8.5-i

APPENDIX 8.5. ANALYSIS OF ELECTRICITY EFFICIENCY DESIGN OPTIONS 

FOR FURNACES AND BOILERS

TABLE OF CONTENTS

8.5.1 INTRODUCTION ................................................... 8.5-1

8.5.2 ELECTRICITY EFFICIENCY OPTIONS THAT PASSED SCREENING ....... 8.5-1

8.5.3 MANUFACTURING COST .......................................... 8.5-2

8.5.4 CALCULATION OF FURNACE OR BOILER ELECTRICITY CONSUMPTION 

WITH DESIGN OPTIONS, USING DOE TEST PROCEDURE . . . . . . . . . . . . . . . 8.5-2

8.5.5 ELECTRICITY-EFFICIENCY DESIGN OPTIONS CONSIDERED IN THE 

LCC ANALYSIS FOR FURNACES .................................... 8.5-4

8.5.6 ELECTRICITY-EFFICIENCY DESIGN OPTIONS CONSIDERED IN THE 

LCC ANALYSIS FOR BOILERS AND OIL-FIRED EQUIPMENT ........... 8.5-5

8.5.7 RESULTS OF ENERGY CONSUMPTION CALCULATIONS ............... 8.5-6

8.5.8 LCC RESULTS INCLUDING ELECTRICITY-EFFICIENCY DESIGN 

OPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5-23

LIST OF TABLES

Table 8.5.3.1 Incremental Manufacturing Cost of Electricity-Efficiency 

Design Options for Furnaces ..................................... 8.5-2

Table 8.5.3.2 Incremental Manufacturing Cost of Electricity-Efficiency 

Design Options for Hot-Water Boilers and Oil Equipment . . . . . . . . . . . . . . 8.5-2

Table 8.5.4.1 Electricity-Efficiency Design Options for Gas Furnaces ............... 8.5-3

Table 8.5.4.2 Electricity-Efficiency Design Options for Oil-Fired Furnaces and 

Hot-Water Boilers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5-3

Table 8.5.7.1 Non-Weatherized Gas Furnace Energy Use ......................... 8.5-6

Table 8.5.7.2 Mobile Home Furnace Energy Use ............................... 8.5-10

Table 8.5.7.3 Weatherized Furnaces Energy Use ............................... 8.5-13

Table 8.5.7.4 Oil-Furnace Energy Use ....................................... 8.5-16

Table 8.5.7.5 Gas Boiler Energy Use ........................................ 8.5-19

Table 8.5.7.6 Oil Boiler Energy Use ......................................... 8.5-21

Table 8.5.8.1 LCC and PBP Results for Non-Weatherized Gas Furnaces, 

Including Electricity-Efficiency Design Options . . . . . . . . . . . . . . . . . . . . 8.5-23

Table 8.5.8.2 LCC and PBP Results for Weatherized Gas Furnaces, 

Including Electricity-Efficiency Design Options . . . . . . . . . . . . . . . . . . . . 8.5-26

Table 8.5.8.3 LCC and PBP Results for Mobile Home Gas Furnaces, 

Including Electricity-Efficiency Design Options . . . . . . . . . . . . . . . . . . . . 8.5-28

Table 8.5.8.4 LCC and PBP Results for Oil-Fired Furnaces, 

Including Electricity-Efficiency Design Options . . . . . . . . . . . . . . . . . . . . 8.5-30

Table 8.5.8.5 LCC and PBP Results for Hot-Water Gas Boilers, 

Including Electricity-Efficiency Design Options . . . . . . . . . . . . . . . . . . . . 8.5-32
8.5-ii

Table 8.5.8.6 LCC and PBP Results for Hot-Water Oil-fired Boilers, 

Including Electricity-Efficiency Design Options . . . . . . . . . . . . . . . . . . . . 8.5-34

LIST OF FIGURES

Figure 8.5.7.1 Range of Annual Gas Use, Non-Weatherized Gas Furnaces ............. 8.5-8

Figure 8.5.7.2 Range of Winter Electricity Use, Non-Weatherized Gas Furnaces ........ 8.5-8

Figure 8.5.7.3 Range of Summer Electricity Use, Non-Weatherized Gas Furnaces ...... 8.5-9

Figure 8.5.7.4 Range of Annual Gas Use, Mobile Home Furnaces .................. 8.5-11

Figure 8.5.7.5 Range of Winter Electricity Use, Mobile Home Furnaces ............. 8.5-11

Figure 8.5.7.6 Range of Summer Electricity Use, Mobile Home Furnaces ............ 8.5-12

Figure 8.5.7.7 Range of Gas Use, Weatherized Gas Furnaces ...................... 8.5-14

Figure 8.5.7.8 Range of Winter Electricity Use, Weatherized Gas Furnaces ........... 8.5-14

Figure 8.5.7.9 Range of Summer Electricity Use, Weatherized Furnaces ............. 8.5-15

Figure 8.5.7.10 Range of Oil Use, Oil-Fired Furnaces ............................ 8.5-17

Figure 8.5.7.11 Range of Winter Electricity Use, Oil-Fired Furnaces ................ 8.5-17

Figure 8.5.7.12 Range of Summer Electricity Use, Oil-Fired Furnaces ............... 8.5-18

Figure 8.5.7.13 Range of Gas Use, Hot Water Gas Boilers ........................ 8.5-20

Figure 8.5.7.14 Range of Winter Electricity Use, Hot Water Gas Boilers ............. 8.5-20

Figure 8.5.7.15 Range of Annual Oil Use, Hot-Water Oil Boilers ................... 8.5-22

Figure 8.5.7.16 Range of Winter Electricity Use, Hot-Water Oil Boilers .............. 8.5-22

Figure 8.5.8.1 Range of LCC Savings by Design Option for Non-Weatherized 

Gas Furnaces ................................................ 8.5-25

Figure 8.5.8.2 Range of LCC Savings by Design Option for Weatherized Gas Furnaces . 8.5-27

Figure 8.5.8.3 Range of LCC Savings by Design Option for Mobile Home Gas Furnaces 8.5-29

Figure 8.5.8.4 Range of LCC Savings by Design Option for Oil-Fired Furnaces ....... 8.5-31

Figure 8.5.8.5 Range of LCC Savings by Design Option for Hot-Water Gas Boilers .... 8.5-33

Figure 8.5.8.6 Range of LCC Savings by Design Option for Hot-Water Oil-Fired Boilers 8.5-35
8.5-1

APPENDIX 8.5. ANALYSIS OF ELECTRICITY EFFICIENCY DESIGN OPTIONS 

FOR FURNACES AND BOILERS

8.5.1 INTRODUCTION

Residential furnaces and boilers use electricity for the circulating-air fan or circulatingwater pump as well as for other electrical components (see section 3.2 in Chapter 3 for further

discussion). In many applications, the furnace fan is also the air handler for the air conditioner.

As discussed in Chapter 1, the Department has determined that it does not have the

authority to regulate electricity consumption in residential furnaces and boilers. While it

was considering this issue, the Department analyzed all design options that met the

screening criteria, including design options specific to saving electricity. The Department

presents the analysis of these design options in this appendix only for the purposes of (a)

full reporting to the public of that complete analysis, and (b) making the information

available for possible use in voluntary or other non-regulatory efforts by manufacturers,

utilities and other interested parties. This appendix is provided for information only.

To develop more information, DOE tested various circulating-air blowers in a commonsize furnace using the Air Movement and Control Association test standard 210 (AMCA 210) as

a method of determining the airflow capacity of a furnace circulating-air blower. Appendix 8.6

describes this testing.

