### CHAPTER 11. LIFE-CYCLE COST SUBGROUP ANALYSIS

TABLE OF CONTENTS

11.1 INTRODUCTION

......................................................................................................... 11-1

11.2 SUBGROUPS DEFINITION

........................................................................................ 11-1

11.2.1 Senior–Only Households

............................................................................................... 11-1

11.2.2 Low-Income Households

............................................................................................... 11-1

11.2.3 Multi-Family Households

.............................................................................................. 11-2

11.2.4 Mobile Home Households

............................................................................................. 11-2

11.3 INPUTS TO THE LIFE-CYCLE COST AND PAYBACK PERIOD SUBGROUP

ANALYSIS

.................................................................................................................... 11-2

11.4 RESULTS

...................................................................................................................... 11-5

11.4.1 Water Heaters

................................................................................................................. 11-5

11.4.2 Direct Heating Equipment

............................................................................................. 11-9

11.5 DISCUSSION

.............................................................................................................. 11-11

LIST OF TABLES

Table 11.2.1 RECS 2005 Definitions of Low-Income Households by Yearly Income

.......... 11-2 Table 11.3.1 Household Population Data for Water Heaters

.................................................. 11-3 Table 11.3.2 Household Population Data for Direct Heating Equipment

.............................. 11-3 Table 11.3.3 Gas-Fired Water Heaters: Comparison of Input Values for All Households, Senior-Only, Low-Income, Multi-Family, and Mobile Homes

.... 11-4 Table 11.3.4 Electric Water Heaters: Comparison of Input Values for All Households,

Table 11.3.5 Gas Wall Fan DHE: Comparison of Input Values for All Households,

Table 11.3.6 Gas Wall Gravity DHE: Comparison of Input Values for All Households,

Table 11.4.1 Gas-Fired Storage Water Heaters: LCC and PBP Results for Senior-Only

Table 11.4.2 Gas-Fired Storage Water Heaters: LCC and PBP Results for Low-Income

Table 11.4.3 Gas-Fired Storage Water Heaters: LCC and PBP Results for Multi-Family

Table 11.4.4 Gas-Fired Storage Water Heaters: LCC and PBP Results for Mobile Home

Table 11.4.5 Electric Storage Water Heaters: LCC and PBP Results for Senior-Only

Table 11.4.6 Electric Storage Water Heaters: LCC and PBP Results for Low-Income

Table 11.4.7 Electric Storage Water Heaters: LCC and PBP Results for Multi-Family

Table 11.4.8 Electric Storage Water Heaters: LCC and PBP Results for Mobile Home Senior-Only, Low-Income, Multi-Family, and Mobile Homes

......................... 11-4

Senior-Only, and Low-Income

.......................................................................... 11-4

Senior-Only, and Low-Income

.......................................................................... 11-5

Households

......................................................................................................... 11-5

Households

......................................................................................................... 11-6

Households

......................................................................................................... 11-6

Households

......................................................................................................... 11-7

Households

......................................................................................................... 11-7

Households

......................................................................................................... 11-8

Households

......................................................................................................... 11-8

Households

......................................................................................................... 11-9

11-i

### Table 11.4.9 Gas Wall Fan DHE: LCC and PBP Results for Senior-Only Households

........ 11-9

Table 11.4.10 Gas Wall Fan DHE: LCC and PBP Results for Low-Income Households

...... 11-10 Table 11.4.11 Gas Wall Gravity DHE: LCC and PBP Results for Senior-Only

Households

....................................................................................................... 11-10 Table 11.4.12 Gas Wall Gravity DHE: LCC and PBP Results for Low-Income

Households

....................................................................................................... 11-11

LIST OF FIGURES

Figure 11.5.1 Electric Storage Water Heaters: Average LCC Savings by Subgroup

............ 11-12 Figure 11.5.2 Electric Storage Water Heaters: Households With Net Cost by Subgroup

..... 11-12 Figure 11.5.3 Electric Storage Water Heaters: Median Payback Period by Subgroup

