditioners with an electric furnace.. DOE also considered possible equipment

switching between gas furnaces and electric space heating.

9-B.2 EQUIPMENT SWITCHING BETWEEN SPLIT SYSTEM HEAT PUMPS 

AND CENTRAL AIR CONDITIONERS WITH ELECTRIC FURNACES

9-B.2.1 Methodology Overview

DOE conducted an analysis of the potential for equipment switching between a split 

system heat pump and the combination of a split system central air conditioner and electric 

furnace. To estimate the likelihood of equipment switching between these two systems, DOE 

utilized data from Decision Analysts,1 which identified for a representative sample of consumers 

their willingness to purchase more efficient space-conditioning systems. From these data RECS 

2005 billing data2

, DOE deduced the average length of the payback period (PBP) for a more 

efficient split system heat pump that the consumer will require before switching to a combination 

of a split system central air conditioner and electric furnace.

Figure 9-B.2.1 illustrates the methodology used to determine the fraction of households 

that would switch to a combination of a split system central air conditioner and electric furnace 

should a higher standard for a split system heat pump be adopted.
9-B-2

Figure 9-B.2.1 Equipment Switching Methodology Flowchart

DOE used life-cycle cost (LCC) results for the total installed cost and operating cost to 

determine the payback for a more efficient split system heat pump for each household. DOE 

compared the PBP of the more efficient split system heat pump to the expected PBP deduced 

from the Decision Analysts’ data (3.6 years). If the PBP of installing a more efficient split 

system heat pump exceeds 3.6 years, DOE forecasted that the consumer would switch to the 

combination of a split system air conditioner and an electric furnace. This comparison is done for 

every possible pairing of split system heat pump and split system air conditioner efficiencies.

9-B.2.2 Determination of Payback Period for the Household Sample

The PBP for the purposes of equipment switching is the amount of time it takes the 

customer to recover the assumed higher purchase cost of more energy efficient equipment as a 

result of lower operating costs. Numerically, the PBP is the ratio of the increase in purchase cost 

(i.e., from a less efficient design to a more efficient design) to the decrease in annual operating 

expenditures.

The equation for PBP is:

PBP =∆IC/∆OC

Where:

PBP = payback period in years,

∆ IC = difference in the total installed cost between split system heat pump and the 

combination of split system central air conditioner plus electric furnace (see 

section 9-B.2.2.1), and

∆OC = difference in annual operating costs (see section 9-B.2.2.2).

Total Installed

Cost Difference

Operating Cost

Difference

Payback

Calculation

Payback

> 3.6

years?

YES Switch

NO Don’t Switch

LCC Results

(Weighted Average

by Region)

LCC Results for

each household

Payback Criteria

based on Decision

Analyst Data
9-B-3

The sections below describe the determination of the total installed cost and operating 

cost differentials.

9-B.2.2.1 Total Installed Cost Differential

For the calculation of the equipment switching payback, DOE used the average total 

installed costs calculated in the air conditioner LCC spreadsheet by region as shown in Table 9-

B.2.1 and Table 9-B.2.2. 

Table 9-B.2.1 Total Installed Cost for Split System Heat Pump

Efficiency Level

SEER

National Average 

2009$

Hot-Humid Region

2009$

Hot-Dry Region

2009$

Rest of Country

2009$

13 3,226 2,909 3,945 3,173

13.5 3,297 2,977 4,033 3,241

14 3,368 3,045 4,120 3,309

14.5 3,444 3,117 4,213 3,381

15 3,518 3,189 4,305 3,453

15.5 3,591 3,259 4,394 3,523

16 3,698 3,361 4,523 3,626

16.5 3,776 3,436 4,617 3,701

17 3,853 3,510 4,711 3,776

18 4,015 3,666 4,905 3,934

19 4,142 3,784 5,074 4,050

20 4,233 3,867 5,196 4,138

21 4,374 3,998 5,383 4,265

22 4,433 4,047 5,462 4,328

Table 9-B.2.2 Total Installed Cost for Split System A/C (Coil-Only)