8.5.2 ELECTRICITY EFFICIENCY OPTIONS THAT PASSED SCREENING

As described in Chapter 4, several design options specific to saving electricity in furnaces

and boilers passed the screening. These are:

• Increased motor efficiency: applies to furnace blowers and hot-water boiler pumps. DOE

considered (1) an improved permanent split-capacitor (PSC) motor, which uses improved

materials and design and is slightly more efficient, (2) an electronically-commutated

motor (ECM), and (3) a switched-reluctance motor.

• Increased blower impeller efficiency: substitutes a backward-inclined blade blower for a

forward-inclined blade design, increasing furnace volume and shipping weight. 

• Improved circulating pump (boilers only): uses an ECM for the circulating pump.

• Electronic (interrupted) ignition: applies to oil-fired equipment.
8.5-2

8.5.3 MANUFACTURING COST 

Through discussion with component suppliers and consultants, and review of available

literature, the Department estimated production costs for each of the electricity efficiency

options assuming high-volume production (Tables 8.5.3.1 and 8.5.3.2). For the ECM, the cost

could decrease to the $80 range after 2012, due to increased competition and incremental

technology improvements. The switched-reluctance motor has the potential to be a lower cost

option, but within the time span of this rulemaking, the technology is assumed to have the same

cost as an ECM.

Table 8.5.3.1 Incremental Manufacturing Cost of Electricity-Efficiency Design Options for

Furnaces*

Design Option $

More-efficient PSC motor 5

Electronically-commutated motor 103

Switched-reluctance motor 103

Improved blower impeller 68 **

*

 Relative to baseline equipment.

** $49 additional production cost + $19 additional transportation cost due to larger size of the furnace cabinet

Table 8.5.3.2 Incremental Manufacturing Cost of Electricity-Efficiency Design Options for

Hot-Water Boilers and Oil Equipment*

Design Option $

Boilers: Improved circulating pump (using an ECM) 103

Oil Equipment: Interrupted ignition 17

*

 Relative to baseline equipment.

8.5.4 CALCULATION OF FURNACE OR BOILER ELECTRICITY CONSUMPTION

WITH DESIGN OPTIONS, USING DOE TEST PROCEDURE

The electricity consumption of residential furnaces and boilers is represented by the

Annual Auxiliary Electrical Energy (EAE) parameter, which DOE calculated and reported in

kWh/yr in accordance with the DOE test procedure, section 10.2.3. The details of the approach

to calculate electricity consumption are reported in Appendix 6.3.

EAE does not include blower operation for the air conditioner during the cooling season. 

In fact, the circulating-air blower (which is part of the furnace) is also the air handler for the air

conditioner, and any efficiency improvement on the circulating-air blower will also provide
8.5-3

electricity savings during the cooling season. The Department accounted for this in the LCC

analysis to accurately show the effect of improving furnace electricity efficiency. 

For each AFUE level above the baseline, DOE considered several electricity-efficiency

design options. The selected design options for the different product classes are shown in the

tables below.

Table 8.5.4.1 Electricity-Efficiency Design Options for Gas Furnaces

Product Class Improved

Blower Motor

(PSC+)

Improved

Blower Motor

(ECM)

Improved

Blower Motor

(SR)

Improved

Blower

Impeller

Non-Weatherized Gas

Furnaces X X XX

Weatherized Gas Furnaces X

Mobile Home Gas Furnaces X

Table 8.5.4.2 Electricity-Efficiency Design Options for Oil-Fired Furnaces and Hot-Water

Boilers

Product Class Improved

Blower/Pump Motor

(ECM)

Interrupted Ignition

Oil-Fired Furnaces X X

Hot-Water Gas Boilers X

Hot-Water Oil-Fired Boilers X

The calculation of electricity consumption starts with the calculation of EAE in

accordance with the DOE test procedure. At each AFUE level, the analysis yields a percentage

reduction in electricity consumption associated with each electricity-efficiency design option. 

When an electricity-efficiency design option is introduced, there is usually a small increase in

fuel consumption because a more efficient motor generates less heat, which otherwise would

contribute to the heating requirements. To develop a better understanding of the performance of

more efficient blower/motor combinations, DOE conducted testing. Appendix 6.6 presents a

summary of the testing results.

Generally, inclusion of electricity-efficiency design options slightly increases the

payback period for a given AFUE level relative to use of baseline electricity features, since more

efficient electrical components generate less waste heat.
8.5-4

8.5.5 ELECTRICITY-EFFICIENCY DESIGN OPTIONS CONSIDERED IN THE LCC

ANALYSIS FOR FURNACES 

The baseline design for the furnace circulating-air blower is a forward-curved centrifugal

blower powered by a PSC induction motor. In the LCC Analysis, DOE considered three design

options to improve blower efficiency: 1) an improved PSC motor (PSC+); 2) an ECM; and 3) a

backward-curved blower impeller with a different ECM motor (BC/ECM+). DOE did not

conduct any LCC analysis for the switched reluctance motor because it may be less efficient than

the ECM motor and may be more costly.

The PSC+ is a motor with a dedicated lamination design using higher-grade electrical

steel and tighter windings, with proportionately more copper to limit winding losses. ECM

motors have permanent magnets on the rotor. By changing the frequency and voltage on the

stator coils, the speed and torque of the motor can be adjusted. The BC/ECM+ motor operates at

a higher speed, has a smaller diameter, and has improved magnets and electronics.

Furnaces with ECM or BC/ECM+ blower motors are programmed to take advantage of

the adjustable speed and torque of ECM motors to provide constant airflow, regardless of the

static pressure. This is the equivalent of a vertical fan curve at the nominal airflow of the

furnace.

Chapter 7 describes the general approach for calculating furnace blower electricity

consumption. A full accounting of the impact of electricity-efficiency design options requires

consideration of blower electricity consumption in the heating season and in the cooling season

when an air conditioner may be in use.

Section 7.5.4 in Chapter 7 describes the approach for calculating blower electricity

consumption (BE) for baseline furnaces. Although the approach generally applies to the blower

efficiency design options, the calculation of BE varies somewhat with each design option.

For the PSC+ design option,

BE

AHP

overall scalar = η ×

where:

AHP = air horsepower (W),

η overall = overall efficiency, and

scalar = the incremental motor efficiency gain from the PSC+ design option.

AHP and 0overall depend on static pressure and airflow, as described in section 7.5.3. on

Overall Air-Moving Efficiency.
8.5-5

For the ECM design option, the Department developed a series of equations to calculate

the blower speed and shaft power from the furnace static pressure, the blower-motor efficiency

from the shaft power and speed, and the blower-motor power consumption from the efficiency

and shaft power. The Department developed these equations for ECM motors from the product

literature of a motor manufacturer.1

 See Appendix 8.7, Power Consumption of ECM BlowerMotors.

For the BC/ECM+ design option, the Department developed an equation for BE as a

function of static pressure and airflow from a prototype backward-inclined blower developed by

General Electric.2 The static pressure and airflow is determined from the intersection of the duct

system curve and the vertical fan curve of a furnace, as with an ECM motor. This is explained

further in Appendix 8.8, Power Consumption of BC/ECM+ Blower-Motors.

Section 7.6.2 of Chapter 7 describes the calculation of furnace electricity consumption

during the summer when the blower moves the air cooled by the air conditioner. More-efficient

blower design options will reduce the amount of heat from the blower and blower motor added

to the cooled airstream. However, the annual household cooling load does not change. The

cooling provided by the air-conditioning system, including the furnace blower, must remain the

same, so the air-conditioner operating hours are reduced. See Appendix 8.9, Air Conditioner

Operating Hours, for the derivation of these calculations. The Department calculated the new

air-conditioner operating hours as:

ACOHnew

ACOHexist

BEexist BEnew

ACcapacity

=

+ ×

⎛ −

⎝

⎜ ⎞

⎠ 1 3412 . ⎟

where:

BE = blower motor power (W), and

ACcapacity = cooling capacity of the air conditioner (Btu/h).