.......... 11-13

11-ii

### CHAPTER 11. LIFE-CYCLE COST SUBGROUP ANALYSIS

11.1 INTRODUCTION

Chapter 8 describes the life-cycle cost (LCC) and payback period (PBP) analyses that examine impacts of energy conservation standards on the U.S. population. In analyzing the potential impact of new or amended standards on residential consumers, DOE further evaluates the impact on identifiable groups of consumers (i.e., subgroups) that may be disproportionately affected by a national standard level. The LCC subgroup analysis evaluates impacts by analyzing the LCC and PBPs for subgroups of residential consumers. For heating products, DOE identified two consumer subgroups that warranted further study: households composed of people 65 years of age or older (senior-only) and households at or below the poverty line (low-income).



### DOE determined the impact on consumer subgroups for heating products using the LCC Spreadsheet Model, which allows for the examination of particular consumer subgroups. DOE has the ability to use the LCC Spreadsheet Model to analyze the LCC for any subgroup by sampling only the data that apply to that subgroup. (Chapter 8 explains in detail the inputs to the model used in determining LCC and PBPs.) As described in section 11.3, the energy use and energy price characteristics of the two subgroups (senior-only and low-income households) are different than that for the general population.

This chapter describes the subgroup identification in further detail and gives the results of the LCC and PBP analyses for gas-fired and electric storage water heaters, and gas wall fan and gas wall gravity DHE.



### 11.2 SUBGROUPS DEFINITION

11.2.1 Senior–Only Households

Senior-only households have occupants who are all at least 65 years of age. Based on the DOE Energy Information Administration (EIA)’s Residential Energy Consumption Survey of 2005 (RECS), senior-only households comprise 17 percent of the country’s households. 1



### 11.2.2 Low-Income Households

As defined in the RECS survey, low-income households are considered to be those at or below the “poverty line.” The “poverty line” varies with household size, head of household age,and family income. Table 11.2.1 summarizes the income level baselines for selecting lowincome households from the RECS sample. The RECS survey classifies 15 percent of the country’s households as low-income.

11-1

### Table 11.2.1 RECS 2005 Definitions of Low-Income Households by Yearly Income Average Income in $

Household Size 48 Contiguous States

and D.C. Alaska Hawaii

1 9,570 11,950 11,010



### 2 12,830 16,030 14,760



### 3 16,090 20,100 18,510



### 4 19,350 24,190 22,260


### 5 22,610 28,270 26,010



### 6 25,870 32,350 29,760



### 7 29,130 36,430 33,510



### 8 32,390 40,510 37,260



### 9 35,650 44,590 41,010



### 10 38,910 48,670 44,760



### 11 42,170 52,750 48,510



### 12 45,430 56,830 52,260



### 13 48,690 60,910 56,010



### 14 51,950 64,990 59,760


### 15 55,210 69,070 63,510



### 11.2.3 Multi-Family Households

Multi-family households are located in buildings with 2 or more units. According to the RECS survey, multi-family households comprise 22 percent of the country’s households. This subgroup was only analyzed for water heaters. It comprises 11.1 percent of the sample used for gas-fire storage water heaters, and 12.1 percent of the sample used for electric storage water

heaters.

11.2.4 Mobile Home Households

According to the RECS survey, households living in mobile homes comprise 6 percent of the country’s households. This subgroup was only analyzed for water heaters. It comprises 3.5 percent of the sample used for gas-fired storage water heaters, and 11.9 percent of the sample used for electric storage water heaters.

11.3 INPUTS TO THE LIFE-CYCLE COST AND PAYBACK PERIOD

SUBGROUP ANALYSIS

DOE performed the consumer subgroup analysis by analyzing the LCC and PBP of senior-only, low-income, multi-family, or mobile households with the spreadsheet models used for the LCC and PBP analysis.