Efficiency Level

SEER

National Average 

2009$

Hot-Humid Region

2009$

Hot-Dry Region

2009$

Rest of Country

2009$

13 2,360 2,020 2,824 2,313

13.5 2,416 2,071 2,891 2,366

14 2,482 2,131 2,970 2,429

14.5 2,556 2,198 3,058 2,501

15 3,158 2,729 3,788 3,076

15.5 3,769 3,268 4,529 3,660

16 3,876 3,365 4,656 3,765

16.5 3,970 3,453 4,773 3,851

17 4,073 3,549 4,902 3,946

18 4,157 3,630 5,018 4,008

In order to calculate the additional total installed cost of adding an electric furnace to the 

split system air conditioner, DOE assumed that this additional cost was approximately equal to 

the difference between a split system heat pump and a split system air-conditioning (coil only) 

unit at the same efficiency level. Table 9-B.2.3 shows the electric furnace total installed cost by 
9-B-4

split system air conditioner (coil only) efficiency level. All values are within the average national 

value range of $715 for a 10.2 MMBtu/h and $900 for a 34.1 MMBtu/h calculated in RS Means 

Residential Cost Data, with the exception of the Hot-Dry Region which has much greater 

equipment markups.

Table 9-B.2.3 Total Installed Cost of Electric Furnace for Split System A/C (Coil-Only)

Efficiency Level

SEER

National Average 

2009$

Hot-Humid Region

2009$

Hot-Dry Region

2009$

Rest of Country

2009$

13 866 889 1,122 860

13.5 881 906 1,142 875

14 886 914 1,150 880

14.5 888 919 1,155 880

15 885 910 1,146 877

15.5 873 891 1,125 863

16 872 896 1,128 862

16.5 855 883 1,104 850

17 830 861 1,069 830

18 907 937 1,147 925

DOE determined the total installed cost of the combined system based on the SEER level 

of the split system air conditioner plus the cost of an electric furnace. Table 9-B.2.4 through 

Table 9-B.2.7 show the cost differential between the split system central air conditioners plus 

electric furnaces and split system heat pumps in the South Hot-Humid region, the South Hot-Dry 

region, the North region, and nationally. DOE assumed that a negative total installed cost 

difference indicates that there would be no equipment switching (gray areas of the tables). For 

simplicity the total installed cost difference between the same efficiency levels is assumed to be 

zero (efficiency levels 0 through 4). After efficiency level 5 for split system air conditioners, the 

installation of a multispeed or variable speed motor was added so that the higher efficiency could

be achieved.

Table 9-B.2.4 Total Installation Cost Differential, South Hot-Humid (2009$)

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0 87 175 268 359 449 578 672 766 960 1,129 1,251 1,438 1,517 

1 (87) 0 88 180 272 361 491 585 679 873 1,042 1,164 1,351 1,430 

2 (175) (88) 0 92 184 273 403 497 591 785 954 1,076 1,263 1,342 

3 (268) (180) (92) 0 92 181 311 404 498 692 861 983 1,170 1,249 

4 (359) (272) (184) (92) 0 89 219 313 407 601 770 892 1,079 1,158 

5 (1,709)(1,621)(1,533)(1,441)(1,349) (1,260) (1,130) (1,036) (943) (749) (580) (458) (271) (191)

6 (1,838)(1,751)(1,663)(1,571)(1,479) (1,390) (1,260) (1,166) (1,072) (878) (709) (587) (400) (321)

7 (1,932)(1,845)(1,757)(1,664)(1,573) (1,484) (1,354) (1,260) (1,166) (972) (803) (681) (494) (415)

8 (2,026)(1,939)(1,851)(1,758)(1,667) (1,577) (1,448) (1,354) (1,260) (1,066) (897) (775) (588) (509)

9 (2,220)(2,133)(2,045)(1,952)(1,861) (1,771) (1,642) (1,548) (1,454) (1,260) (1,091) (969) (782) (703)
9-B-5

Table 9-B.2.5 Total Installation Cost Differential, South Hot-Dry (2009$)

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0 68 137 209 280 350 453 527 602 757 875 958 1,089 1,139 

1 (68) 0 69 141 212 282 385 459 534 689 807 890 1,021 1,071 

2 (137) (69) 0 72 143 214 316 391 465 621 739 821 953 1,002 

3 (209) (141) (72) 0 71 142 244 319 393 549 667 749 881 930 

4 (280) (212) (143) (71) 0 70 173 247 322 477 595 678 809 859 

5 (1,250) (1,182) (1,114) (1,042) (970) (900) (797) (723) (648) (493) (375) (292) (161) (111)