8.5.6 ELECTRICITY-EFFICIENCY DESIGN OPTIONS CONSIDERED IN THE LCC

ANALYSIS FOR BOILERS AND OIL-FIRED EQUIPMENT

The power consumption of the circulating pump motor for hot-water boilers is fixed at 62

watts for the baseline design. The improved circulating pump with ECM would reduce pump

power by 32 percent3

 or from 62 to 42 watts.

For oil-fired furnaces and boilers, the LCC analysis considered interrupted ignition. DOE

estimated the electricity savings from interrupted ignition based on a reduction of the on-time of

the burner interrupted ignition device from 3.87 min/cycle (for intermittent ignition) to 0.75

min/cycle.
8.5-6

8.5.7 RESULTS OF ENERGY CONSUMPTION CALCULATIONS

The average energy use for each design option for non-weatherized gas furnaces is shown

in Table 8.5.7.1. The range of annual gas use for non-weatherized gas furnaces for all design

options is shown in Figure 8.5.7.1. Figures 8.5.7.2 and 8.5.7.3 show the range of winter and

summer electricity consumption, respectively. 

Table 8.5.7.1 Non-Weatherized Gas Furnace Energy Use

Design Option

(AFUE and technology

description)

Average Annual Gas

Use (MMBtu)

Average Winter

Electricity Use

(kWh)

Average Summer

Electricity Use

(kWh)

78% Baseline 66.4 488.0 156.7 

80% 64.8 476.2 156.7 

80% PSC+ 64.8 459.1 148.9 

80% ECM 65.5 299.8 117.9 

80% BC/ECM+ 65.8 239.8 77.3 

80% 2-stage Mod. 63.4 475.4 156.7 

80% 2-stage Mod. ECM 64.8 246.1 117.9 

80% 2-stage Mod. BC/ECM+ 65.3 200.6 77.3 

81% 8% Cat. III 64.1 469.8 153.9

81% PSC+ 64.1 453.6 148.9 

81% ECM 64.7 296.2 117.9 

81% BC/ECM+ 65.0 236.9 77.3 

81% 2-stage Mod, no Cat. III 62.7 469.8 156.7 

81% 2-stage Mod ECM 64.0 243.2 117.9 

81% 2-stage Mod BC/ECM+ 64.5 198.2 77.3 

82% 63.2 464.9 156.7 

82% PSC+ 63.3 448.2 148.9 

82% ECM 63.9 292.6 117.9 

82% BC/ECM+ 64.2 234.0 77.3 

82% 2-stage Mod 62.0 464.4 156.7 

82% 2-stage Mod ECM 63.3 240.3 117.9 

82% 2-stage Mod BC/ECM+ 63.7 195.8 77.3 

83% 62.5 459.4 156.7 
Design Option

(AFUE and technology

description)

Average Annual Gas

Use (MMBtu)

Average Winter

Electricity Use

(kWh)

Average Summer

Electricity Use

(kWh)

8.5-7

90% Baseline Cond. 57.8 421.1 156.7 

90% PSC+ 57.9 406.6 148.9 

90% ECM 58.3 277.6 117.9 

90% BC/ECM+ 58.5 224.1 77.3 

91% 2-stage Mod ECM 57.2 238.5 117.9 

91% 2-stage Mod BC/ECM+ 57.5 197.4 77.3 

91% Step Mod ECM 56.8 236.9 117.9 

91% Step Mod BC/ECM+ 57.3 196.4 77.3 

92%Incr. HX Area 56.6 412.2 156.7 

92% PSC+ 56.6 397.9 148.9 

92% ECM 57.1 271.7 117.9 

92% BC/ECM+ 57.3 219.2 77.3 

93% 2-stage Mod ECM 56.0 233.5 117.9 

93% 2-stage Mod BC/ECM+ 56.3 193.2 77.3 

93% Step Mod ECM 55.6 231.9 117.9 

93% Step Mod BC/ECM+ 56.1 192.3 77.3 

96% Step Mod ECM 53.9 224.9 117.9 

96% Step Mod BC/ECM+ 54.3 186.4 77.3 
8.5-8

Annual Gas Use Ranges By Design Option

78%

80% Incr. HX Area

80% PSC+

80% ECM

80% BC/ECM+

80% 2-stage Mod

80% 2-stage Mod ECM

80% 2-stage Mod BC/ECM+

81% wtih 8% Cat. III

81% no Cat. III

81% PSC+

81% ECM

81% BC/ECM+

81% 2 stage Mod, 8% Cat. III

81% 2 stage Mod, no Cat. III

81% 2 stage Mod ECM

81% 2 stage Mod BC/ECM+

90% Baseline Cond.

90% PSC+

90% ECM

90% BC/ECM+

91% 2 stage Mod ECM

91% 2 stage Mod BC/ECM+

91% Step Mod ECM

91% Step Mod BC/ECM+

92% Incr. HX Area

92% PSC+

92% ECM

92% BC/ECM+

93% 2 stage Mod ECM

93% 2 stage Mod BC/ECM+

93% Step Mod ECM

93% Step Mod BC/ECM+

96% Step Mod ECM

96% Cont Mod BC/ECM+

0

20

40

60

80

100

120

140

160

Median

Mean

Figure 8.5.7.1 Range of Annual Gas Use, Non-Weatherized Gas

Furnaces

Winter Electricity Use Ranges By Design Option

78%

80% Incr. HX Area

80% PSC+

80% ECM

80% BC/ECM+

80% 2-stage Mod

80% 2-stage Mod ECM

80% 2-stage Mod BC/ECM+

81% with 8% Cat. III

81% no Cat. III

81% PSC+

81% ECM

81% BC/ECM+

81% 2 stage Mod, 8% Cat. III

81% 2 stage Mod, no Cat. III

81% 2 stage Mod ECM

81% 2 stage Mod BC/ECM+

90% Baseline Cond.

90% PSC+

90% ECM

90% BC/ECM+

91% 2 stage Mod ECM

91% 2 stage Mod BC/ECM+

91% Step Mod ECM

91% Step Mod BC/ECM+

92% Incr. HX Area

92% PSC+

92% ECM

92% BC/ECM+

93% 2 stage Mod ECM

93% 2 stage Mod BC/ECM+

93% Step Mod ECM

93% Step Mod BC/ECM+

96% Step Mod ECM

96% Cont Mod BC/ECM+

-200

0

200

400

600

800

1000

1200

Median

Mean

Figure 8.5.7.2 Range of Winter Electricity Use, NonWeatherized Gas Furnaces
8.5-9

Summer Electricity Use Ranges By Design Option

78%

80% Incr. HX Area

80% PSC+

80% ECM

80% BC/ECM+

80% 2-stage Mod

80% 2-stage Mod ECM

80% 2-stage Mod BC/ECM+

81% with 8% Cat. III

81% no Cat. III

81% PSC+

81% ECM

81% BC/ECM+

81% 2 stage Mod, with 8% Cat. III

81% 2 stage Mod, no Cat. III

81% 2 stage Mod ECM

81% 2 stage Mod BC/ECM+

90% Baseline Cond.

90% PSC+

90% ECM

90% BC/ECM+

91% 2 stage Mod ECM

91% 2 stage Mod BC/ECM+

91% Step Mod ECM

91% Step Mod BC/ECM+

92% Incr. HX Area

92% PSC+

92% ECM

92% BC/ECM+

93% 2 stage Mod ECM

93% 2 stage Mod BC/ECM+

93% Step Mod ECM

93% Step Mod BC/ECM+

96% Step Mod ECM

96% Cont Mod BC/ECM+

-100

0

100

200

300

400

500

600

Median

Mean

Figure 8.5.7.3 Range of Summer Electricity Use, NonWeatherized Gas Furnaces
8.5-10

The average energy use for each design option for mobile home furnaces is shown in

Table 8.5.7.2. The range of annual gas use for mobile home furnaces for all design options is

shown in Figure 8.5.7.4. Figures 8.5.7.5 and 8.5.7.6 show the range of winter and summer

electricity consumption respectively. 