6 (1,353) (1,285) (1,216) (1,144) (1,073) (1,003) (900) (826) (751) (595) (477) (395) (264) (214)

7 (1,427) (1,359) (1,291) (1,219) (1,147) (1,077) (974) (900) (826) (670) (552) (469) (338) (288)

8 (1,502) (1,434) (1,365) (1,293) (1,222) (1,152) (1,049) (974) (900) (744) (626) (544) (413) (363)

9 (1,657) (1,589) (1,521) (1,449) (1,377) (1,307) (1,205) (1,130) (1,056) (900) (782) (700) (568) (519)

Table 9-B.2.6 Total Installation Cost Differential, North (2009$)

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0 67 136 208 279 350 453 528 603 761 877 964 1,091 1,154 

1 (67) 0 68 140 212 282 385 460 535 693 809 897 1,024 1,087 

2 (136) (68) 0 72 144 214 317 392 467 625 741 829 956 1,019 

3 (208) (140) (72) 0 72 142 245 320 395 553 669 757 884 947 

4 (279) (212) (144) (72) 0 71 174 249 324 481 597 685 812 875 

5 (1,350) (1,282) (1,214) (1,142) (1,071) (1,000) (897) (822) (747) (589) (473) (385) (258) (195)

6 (1,453) (1,385) (1,317) (1,245) (1,174) (1,103) (1,000) (925) (850) (692) (576) (489) (361) (299)

7 (1,528) (1,460) (1,392) (1,320) (1,249) (1,178) (1,075) (1,000) (925) (767) (651) (564) (436) (374)

8 (1,603) (1,535) (1,467) (1,395) (1,324) (1,253) (1,150) (1,075) (1,000) (842) (726) (639) (511) (449)

9 (1,761) (1,693) (1,625) (1,553) (1,481) (1,411) (1,308) (1,233) (1,158) (1,000) (884) (796) (669) (606)

Table 9-B.2.7 Total Installation Cost Differential, National (2009$)

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0 71 142 217 292 365 472 549 627 788 915 1,007 1,148 1,207 

1 (71) 0 71 147 221 294 401 479 556 718 845 936 1,077 1,136 

2 (142) (71) 0 75 150 223 330 407 485 646 773 865 1,005 1,065 

3 (217) (147) (75) 0 75 148 255 332 409 571 698 790 930 990 

4 (292) (221) (150) (75) 0 73 180 257 335 496 623 715 856 915 

5 (1,415)(1,344)(1,273)(1,198)(1,123)(1,050) (943) (866) (788) (627) (500) (408) (267) (208)

6 (1,522)(1,451)(1,380)(1,305)(1,230)(1,157)(1,050) (973) (895) (734) (606) (515) (374) (315)

7 (1,599)(1,529)(1,457)(1,382)(1,307)(1,234)(1,127)(1,050) (973) (811) (684) (592) (452) (392)

8 (1,677)(1,606)(1,535)(1,459)(1,385)(1,312)(1,205)(1,127) (1,050) (888) (761) (670) (529) (470)

9 (1,838)(1,768)(1,696)(1,621)(1,546)(1,473)(1,366)(1,289) (1,212) (1,050) (923) (831) (691) (631)
9-B-6

9-B.2.2.2 Calculation of Operating Cost Savings

For the calculation of the equipment switching payback, DOE used the 10,000 run

simulation for the LCC analysis to extract the operating costs results for each split system heat 

pump household in order to capture cooling and heating differences in operating costs at the 

household level. The calculation of operating costs for each sampled household is described in 

chapter 8 for central air conditioners and heat pumps. The operating cost difference does not 

include maintenance or repair costs, because the differences in these costs are small and are 

usually not part of the consumer’s main criteria for switching equipment types.

For those split system heat pump consumers switching to a combination split system air 

conditioners and electric furnace, DOE determined the space-cooling annual energy use or unit 

energy consumption (UEC) of the air conditioner by multiplying the split system heat pump 

space-cooling UEC by the ratio of the heat pump SEER to the air conditioner SEER. DOE 

determined the space-heating UEC of the electric furnace by multiplying the split system heat 

pump space-heating UEC by the ratio of the heat pump HSPF to the electric furnace efficiency.

(A coefficient of performance (COP) of 1.0 is equivalent to a 3.412 HSPF.)

9-B.2.3 Determination of Payback Criteria for Equipment Switching

To estimate the likelihood of equipment switching between these two systems, DOE 

utilized proprietary data from Decision Analysts 2008 American Home Comfort Study,

1 which 

identified for a representative sample of consumers their willingness to purchase more efficient 

space-conditioning systems. Almost 24,000 homeowners with central heating and/or cooling 

systems were asked, “How much would you be willing to spend to improve energy efficiency (of 

the heating and/or cooling equipment) by 25 percent”? The average amount homeowners were 

willing to spend was $832 in 2008$. DOE assumed that this value was equivalent to how much 

consumers were willing to spend for a 25 percent decrease in their annual heating and cooling 

bill. DOE then used data from RECS 20052 to calculate a national average annual heating and 

cooling bill equal to $928 in 2008$. Then DOE divided the $832 (the value that consumers are 

willing to spend for 25 percent more efficient heating and/or cooling equipment) by 25 percent 

of the $928 average heating and cooling bill (or $232) This results in an average PBP of 3.6

years, which was used as the fixed value to determine if a household would be willing to switch.

Other studies seem to point to higher paybacks. A NFO Research Incorporated study, the 

1997 Consumer New Home Survey3, surveyed over 60,000 homeowners and asked if they 

“would spend an extra $2,000 for energy-efficient products or features during the construction of 

a new home.” The average PBP results from this study would be at least 7 years. The RCLCO 

study in 2007 4 also asked participants about willingness to pay for more efficient equipment and 

found an average payback of about 4 years. These studies were limited to new construction, so 

were not used in this analysis.
9-B-7

9-B.2.4 Calculation of Cooling and Heating Load Fractions

DOE took into account that the average UEC of the households expected to switch was 

different than the average UEC of all split system heat pump households. DOE developed 

cooling and heating load fractions to describe the fractional difference between the average UEC 

of the households expected to switch compared to the average UEC of all split system heat pump 

households.

The average UEC of all split system heat pump households at the baseline efficiency 

level (13 SEER) by region is shown in Table 9-B.2.8. The resulting cooling and heating load 

fractions are given in sections 9-B.2.6.2 and 9-B.2.6.3, respectively.

Table 9-B.2.8 Average UEC for Split System Heat Pumps at the Baseline Efficiency 

Level (13 SEER) by Region

Region Average UEC

Cooling (kWh) Heating (kWh)

South, Hot-Humid 4,409 1,239

South, Hot-Dry 4,328 3,745

North 1,949 2,810

National 3,590 1,796

9-B.2.5 Treatment of Dual Fuel/Hybrid Systems

DOE took into account that there are a fraction of central heat pump systems that include 

non-weatherized gas furnaces; these are called dual fuel systems or hybrid systems (see Table 9-

B.2.9). For these households, DOE did not consider any switching for the same reasons given in 

section 9-B.3.1 for switching between gas and electric furnaces.

Table 9-B.2.9 Fraction of Dual Fuel/Hybrid Systems

Region Fraction of Dual 

Fuel/Hybrid Systems

South, Hot-Humid 10%

South, Hot-Dry 29%

North 33%

National 16%
9-B-8

9-B.2.6 Summary of Results

9-B.2.6.1 Estimated Percent Switching

Table 9-B.2.10 through Table 9-B.2.13 show the estimated percent switching for each 

efficiency level for split system heat pumps to split system central air conditioners and electric 

furnaces in the South Hot-Humid region, the South Hot-Dry region, the North region, and 

nationally. 