Table 8.5.7.2 Mobile Home Furnace Energy Use

Design Option

(AFUE and technology description)

Average Annual

Gas Use

(MMBtu)

Average Winter

Electricity Use

(kWh)

Average Summer

Electricity Use

(kWh)

75% Baseline 50.8 374.0 228.7 

80% 45.0 404.5 228.7 

80% ECM 45.8 220.8 126.4 

80% 2-stage Mod 43.9 397.9 228.7 

81% 44.5 399.7 228.7 

81% ECM 45.3 218.2 126.4 

81% 2-stage Mod 43.4 393.3 228.7 

82% 44.0 395.0 228.7 

82% ECM 44.7 215.5 126.4 

82% 2-stage Mod 42.9 388.8 228.7 

90% 40.2 359.2 232.7
8.5-11

Annual Gas Use Ranges By Design Option

75% Baseline

80% Incr HX Area

80% ECM

80% 2-Stage Mod

81% Incr HX Area

81% ECM

81% 2-Stage Mod

82% Incr HX Area

82% ECM

82% 2-Stage Mod

90% Condensing

0

20

40

60

80

100

120

140

Median

Mean

Figure 8.5.7.4 Range of Annual Gas Use, Mobile Home

Furnaces

Winter Electricity Use Ranges By Design Option

75% AFUE

80% Incr HX Area

80% ECM

80% 2-Stage Mod

81% Incr HX Area

81% ECM

81% 2-Stage Mod

82% Incr HX Area

82% ECM

82% 2-Stage Mod

90% Condensing

0

100

200

300

400

500

600

700

800

900

1000

Median

Mean

Figure 8.5.7.5 Range of Winter Electricity Use, Mobile Home

Furnaces
8.5-12

Summer Electricity Use Ranges By Design Option

75% Baseline

80% Incr HX Area

80% ECM

80% 2-Stage Mod

81% Incr HX Area

81% ECM

81% 2-Stage Mod

82% Incr HX Area

82% ECM

82% 2-Stage Mod

90% Condensing

-100

0

100

200

300

400

500

600

700

800

Median

Mean

Figure 8.5.7.6 Range of Summer Electricity Use, Mobile Home

Furnaces
8.5-13

The average energy use for each design option for weatherized furnaces is shown in

Table 8.5.7.3. The range of annual gas use for weatherized furnaces for all design options is

shown in Figure 8.5.7.7. Figures 8.5.7.8 and 8.5.7.9 show the range of winter and summer

electricity consumption respectively. 

Table 8.5.7.3 Weatherized Furnaces Energy Use

Design Option

(AFUE and technology description)

Average Annual

Gas Use (MMBtu)

Average Winter

Electricity Use

(kWh)

Average Summer

Electricity Use

(kWh)

78% Baseline 40.3 298.2 372.2 

80% Incr. HX Area 39.3 291.0 372.2 

80% Improved Insulation 39.1 289.9 372.2 

80% PSC+ 39.3 280.7 353.7 

80% ECM 39.7 182.2 281.2 

80% Improved Heat Xfer 39.3 291.0 372.2 

81% Incr. HX Area 38.8 287.5 372.2 

81% Improved Insulation 38.7 286.4 372.2 

81% PSC+ 38.9 277.4 353.7 

81% ECM 39.3 180.0 281.2 

81% Improved Heat Xfer 38.8 287.5 372.2 

82% Incr. HX Area 38.3 284.1 372.2 

82% Improved Insulation 38.2 283.0 372.2 

82% PSC+ 38.4 274.1 353.7 

82% ECM 38.8 177.9 281.2 

82% Improved Heat Xfer 38.3 284.1 372.2 

83% Incr. HX Area 37.9 280.7 372.2 

83% Improved Insulation 37.8 279.7 372.2 

83% PSC+ 37.9 270.8 353.7 

83% ECM 38.3 175.7 281.2 

83% Improved Heat Xfer 37.9 280.7 372.2 
8.5-14

Annual Gas Use Ranges By Design Option

78% Baseline

80% Incr HX Area

80% Improved Insulation

80% PSC+

80% ECM

80% Improved Heat Xfer

81% Incr HX Area

81% Improved Insulation

81% PSC+

81% ECM

81% Improved Heat Xfer

82% Incr HX Area

82% Improved Insulation

82% PSC+

82% ECM

82% Improved Heat Xfer

83% Incr HX Area

83% Improved Insulation

83% PSC+

83% ECM

83% Improved Heat Xfer

0

10

20

30

40

50

60

70

80

90

100

Median

Mean

Figure 8.5.7.7 Range of Gas Use, Weatherized Gas Furnaces

Winter Electricity Use Ranges By Design Option

78% Baseline

80% Incr HX Area

80% Improved Insulation

80% PSC+

80% ECM

80% Improved Heat Xfer

81% Incr HX Area

81% Improved Insulation

81% PSC+

81% ECM

81% Improved Heat Xfer

82% Incr HX Area

82% Improved Insulation

82% PSC+

82% ECM

82% Improved Heat Xfer

83% Incr HX Area

83% Improved Insulation

83% PSC+

83% ECM

83% Improved Heat Xfer

0

100

200

300

400

500

600

700

800

Median

Mean

Figure 8.5.7.8 Range of Winter Electricity Use, Weatherized

Gas Furnaces
8.5-15

Summer Electricity Use Ranges By Design Option

78% Baseline

80% Incr HX Area

80% Improved Insulation

80% PSC+

80% ECM

80% Improved Heat Xfer

81% Incr HX Area

81% Improved Insulation

81% PSC+

81% ECM

81% Improved Heat Xfer

82% Incr HX Area

82% Improved Insulation

82% PSC+

82% ECM

82% Improved Heat Xfer

83% Incr HX Area

83% Improved Insulation

83% PSC+

83% ECM

83% Improved Heat Xfer

-200

0

200

400

600

800

1000

1200

1400

Median

Mean

Figure 8.5.7.9 Range of Summer Electricity Use, Weatherized

Furnaces
8.5-16

The average energy use for each design option for oil-fired furnaces is shown in Table

8.5.7.4. The range of annual oil use for all design options is shown in Figure 8.5.7.10. Figures

8.5.7.11 and 8.5.7.12 show the range of winter and summer electricity consumption respectively. 

Table 8.5.7.4 Oil-Furnace Energy Use

Design Option

(AFUE and technology description)

Average Annual

Gas Use (MMBtu)

Average Winter

Electricity Use

(kWh)

Average Summer

Electricity Use

(kWh)