Table 9-B.2.10 Estimated Percent Switching from Split-System Heat Pump to SplitSystem Air-Conditioners and Electric Furnaces, South Hot-Humid

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0% 0% 1% 3% 8% 14% 21% 27% 33% 42% 48% 52% 60% 61%

1 0% 0% 0% 1% 4% 9% 19% 23% 30% 42% 46% 49% 58% 60%

2 0% 0% 0% 0% 1% 5% 15% 20% 25% 39% 45% 47% 56% 58%

3 0% 0% 0% 0% 0% 1% 11% 17% 21% 35% 43% 46% 54% 56%

4 0% 0% 0% 0% 0% 0% 1% 6% 9% 15% 20% 22% 26% 27%

5 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

6 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

7 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

8 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

9 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Table 9-B.2.11 Estimated Percent Switching from Split-System Heat Pump to SplitSystem Air-Conditioners and Electric Furnaces, South Hot-Dry

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0% 0% 0% 0% 0% 0% 2% 6% 6% 10% 17% 17% 22% 22%

1 0% 0% 0% 0% 0% 0% 2% 2% 6% 6% 15% 17% 22% 22%

2 0% 0% 0% 0% 0% 0% 0% 2% 4% 6% 13% 15% 22% 22%

3 0% 0% 0% 0% 0% 0% 0% 1% 2% 6% 10% 13% 20% 21%

4 0% 0% 0% 0% 0% 0% 0% 0% 1% 2% 3% 4% 8% 8%

5 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

6 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

7 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

8 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

9 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%
9-B-9

Table 9-B.2.12 Estimated Percent Switching from Split-System Heat Pump to SplitSystem Air-Conditioners and Electric Furnaces, North

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0% 0% 0% 0% 0% 1% 1% 2% 2% 3% 4% 5% 6% 7%

1 0% 0% 0% 0% 0% 0% 1% 1% 2% 3% 4% 4% 6% 6%

2 0% 0% 0% 0% 0% 0% 1% 1% 1% 2% 3% 4% 5% 6%

3 0% 0% 0% 0% 0% 0% 0% 1% 1% 2% 3% 3% 4% 5%

4 0% 0% 0% 0% 0% 0% 0% 0% 0% 1% 1% 1% 2% 2%

5 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

6 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

7 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

8 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

9 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

Table 9-B.2.13 Estimated Percent Switching from Split-System Heat Pump to SplitSystem Air-Conditioners and Electric Furnaces, National

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0% 0% 0% 1% 1% 2% 6% 9% 10% 16% 20% 23% 26% 28%

1 0% 0% 0% 0% 1% 1% 5% 7% 9% 14% 19% 22% 26% 26%

2 0% 0% 0% 0% 0% 1% 3% 6% 8% 11% 18% 19% 25% 26%

3 0% 0% 0% 0% 0% 0% 1% 4% 6% 10% 15% 18% 23% 24%

4 0% 0% 0% 0% 0% 0% 0% 1% 2% 4% 6% 8% 11% 11%

5 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

6 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

7 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

8 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

9 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

9-B.2.6.2 Cooling Load Fraction

Table 9-B.2.14 through Table 9-B.2.17 show the cooling load fraction for each efficiency 

level for split system central air conditioners and electric furnaces and split system heat pumps in 

the South Hot-Humid region, the South Hot-Dry region, the North region, and nationally. 
9-B-10

Table 9-B.2.14 Cooling Load Fraction, South Hot-Humid

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0.00 0.00 0.06 0.13 0.31 0.44 0.52 0.60 0.63 0.70 0.72 0.72 0.76 0.75

1 0.00 0.00 0.00 0.08 0.19 0.34 0.52 0.56 0.62 0.71 0.73 0.72 0.76 0.76

2 0.00 0.00 0.00 0.00 0.08 0.19 0.49 0.56 0.61 0.72 0.73 0.73 0.77 0.76

3 0.00 0.00 0.00 0.00 0.00 0.08 0.44 0.54 0.57 0.69 0.73 0.73 0.78 0.76

4 0.00 0.00 0.00 0.00 0.00 0.00 0.21 0.45 0.55 0.66 0.74 0.73 0.78 0.77

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 9-B.2.15 Cooling Load Fraction, South Hot-Dry

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0.00 0.00 0.00 0.00 0.00 0.00 0.26 0.52 0.52 0.65 0.75 0.75 0.80 0.80

1 0.00 0.00 0.00 0.00 0.00 0.00 0.26 0.29 0.52 0.53 0.73 0.75 0.80 0.80

2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.26 0.42 0.52 0.69 0.73 0.80 0.80