78% Baseline 87.8 787.3 71.3 

80% 85.7 768.1 71.3 

81% Incr. HX Area 84.7 758.9 71.3 

81% Atom Burner 2-stage Mod. 82.6 845.3 71.3 

81% Interrupted Ignition 84.8 727.2 71.3 

81%ImprovedSupplyFanMotor(ECM) 85.6 533.6 57.3 

82% 83.7 749.9 71.3 

82% Atom Burner 2-stage Mod. 81.6 835.6 71.3 

82% Interrupted Ignition 83.8 718.6 71.3 

82%ImprovedSupplyFanMotor(ECM) 84.6 527.2 57.3 

83% 82.7 741.1 71.3 

83% Atom Burner 2-stage Mod. 80.7 826.0 71.3 

83% Interrupted Ignition 82.8 710.1 71.3 

83%ImprovedSupplyFanMotor(ECM) 83.6 520.9 57.3 

84% 81.7 732.5 71.3 

84% Atom Burner 2-stage Mod. 79.8 816.7 71.3 

84% Interrupted Ignition 81.8 701.9 71.3 

84%ImprovedSupplyFanMotor(ECM) 82.6 514.8 57.3 

85% 80.8 724.1 71.3 

85% Atom Burner 2-stage Mod. 78.9 807.1 71.3 

85% Interrupted Ignition 80.9 693.8 71.3 

85%ImprovedSupplyFanMotor(ECM) 81.6 508.9 57.3 
8.5-17

Annual Gas Use Ranges By Design Option

80% Baseline

80% Incr HX Area81% Incr HX Area

81% Atom Burner 2-stage Mod

81% Interrupted Ignition

81% Improved Supply Fan Motor

82% Incr HX Area

82% Atom Burner 2-stage Mod

82% Interrupted Ignition

82% Improved Supply Fan Motor

83% Incr HX Area

83% Atom Burner 2-stage Mod

83% Interrupted Ignition

83% Improved Supply Fan Motor

84% Incr HX Area

84% Atom Burner 2-stage Mod

84% Interrupted Ignition

84% Improved Supply Fan Motor

85% Incr HX Area

85% Atom Burner 2-stage Mod

85% Interrupted Ignition

85% Improved Supply Fan Motor

0

20

40

60

80

100

120

140

160

180

Median

Mean

Figure 8.5.7.10 Range of Oil Use, Oil-Fired Furnaces

Winter Electricity Use Ranges By Design Option

78% Baseline

80% Incr HX Area81% Incr HX Area

81% Atom Burner 2-stage Mod

81% Interrupted Ignition

81% Improved Supply Fan Motor

82% Incr HX Area

82% Atom Burner 2-stage Mod

82% Interrupted Ignition

82% Improved Supply Fan Motor

83% Incr HX Area

83% Atom Burner 2-stage Mod

83% Interrupted Ignition

83% Improved Supply Fan Motor

84% Incr HX Area

84% Atom Burner 2-stage Mod

84% Interrupted Ignition

84% Improved Supply Fan Motor

85% Incr HX Area

85% Atom Burner 2-stage Mod

85% Interrupted Ignition

85% Improved Supply Fan Motor

0

200

400

600

800

1000

1200

1400

1600

1800

Median

Mean

Figure 8.5.7.11 Range of Winter Electricity Use, Oil-Fired

Furnaces
8.5-18

Summer Electricity Use Ranges By Design Option

78% Baseline

80% Incr HX Area81% Incr HX Area

81% Atom Burner 2-stage Mod

81% Interrupted Ignition

81% Improved Supply Fan Motor

82% Incr HX Area

82% Atom Burner 2-stage Mod

82% Interrupted Ignition

82% Improved Supply Fan Motor

83% Incr HX Area

83% Atom Burner 2-stage Mod

83% Interrupted Ignition

83% Improved Supply Fan Motor

84% Incr HX Area

84% Atom Burner 2-stage Mod

84% Interrupted Ignition

84% Improved Supply Fan Motor

85% Incr HX Area

85% Atom Burner 2-stage Mod

85% Interrupted Ignition

85% Improved Supply Fan Motor

-50

0

50

100

150

200

250

300

350

Median

Mean

Figure 8.5.7.12 Range of Summer Electricity Use, Oil-Fired

Furnaces
8.5-19

The average energy use for each design option for hot-water gas boilers is shown in

Table 8.5.7.5. The range of annual gas use for all design options is shown in Figure 8.5.7.13. 

Figure 8.5.7.14 shows the range of winter electricity consumption.

Table 8.5.7.5 Gas Boiler Energy Use

Design Option

(AFUE and technology description)

Average Annual Gas Use

(MMBtu)

Average Winter

Electricity Use (kWh)

80% Baseline 93.5 378.9 

81% 88.8 379.8 

81% 2-stage mod. + Indc Draft 87.4 561.7 

81% Imp Circ Pump 89.0 337.6 

82% 87.7 375.2 

82% 2-stage mod. + Indc Draft 86.4 555.1 

82% Imp Circ Pump 87.9 333.5 

83% Imp Ht Xfer / Elec. Ign 86.7 370.8 

83% 2-stage mod. + Indc Draft 85.4 548.6 

83% Imp Circ Pump 86.9 329.6 

84% 85.7 366.5 

84% 2-stage mod. + Indc Draft 84.4 542.3 

84% Imp Circ Pump 85.8 325.7 

88% 81.8 350.0 

91% 79.3 301.0 

99% 73.0 276.9 
8.5-20

Annual Gas Use Ranges By Design Option

design option not found

81% Imp Ht Xfer/Elec Ign

81% 2-stage Mod + Indc Draft

81% Imp Circ Pump

82% Imp Ht Xfer/Elec Ign

82% 2-stage Mod + Indc Draft

82% Imp Circ Pump

83% Imp Ht Xfer/Elec Ign

83% 2-stage Mod + Indc Draft

83% Imp Circ Pump

84% Imp Ht Xfer/Elec Ign

84% 2-stage Mod + Indc Draft

84% Imp Circ Pump

88% 91% 99% 

-20

0

20

40

60

80

100

120

140

160

180

200

Median

Mean

Figure 8.5.7.13 Range of Gas Use, Hot Water Gas Boilers

Winter Electricity Use Ranges By Design Option

80% Baseline

81% Imp Ht Xfer/Elec Ign

81% 2-stage Mod + Indc Draft

81% Imp Circ Pump

82% Imp Ht Xfer/Elec Ign

82% 2-stage Mod + Indc Draft

82% Imp Circ Pump

83% Imp Ht Xfer/Elec Ign

83% 2-stage Mod + Indc Draft

83% Imp Circ Pump

84% Imp Ht Xfer/Elec Ign

84% 2-stage Mod + Indc Draft

84% Imp Circ Pump

88% 91% 99% 

-200

0

200

400

600

800

1000

1200

Median

Mean

Figure 8.5.7.14 Range of Winter Electricity Use, Hot Water Gas

Boilers
8.5-21

The average energy use for each design option for hot-water oil-fired boilers is shown in

Table 8.5.7.6. The range of annual oil use for oil boilers for all design options is shown in

Figure 8.5.7.15. Figure 8.5.7.16 shows the range of winter electricity consumption.

Table 8.5.7.6 Oil Boiler Energy Use

Design Option

(AFUE and technology description)

Average Annual Gas Use

(MMBtu)

Average Winter

Electricity Use (kWh)