3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.11 0.26 0.52 0.64 0.69 0.78 0.79

4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.26 0.44 0.52 0.60 0.73 0.73

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 9-B.2.16 Cooling Load Fraction, North

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0.00 0.04 0.04 0.04 0.07 0.10 0.18 0.23 0.27 0.37 0.44 0.47 0.53 0.56

1 0.00 0.00 0.04 0.05 0.05 0.07 0.14 0.20 0.25 0.35 0.41 0.44 0.51 0.53

2 0.00 0.00 0.00 0.05 0.05 0.05 0.10 0.15 0.21 0.32 0.38 0.42 0.48 0.51

3 0.00 0.00 0.00 0.00 0.05 0.05 0.07 0.10 0.16 0.28 0.35 0.39 0.45 0.48

4 0.00 0.00 0.00 0.00 0.00 0.05 0.05 0.07 0.11 0.24 0.31 0.35 0.42 0.44

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
9-B-11

Table 9-B.2.17 Cooling Load Fraction, National

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0.00 0.02 0.02 0.07 0.13 0.26 0.45 0.55 0.58 0.70 0.74 0.76 0.79 0.80

1 0.00 0.00 0.02 0.02 0.07 0.16 0.43 0.51 0.56 0.67 0.73 0.75 0.78 0.79

2 0.00 0.00 0.00 0.02 0.02 0.07 0.32 0.45 0.53 0.62 0.72 0.73 0.77 0.78

3 0.00 0.00 0.00 0.00 0.02 0.02 0.11 0.35 0.46 0.59 0.68 0.72 0.76 0.77

4 0.00 0.00 0.00 0.00 0.00 0.02 0.07 0.15 0.38 0.55 0.63 0.69 0.75 0.76

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9-B.2.6.3 Heating Load Fraction

Table 9-B.2.18 through Table 9-B.2.21 show the heating load fraction for each efficiency 

level for split system central air conditioners and electric furnaces and split system heat pumps in 

the South Hot-Humid region, the South Hot-Dry region, the North region, and nationally. 

Table 9-B.2.18 Heating Load Fraction, South Hot-Humid

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0.00 0.00 0.01 0.06 0.14 0.19 0.25 0.29 0.34 0.39 0.45 0.49 0.56 0.57

1 0.00 0.00 0.00 0.02 0.09 0.15 0.23 0.26 0.30 0.38 0.42 0.45 0.54 0.56

2 0.00 0.00 0.00 0.00 0.02 0.09 0.19 0.23 0.26 0.35 0.41 0.43 0.51 0.54

3 0.00 0.00 0.00 0.00 0.00 0.02 0.15 0.20 0.24 0.33 0.38 0.41 0.48 0.51

4 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.16 0.21 0.29 0.35 0.39 0.44 0.47

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
9-B-12

Table 9-B.2.19 Heating Load Fraction, South Hot-Dry

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0.00 0.00 0.00 0.00 0.00 0.00 0.25 0.49 0.50 0.64 0.75 0.75 0.80 0.80

1 0.00 0.00 0.00 0.00 0.00 0.00 0.25 0.27 0.50 0.50 0.74 0.75 0.80 0.80

2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.25 0.39 0.50 0.70 0.74 0.80 0.80

3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.10 0.25 0.50 0.63 0.70 0.78 0.79

4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.25 0.41 0.50 0.59 0.74 0.74

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 9-B.2.20 Heating Load Fraction, North

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0.00 0.04 0.04 0.04 0.07 0.10 0.18 0.23 0.27 0.37 0.44 0.47 0.53 0.56

1 0.00 0.00 0.04 0.05 0.05 0.07 0.14 0.20 0.25 0.35 0.41 0.44 0.51 0.53

2 0.00 0.00 0.00 0.05 0.05 0.05 0.10 0.15 0.21 0.32 0.38 0.42 0.48 0.51

3 0.00 0.00 0.00 0.00 0.05 0.05 0.07 0.10 0.16 0.28 0.35 0.39 0.45 0.48

4 0.00 0.00 0.00 0.00 0.00 0.05 0.05 0.07 0.11 0.24 0.31 0.35 0.42 0.44

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 9-B.2.21 Heating Load Fraction, National