80% Baseline 108.7 381.3 

81% 107.4 376.7 

81% Atom Burner 2-stage Mod. 105.9 566.9 

81% Interrupted Ign 107.5 345.3 

81% Imp Circ Pump 107.5 338.3 

82% 106.1 372.2 

82% Atom Burner 2-stage Mod. 104.6 560.1 

82% Interrupted Ign 106.2 341.1 

82% Imp Circ Pump 106.2 334.2 

83% 104.8 367.7 

83% Atom Burner 2-stage Mod. 103.4 553.6 

83% Interrupted Ign 104.9 337.1 

83% Imp Circ Pump 105.0 330.3 

84% 103.6 363.4 

84% Atom Burner 2-stage Mod. 102.2 547.1 

84% Interrupted Ign 103.7 333.1 

84% Imp Circ Pump 103.7 326.4 

86% 101.2 355.1 

86% Atom Burner 2-stage Mod. 99.9 534.7 

86% Interrupted Ign 101.3 325.4 

86% Imp Circ Pump 101.3 318.9 

90% 97.0 276.4 

95% 91.9 262.0 
8.5-22

Annual Gas Use Ranges By Design Option

80% Baseline

81%

81% Atom 2-stage

81% Inter Ign

81% Imp Circ Pump

82%

82% Atom 2-stage

82% Inter Ign

82% Imp Circ Pump

83%

83% Atom 2-stage

83% Inter Ign

83% Imp Circ Pump

84%

84% Atom 2-stage

84% Inter Ign

84% Imp Circ Pump

86% 

86% Atom 2-stage

86% Inter Ign

86% Imp Circ Pump

90%95%

20

40

60

80

100

120

140

160

180

200

Median

Mean

Figure 8.5.7.15 Range of Annual Oil Use, Hot-Water Oil Boilers

Winter Electricity Use Ranges By Design Option

80% Baseline

81%

81% Atom 2-stage

81% Inter Ign

81% Imp Circ Pump

82%

82% Atom 2-stage

82% Inter Ign

82% Imp Circ Pump

83%

83% Atom 2-stage

83% Inter Ign

83% Imp Circ Pump

84%

84% Atom 2-stage

84% Inter Ign

84% Imp Circ Pump

86% 

86% Atom 2-stage

86% Inter Ign

86% Imp Circ Pump

90%95%

0

200

400

600

800

1000

1200

Median

Mean

Figure 8.5.7.16 Range of Winter Electricity Use, Hot-Water Oil

Boilers
8.5-23

8.5.8 LCC RESULTS INCLUDING ELECTRICITY-EFFICIENCY DESIGN OPTIONS

The calculation of LCC and PBP for equipment with the electricity-efficiency design

options followed the approach described in Chapter 8. For these options, summer electricity

prices were used for calculating the energy cost of summer electricity consumption.

Table 8.5.8.1 shows the LCC and payback results for all design options for nonweatherized gas furnaces. At 80 percent and 81 percent AFUE levels, the improved PSC motor

increases the LCC savings relative to designs with a baseline blower. The ECM and BC/ECM+

options have a negative effect on LCC.

Table 8.5.8.1 LCC and PBP Results for Non-Weatherized Gas Furnaces, Including

Electricity-Efficiency Design Options

LCC Payback

Design Option

(AFUE and technology description)

Average Average

Savings

Net Cost No

Impact*

Net

Benefit

Median Average

**

$ $ % % % years years

78% Baseline $9,966

80% $9,795 $0 0% 99% 1% 2.1 37.8

80% PSC+ $9,784 $7 17% 27% 56% 5.4 5.3

80% ECM $9,873 -$59 60% 27% 14% 23.0 33.7

80% BC/ECM+ $9,822 -$21 51% 27% 23% 17.2 26.3

80% 2-stage mod. $9,718 $41 33% 27% 40% 8.6 13.5

80% 2-mod. ECM $9,795 -$13 48% 27% 26% 15.4 21.1

80% 2-stage mod. BC/ECM+ $9,782 $1 45% 27% 28% 14.3 20.9

81%, 8% Cat. III $9,789 -$3 32% 27% 41% 8.8 27.8

81% PSC+ $9,779 $5 30% 26% 44% 8.1 21.3

81% ECM $9,868 -$62 51% 26% 23% 17.8 26.2

81% BC/ECM+ $9,816 -$24 45% 26% 29% 14.8 22.9

81% 2-stage Mod, no Cat. III $9,680 $63 29% 26% 45% 7.6 17.0

81% 2-stage Mod ECM $9,796 -$20 44% 26% 29% 14.4 21.1

81% 2-stage Mod BC/ECM+ $9,782 -$5 43% 26% 31% 13.7 20.5

82% $10,170 -$292 70% 26% 4% 28.7 84.6

82% PSC+ $10,159 -$284 69% 26% 5% 29.2 80.6

82% ECM $10,249 -$351 71% 26% 3% 48.4 102.4

82% BC/ECM+ $10,197 -$312 68% 26% 6% 34.8 80.3
LCC Payback

Design Option

(AFUE and technology description)

Average Average

Savings

Net Cost No

Impact*

Net

Benefit

Median Average

**

8.5-24

82% 2-stage Mod $10,103 -$256 65% 26% 9% 18.5 60.2

82% 2-stage Mod ECM $10,179 -$310 67% 26% 7% 34.6 82.1

82% 2-stage Mod BC/ECM+ $10,164 -$295 65% 26% 9% 30.9 70.4

83% $10,400 -$468 73% 26% 1% 63.3 121.3

90% Baseline Cond. $9,917 -$154 56% 26% 18% 17.9 42.5

90% PSC+ $9,907 -$145 57% 15% 27% 14.3 37.9

90% ECM $10,007 -$226 66% 15% 19% 21.5 47.0

90% BC/ECM+ $9,957 -$180 63% 15% 22% 19.1 42.0

91% 2-stage Mod ECM $9,898 -$141 58% 15% 26% 16.5 40.6

91% 2-stage BC/ECM+ $9,878 -$118 58% 15% 27% 16.2 37.8

91% Step Mod ECM $10,119 -$328 67% 15% 18% 22.2 54.2

91% Step Mod BC/ECM+ $10,110 -$315 66% 15% 18% 21.6 49.2

92%Incr. HX Area $9,924 -$166 60% 15% 25% 16.1 41.7

92% PSC+ $9,914 -$156 63% 2% 35% 13.2 35.8

92% ECM $10,015 -$255 76% 2% 22% 21.3 45.0

92% BC/ECM+ $9,965 -$205 73% 2% 25% 19.2 39.7

93% 2-stage Mod ECM $9,912 -$154 67% 2% 32% 15.7 39.1

93% 2-stage Mod BC/ECM+ $9,891 -$133 66% 2% 32% 15.7 35.7

93% Step Mod ECM $10,134 -$373 78% 2% 21% 21.6 50.4

93% Step Mod BC/ECM+ $10,124 -$362 77% 2% 21% 21.4 45.1

96% Step Mod ECM $10,724 -$954 89% 2% 9% 32.3 88.9

96% Step Mod BC/ECM+ $10,738 -$967 91% 0% 9% 32.8 83.6

* “No impact” means that the base case furnace assigned to the household has greater efficiency than the

level indicated, so the household is not affected. 

** From the form of the payback calculation, a very small change in operating cost can result in extremely

large paybacks. These extremely large paybacks will skew the average payback. In these cases, median is

probably a better indicator.
8.5-25

LCC Savings Ranges By Design Option

Median; Box: 25%-75%; Whisker: 5%-95%

80%

80% PSC+

80% ECM

80% BC/ECM+

80% 2-stage Mod

81% 8% Cat. III

81% PSC+

81% ECM

81% BC/ECM+

81% 2 stage Mod, no Cat. III

81% 2 stage Mod ECM

81% 2 stage Mod BC/ECM+

90% Baseline Cond.

90% PSC+

90% ECM

90% BC/ECM+

91% 2 stage Mod ECM

91% 2 stage Mod BC/ECM+

91% Step Mod ECM

91% Step Mod BC/ECM+

92%

92% PSC+

92% ECM

92% BC/ECM+

93% 2 stage Mod ECM

93% 2 stage Mod BC/ECM+

93% Step Mod ECM

93% Step Mod BC/ECM+

96% Step Mod ECM

96% Mod BC/ECM+

-$2500

-$2000

-$1500

-$1000

-$500

$0

$500

$1000

$1500

Median

Mean

Figure 8.5.8.1 Range of LCC Savings by Design Option for

Non-Weatherized Gas Furnaces

Figure 8.5.8.1 shows the range of LCC savings for all design options for non-weatherized

gas furnaces. For each design option, the top and the bottom of the box indicate the 75th and 25th

percentiles, respectively. The bar at the middle of the box indicates the median; 50 percent of

the households have LCC savings above this value. The ‘whiskers’ at the bottom and the top of

the box indicate the 5th and 95th percentiles. The small box shows the average LCC savings for

each design option. 
8.5-26

Table 8.5.8.2 shows the results for weatherized gas furnaces. For all considered AFUE

levels, the improved PSC motor increases the LCC savings relative to designs with a baseline

blower. The ECM option has a negative effect on LCC. Figure 8.5.8.2 shows the range of LCC

savings by design option for weatherized gas furnaces.