Efficiency Split Heat Pump

Level 0 1 2 3 4 5 6 7 8 9 10 11 12 13

Split AC + Electric Furnace

0 0.00 0.01 0.01 0.06 0.11 0.25 0.44 0.56 0.58 0.71 0.76 0.77 0.79 0.80

1 0.00 0.00 0.01 0.01 0.06 0.14 0.42 0.51 0.57 0.67 0.74 0.76 0.79 0.79

2 0.00 0.00 0.00 0.01 0.01 0.06 0.32 0.44 0.53 0.63 0.73 0.74 0.79 0.79

3 0.00 0.00 0.00 0.00 0.01 0.01 0.10 0.34 0.45 0.59 0.70 0.73 0.78 0.78

4 0.00 0.00 0.00 0.00 0.00 0.01 0.06 0.13 0.37 0.56 0.63 0.71 0.76 0.77

5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

9 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
9-B-13

9-B.3 EQUIPMENT SWITCHING BETWEEN GAS FURNACES AND 

ELECTRIC SPACE HEATING

Gas furnaces compete with electric space heating equipment to some extent. DOE 

determined that equipment switching from gas furnaces to electric space heating is very unlikely 

based on the lack of electrical space heating in regions with high heating loads and the 

significant increase in cost associated with installing an electric circuit for electrical space 

heating equipment. This section details the analysis that led DOE to conclude that equipment 

switching from gas furnaces to electric space heating is highly unlikely and should not be further 

considered.

9-B.3.1 Heating Energy Use Criteria

Figures 9-B.3.1 and 9-B.3.2 depict the heating energy use in the North and South, 

respectively. These figures show that the majority of households with high heating energy use 

have gas furnaces, in both the North and South region. Electric space heating is extremely rare in 

households with high heating energy use (more than 20 MMbtu/yr), which is what almost all gas 

furnace households consume. 

DOE reviewed the 2005 Residential Energy Consumption Survey (RECS) to assess the 

type of space-heating system utilized by consumers as a function of house heating energy use.

2

Gas furnaces are primarily utilized in households with high heating energy use, while electric 

space heating systems are almost exclusively used in households with low heating energy use. 

Generally, this is because the operating costs of electric space heating systems are relatively high 

due to the price of electricity, so using an electric system in a cold climate is significantly more 

expensive than using a gas furnace. For example, a household using 20 MMBtu/h of natural gas

would incur costs from $200 to $300, while an electric furnace satisfying the same heating load 

would cost from $400 to $850. Based on this finding, DOE inferred that consumers with high 

heating loads would be unlikely to switch to electric space heating systems as a result of 

amended standards.
9-B-14

Figure 9-B.3.1 Heating Energy Use—North Region

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

Number of Households

Heating Energy Use (MMbtu/yr)

Electric Furnace

Gas Furnace

Oil and Other Fuel Furnace

Electric Heat Pump
9-B-15

Figure 9-B.3.2 Heating Energy Use—South Region

9-B.3.2 Installation Costs

Replacing a gas furnace with electric space heating incurs substantial costs, because of 

the complexity involved in modifying the installation. DOE determined that installing an electric 

circuit capable of managing an electric space heating system is prohibitively expensive, and this 

is, therefore, a second reason why equipment switching from gas furnaces to electric space 

heating is unlikely. For a household with a gas furnace to switch to electric space heating, a 

separate circuit up to 120-amps would be needed, depending on the house heating design 

requirements, as shown in Table 9-B.3.1. The cost to install such a circuit would vary from

approximately $293 to $608 (see Table 9-B.3.2 and Table 9-B.3.3) based on estimates using RS 

Means Residential Cost Data.