Table 8.5.8.2 LCC and PBP Results for Weatherized Gas Furnaces, Including ElectricityEfficiency Design Options

Design Option

(AFUE and technology description)

LCC Payback

Average Average

Savings

Net Cost No

Impact*

Net

Benefit

Median Average

**

78% Baseline $8,545

80% Incr. HX Area $8,457 $2 0% 98% 2% 1.1 1.5

80% Improved Insulation $8,454 $4 26% 46% 28% 9.0 8.2

80% PSC+ $8,441 $10 6% 46% 48% 3.4 4.0

80% ECM $8,529 -$37 43% 46% 11% 19.3 26.7

80% Improved Heat Xfer $8,467 -$4 52% 46% 2% 2.8 3.7

81% Incr. HX Area $8,418 $23 2% 46% 52% 2.0 2.6

81% Improved Insulation $8,415 $25 20% 20% 60% 5.2 6.4

81% PSC+ $8,402 $36 4% 20% 76% 2.8 3.4

81% ECM $8,490 -$35 58% 20% 22% 16.0 21.2

81% Improved Heat Xfer $8,424 $18 32% 20% 48% 3.8 5.1

82% Incr. HX Area $8,380 $53 3% 20% 77% 2.1 2.9

82% Improved Insulation $8,377 $56 18% 0% 82% 4.3 5.6

82% PSC+ $8,364 $69 4% 0% 96% 2.6 3.2

82% ECM $8,452 -$19 65% 0% 35% 14.1 18.3

82% Improved Heat Xfer $8,382 $51 24% 0% 76% 2.5 3.4

83% Incr. HX Area $8,347 $86 6% 0% 94% 2.9 3.9

83% Improved Insulation $8,345 $88 11% 0% 89% 3.9 5.5

83% PSC+ $8,331 $102 3% 0% 97% 3.0 3.6

83% ECM $8,420 $13 58% 0% 43% 12.2 15.0

83% Improved Heat Xfer $8,345 $89 4% 0% 96% 2.4 3.3

* “No impact” means that the base case furnace assigned to the household has greater efficiency than the

level indicated, so the household is not affected. 

** From the form of the payback calculation, a very small change in operating cost can result in extremely

large paybacks. These extremely large paybacks will skew the average payback. In these cases, median is

probably a better indicator.
8.5-27

LCC Savings Ranges By Design Option

Median; Box: 25%-75%; Whisker: 5%-95%

80% Incr HX Area

80% Improved Insulation

80% PSC+

80% ECM

80% Improved Heat Xfer

81% Incr HX Area

81% Improved Insulation

81% PSC+

81% ECM

81% Improved Heat Xfer

82% Incr HX Area

82% Improved Insulation

82% PSC+

82% ECM

82% Improved Heat Xfer

83% Incr HX Area

83% Improved Insulation

83% PSC+

83% ECM

83% Improved Heat Xfer

-$300

-$200

-$100

$0

$100

$200

$300

$400

$500

Median

Mean

Figure 8.5.8.2 Range of LCC Savings by Design Option for

Weatherized Gas Furnaces
8.5-28

Table 8.5.8.3 shows the results for mobile home gas furnaces. The ECM option has a

negative effect on LCC. Figure 8.5.8.3 shows the range of LCC savings by design option for

mobile home gas furnaces. 

Table 8.5.8.3 LCC and PBP Results for Mobile Home Gas Furnaces, Including ElectricityEfficiency Design Options

Design Option

(AFUE and technology description)

LCC Payback

Average

LCC

Average

Savings

Net Cost No

Impact*

Net

Benefit

Median Average

**

75% Baseline $7,904

80% $7,480 $64 1% 85% 14% 2.4 4.7

80% ECM $7,568 -$21 67% 5% 28% 20.0 36.1

80% 2-stage modulation $7,718 -$163 80% 5% 15% 26.0 60.5

81% $7,428 $112 10% 5% 85% 4.4 6.3

81% ECM $7,517 $28 57% 5% 38% 15.6 21.1

81% 2-stage modulation $7,670 -$117 75% 5% 20% 24.9 60.3

82% $7,385 $153 14% 5% 81% 5.1 7.5

82% ECM $7,473 $69 49% 5% 46% 13.3 17.4

82% 2-stage modulation $7,630 -$80 70% 5% 25% 22.9 56.3

90% $7,352 $184 46% 5% 49% 12.5 22.7

* “No impact” means that the base case furnace assigned to the household has greater efficiency than the

level indicated, so the household is not affected. 

** From the form of the payback calculation, a very small change in operating cost can result in extremely

large paybacks. These extremely large paybacks will skew the average payback. In these cases, median is

probably a better indicator.
8.5-29

LCC Savings Ranges By Design Option

Median; Box: 25%-75%; Whisker: 5%-95%

80% Incr HX Area

80% ECM

80% 2-Stage Mod

81% Incr HX Area

81% ECM

81% 2-Stage Mod

82% Incr HX Area

82% ECM

82% 2-Stage Mod

90% Condensing

-$600

-$400

-$200

$0

$200

$400

$600

$800

$1000

$1200

$1400

$1600

Median

Mean

Figure 8.5.8.3 Range of LCC Savings by Design Option for

Mobile Home Gas Furnaces

Table 8.5.8.4 shows the results for oil-fired furnaces. Interrupted ignition shows LCC

savings at the 81–83 percent AFUE levels, though slightly less than the designs with baseline

features. The other electricity-efficiency design options also show positive LCC savings in some

cases, but have lower LCC savings than designs with baseline features. Figure 8.5.8.4 shows the

range of LCC savings by design option for oil-fired furnaces. 
8.5-30

Table 8.5.8.4 LCC and PBP Results for Oil-Fired Furnaces, Including ElectricityEfficiency Design Options

Design Option

(AFUE and technology description)

LCC Payback

Average Average

Savings

Net Cost No

Impact*

Net

Benefit

Median Average

**

78% Baseline $16,194

80% Incr. HX Area $15,900 $11 0% 96% 4% 0.2 0.2

81% $15,762 $95 2% 39% 59% 0.4 0.5

81% Atom Burner 2-stage Mod. $15,885 $8 42% 30% 28% 11.7 19.4

81% Interrupted Ignition $15,785 $79 13% 30% 57% 2.8 4.9

81% ECM $15,945 -$33 50% 30% 20% 14.4 22.8

82% $15,625 $190 2% 30% 68% 0.3 0.4

82% Atom Burner 2-stage Mod. $15,753 $89 35% 22% 42% 8.5 13.8

82% Interrupted Ignition $15,648 $173 10% 22% 68% 1.7 3.5

82% ECM $15,807 $49 39% 22% 38% 9.2 16.8

83% $15,492 $293 3% 22% 75% 0.3 0.4

83% Atom Burner 2-stage Mod. $15,626 $178 31% 15% 54% 6.8 11.2

83% Interrupted Ignition $15,515 $273 10% 15% 75% 1.3 2.9

83% ECM $15,674 $138 32% 15% 53% 7.1 14.7

84% $15,967 -$111 58% 15% 27% 13.7 20.8

84% Atom Burner 2-stage Mod. $16,106 -$240 71% 7% 22% 16.3 25.1

84% Interrupted Ignition $15,990 -$133 66% 7% 26% 14.4 21.2

84% ECM $16,148 -$279 74% 7% 18% 17.6 32.8

85% $15,845 $1 49% 7% 44% 10.0 13.8

85% Atom Burner 2-stage Mod. $15,989 -$143 69% 0% 31% 13.7 20.1

85% Interrupted Ignition $15,868 -$22 58% 0% 42% 10.8 14.9

85% ECM $16,026 -$180 72% 0% 28% 14.6 27.3

* “No impact” means that the base case furnace assigned to the household has greater efficiency than the level indicated,

so the household is not affected. 