5

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

0-5

10-1520-2530-3540-4550-5560-6570-7580-8590-95

100-105115-120125-130135-140155-160

Number of Households

Heating Energy Use (MMbtu/yr)

Electric Furnace

Gas Furnace

Oil and Other Fuel Furnace

Other Heating Epq

Electric Heat Pump

No Heating Eqp
9-B-16

Table 9-B.3.1 Common Residential Electric Furnace (Single Phase) Sizes and Single 

Circuit Heater Amps, Compared to Equivalent Gas Furnace Shipments 

by Input Capacity

Electric Furnace* Non-Weatherized Gas Furnaces

Input Capacity Heat Amps 

(230V)

Comparable Input 

Capacity Range 

(kBtu/h)

Furnace 

Shipments 

(GAMA, 2001) (kW at 240V) (kBtu/h)

3 10.2 12

5 17.1 20

8 27.3 32

9 30.7 36

10 34.1 40 40-55 9.4%

15 51.2 60 55-70 8.6%

20 68.2 80 70-90 38.5%

24 81.9 96 90-110 23.2%

30 102.4 120 >110 20.4%

* Source: Bryant Model Series FH4C6 and GAMA historical furnace shipments by input 

capacity.7

Table 9-B.3.2 Installation Costs for Adding a 50 amp Electrical Outlet for Electric 

Furnace

Description Crew Labor

Hours Unit

Bare Costs (2009$) Total incl. 

Material Labor Total O&P (2009$)

Trip Charge 1 ELEC* 0.500 Ea. 0 16 16 27

50 amp-240 volt 

receptacle, 30’ of #8/2

(EMT & wire)

1 ELEC 2.703 Ea. 111 89 200 266

Total 3.203 111 105 216 293

* 1 ELEC means a crew of 1 electrician.

Table 9-B.3.3 Installation Costs for Adding a 100 amp Electrical Outlet for Electric 

Furnace

Description Crew Labor

Hours Unit

Bare Costs (2009$) Total incl. 

Material Labor Total O&P

Trip Charge 1 ELEC* 0.50 Ea. 0 16 16 27

100 amp-240 volt 

receptacle, 30’ of #3/2

(EMT & wire)

1 ELEC 3.406 Ea. 363 112 475 581

Total 3.456 363 128 491 608

* 1 ELEC means a crew of 1 electrician.

Note: These estimates do not include the cost of a new panel board to serve this higher 

amp circuit ($985 -$2,6255

).
9-B-17

In addition, many households that would be potentially interested in switching due to 

high installation costs from a condensing furnace standard would still face the same high 

installation costs. Adding an electric furnace would not preclude having to pay the installation 

costs associated with an orphaned water heater, a problem that can be encountered when 

switching from a non-condensing to a condensing furnace. In 18 percent of all non-weatherized 

gas furnace installations, the contractor encounters an orphaned water heater, which adds on 

average $501 to the total installation cost. 

9-B.3.3 Conclusions

The fraction of households that would have a low heating load (especially in the North) 

to find equipment switching attractive is quite low. Furthermore, even for those households with 

small loads the installation costs are required to switch would be very significant and equipment 

switching to electric furnaces would not solve high installation costs associated with orphaned 

water heaters.
9-B-18

REFERENCES

1. Decision Analysts, 2008 American Home Comfort Study: Online Database Tool, 2009. 

Arlington, Texas. <http://www.decisionanalyst.com/Syndicated/HomeComfort.dai>

2. U.S. Department of Energy: Energy Information Administration, Residential Energy 

Consumption Survey (RECS). 2005. Public use data files. 

http://www.eia.doe.gov/emeu/recs/recspubuse05/pubuse05.html

3. Allen, D. R., Do Consumers Buy Energy Efficiency? Home Energy, 

1998<http://www.homeenergy.org/archive/hem.dis.anl.gov/eehem/98/980311.html>

4. Charles A. Hewlett, S. K., "Who's Buying It?" Market Demand for Green Residential. In 

ULI Developing Green Conference. 2007 

<http://www.rclco.com/archivepdf/May42007939_Who%5Cs_Buying_It.pdf>

5. RS Means Company Inc., RS Means Residential Cost Data. 29th Annual Edition ed. 

2010: Kingston, MA

6. Bryant, Product Data for FH4C: Legacy RNC Series Fan Coil (Sizes 001 thru 004), 

2006. Carrier Co. Catalog No. PDSFH4C.01.2. 

<http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/pdsfh4c.01.2.pd

f>

7. Kendall, M., Appendix A - Furnace Shipments; Appendix B - Boiler. Comment # 24 

submitted to Docket Number: EE-RM/STD-01-350 Shipments, April 10, 2002. GAMA. 

Arlington, VA.