** From the form of the payback calculation, a very small change in operating cost can result in extremely large

paybacks. These extremely large paybacks will skew the average payback. In these cases, median is probably a better

indicator.
8.5-31

LCC Savings Ranges By Design Option

80% Incr HX Area81% Incr HX Area

81% Atom Burner 2-stage Mod

81% Interrupted Ignition

81% Improved Supply Fan Motor

82% Incr HX Area

82% Atom Burner 2-stage Mod

82% Interrupted Ignition

82% Improved Supply Fan Motor

83% Incr HX Area

83% Atom Burner 2-stage Mod

83% Interrupted Ignition

83% Improved Supply Fan Motor

84% Incr HX Area

84% Atom Burner 2-stage Mod

84% Interrupted Ignition

84% Improved Supply Fan Motor

85% Incr HX Area

85% Atom Burner 2-stage Mod

85% Interrupted Ignition

85% Improved Supply Fan Motor

-$1200

-$1000

-$800

-$600

-$400

-$200

$0

$200

$400

$600

$800

$1000

$1200

Median

Mean

Figure 8.5.8.4 Range of LCC Savings by Design Option for OilFired Furnaces
8.5-32

Table 8.5.8.5 shows the results for hot-water gas boilers. The improved circulation pump

(with ECM) has a negative effect on LCC. Figure 8.5.8.5 shows the range of LCC savings by

design option for hot-water gas boilers.

Table 8.5.8.5 LCC and PBP Results for Hot-Water Gas Boilers, Including ElectricityEfficiency Design Options

Design Option

(AFUE and technology description)

LCC Payback

Average

LCC

Average

Savings

Net Cost No

Impact*

Net

Benefit

Median Average

**

80% Baseline $10,635

81% $10,371 $93 0% 65% 35% 2.1 2.4

81% 2-stage modulation $10,599 -$36 38% 44% 18% 9.9 14.8

81% Imp Circ Pump $10,620 -$48 41% 44% 16% 15.1 55.9

82% $10,314 $125 3% 44% 53% 2.5 3.3

82% 2-stage modulation $10,542 -$36 48% 30% 22% 9.3 19.6

82% Imp Circ Pump $10,564 -$51 51% 30% 19% 19.1 42.9

83% $10,256 $166 5% 30% 66% 2.5 3.3

83% 2-stage modulation $10,483 -$29 59% 15% 27% 9.9 23.3

83% Imp Circ Pump $10,505 -$46 61% 15% 24% 17.8 39.6

84% $10,199 $215 6% 15% 79% 2.5 3.4

84% 2-stage modulation $10,426 $0 62% 6% 32% 10.5 22.7

84% Imp Circ Pump $10,448 -$20 63% 6% 31% 15.1 31.4

88% $10,741 -$294 67% 6% 27% 17.5 29.8

91% $10,823 -$372 75% 3% 22% 19.3 43.0

99% $11,304 -$853 85% 0% 15% 21.7 46.1

* “No impact” means that the base case furnace assigned to the household has greater efficiency than the

level indicated, so the household is not affected. 

** From the form of the payback calculation, a very small change in operating cost can result in extremely

large paybacks. These extremely large paybacks will skew the average payback. In these cases, median is

probably a better indicator..
8.5-33

LCC Savings Ranges By Design Option

Median; Box: 25%-75%; Whisker: 5%-95%

81% Imp Ht Xfer/Elec Ign

81% 2-stage Mod + Indc Draft

81% Imp Circ Pump

82% Imp Ht Xfer/Elec Ign

82% 2-stage Mod + Indc Draft

82% Imp Circ Pump

83% Imp Ht Xfer/Elec Ign

83% 2-stage Mod + Indc Draft

83% Imp Circ Pump

84% Imp Ht Xfer/Elec Ign

84% 2-stage Mod + Indc Draft

84% Imp Circ Pump

88% 91% 99% 

-$2500

-$2000

-$1500

-$1000

-$500

$0

$500

$1000

$1500

Median

Mean

Figure 8.5.8.5 Range of LCC Savings by Design Option for

Hot-Water Gas Boilers
8.5-34

Table 8.5.8.6 shows the results for hot-water oil-fired boilers. Interrupted ignition shows

LCC savings at the 81–83 percent AFUE levels that are about the same as the designs with

baseline features. The other electricity-efficiency design options have lower LCC savings than

designs with baseline features. Figure 8.5.8.6 shows the range of LCC savings by design option

for hot-water oil-fired boilers.

Table 8.5.8.6 LCC and PBP Results for Hot-Water Oil-fired Boilers, Including ElectricityEfficiency Design Options

Design Option

(AFUE and technology description)

Average Average

Savings

Net Cost No

Impact*

Net

Benefit

Median Average

**

80% Baseline $14,890

81% $14,772 $6 0% 95% 5% 0.6 0.8

81% Atomized Burner $15,166 -$36 11% 89% 0% 70.4 104.9

81% Inter Ign $14,776 $6 4% 89% 7% 6.0 9.4

81% Imp Circ Pump $14,995 -$17 10% 89% 1% 39.5 64.0

82% $14,657 $18 0% 89% 11% 0.7 0.8

82% Atomized Burner $15,051 -$45 16% 84% 0% 35.0 64.3

82% Inter Ign $14,661 $18 4% 84% 12% 3.4 6.7

82% Imp Circ Pump $14,880 -$17 13% 84% 3% 21.1 44.5

83% $14,545 $36 0% 84% 16% 0.7 0.8

83% Atomized Burner $14,939 -$119 37% 61% 2% 23.0 45.0

83% Inter Ign $14,549 $35 16% 61% 23% 7.8 10.1

83% Imp Circ Pump $14,768 -$52 33% 61% 6% 52.8 67.8

84% $14,435 $79 0% 61% 39% 0.7 0.8

84% Atomized Burner $14,830 -$169 58% 37% 5% 26.7 57.6

84% Inter Ign $14,439 $77 17% 37% 46% 3.8 7.4

84% Imp Circ Pump $14,659 -$61 51% 37% 11% 24.1 49.8

86% $14,943 -$234 52% 37% 11% 23.0 31.6

86% Atomized Burner $15,338 -$602 91% 7% 2% 53.0 98.1

86% Inter Ign $14,947 -$238 73% 7% 20% 17.4 24.9

86% Imp Circ Pump $15,167 -$442 88% 7% 5% 41.3 59.3

90% $15,260 -$527 81% 7% 12% 19.6 23.8

95% $15,561 -$829 88% 0% 12% 19.1 23.0

* “No impact” means that the base case furnace assigned to the household has greater efficiency than the level indicated, so the household is

not affected. 

** From the form of the payback calculation, a very small change in operating cost can result in extremely large paybacks. These extremely

large paybacks will skew the average payback. In these cases, median is probably a better indicator.
8.5-35

LCC Savings Ranges By Design Option

Median; Box: 25%-75%; Whisker: 5%-95%

81%

81% Atom 2-stage

81% Inter Ign

81% Imp Circ Pump

82%

82% Atom 2-stage

82% Inter Ign

82% Imp Circ Pump

83%

83% Atom 2-stage

83% Inter Ign

83% Imp Circ Pump

84%

84% Atom 2-stage

84% Inter Ign

84% Imp Circ Pump

86% 

86% Atom 2-stage

86% Inter Ign

86% Imp Circ Pump

90%95%

-$2200

-$2000

-$1800

-$1600

-$1400

-$1200

-$1000

-$800

-$600

-$400

-$200

$0

$200

$400

$600

$800

Median

Mean

Figure 8.5.8.6 Range of LCC Savings by Design Option for

Hot-Water Oil-Fired Boilers