Tables 11.3.1 and 11.3.2 summarize the household populations for water heaters and direct heating equipment, while Tables 11.3.3 and 11.3.4 summarize the weighted-average annual energy

11-2

### use, and energy prices for the households analyzed in the consumer subgroup analyses. 

### These values are compared against the weighted-average values for the national sample.

For water heaters, DOE performed subgroup analyses for gas-fired storage water heaters and electric storage water heaters. Oil-fired storage water heaters were excluded due to low product shipments. Gas-fired instantaneous water heaters were excluded due to insufficient data.

For direct heating equipment, DOE performed subgroup analyses for gas wall gravity DHE and gas fan wall DHE. Gas floor DHE were excluded due to the low and decreasing levels of product shipments. Gas room DHE were excluded for this same reason. For gas hearth DHE, DOE performed the senior-only analysis but did not perform the low-income analysis due to the extremely small sample size, and relatively high product cost.



### Table 11.3.1 Household Population Data for Water Heaters

Gas Electric

Count Weight Count Weight

National 2,166 55,180,081 1,523 39,506,510

Seniors 317 9,082,147 256 6,900,727

Senior % 14.6% 16.5% 16.8% 17.5%

Low Income 311 6,336,149 291 6,294,691

Low % 14.4% 11.5% 19.1% 15.9%

Multi 241 6,140,241 187 4,797,185

Multi % 11.1% 11.1% 12.3% 12.1%

Mobile 90 1,948,744 181 4,719,689

Mobile % 4.2% 3.5% 11.9% 11.9%

Table 11.3.2 Household Population Data for Direct Heating Equipment

Gas Wall Fan / Gas Wall Gravity Gas Floor Gas Room Gas Hearth

Count Weight (million) Count Weight (million) Count Weight Count Weight

National 101 2.45 95 2.30 153 3.83 121 3.10

Seniors 14 0.46 13 0.40 38 0.94 15 0.40

Low

Income 30 0.69 29 0.67 36 0.85 4 0.08

11-3

### Table 11.3.3 Gas-Fired Water Heaters: Comparison of Input Values for All Households, Senior-Only, Low-Income, Multi-Family, and Mobile Homes

Gas-Fired Water Heaters All

Households Senior -Only LowIncome MultiFamily Mobile

Weighted-Average Annual Energy Use for Baseline Water Heaters Natural Gas Use (MMBtu) 16.7 13.5 16.7 11.97 15.96 Electricity Use (kWh) 0 0 0 0 0 Weighted-Average Natural Gas Prices Average Natural Gas Price ($/MMBtu) 14.17 14.29 14.04 14.38 13.68 Average LPG Price ($/MMBtu) 26.21 25.63 26.97 23.14 26.89 Weighted-Average Electricity Prices Average Electricity Price (¢/kWh) 12 12 12 13 11

Table 11.3.4 Electric Water Heaters: Comparison of Input Values for All Households, Senior-Only, Low-Income, Multi-Family, and Mobile Homes

Electric Water Heaters All

Households SeniorOnly LowIncome MultiFamily Mobile

Weighted-Average Annual Energy Use for Baseline Water Heaters Electricity Use (kWh) 2617 2207 2587 1416 2595 Weighted-Average Electricity Prices Average Electricity Price (¢/kWh) 11 11 11 11 10

Table 11.3.5 Gas Wall Fan DHE: Comparison of Input Values for All Households, Senior-Only, and Low-Income

Gas Wall Fan DHE All Households Senior-Only Low-Income Weighted-Average Annual Energy Use for Baseline DHE Space-Heating Natural Gas Use (MMBtu) 29.6 33.3 42.3 Space-Heating Electricity Use (kWh) 39 44 55 Weighted-Average Natural Gas Prices Average Natural Gas Price ($/MMBtu) 12.25 12.48 12.32 Average LPG Price ($/MMBtu) 26.68 26.48 27.57 Weighted-Average Electricity Prices Average Electricity Price (¢/kWh) 13 11 11

11-4

### Table 11.3.6 Gas Wall Gravity DHE: Comparison of Input Values for All Households, Senior-Only, and Low-Income Gas Wall Gravity DHE All Households Senior-Only Low-Income Weighted-Average Annual Energy Use for Baseline DHE Space-Heating Natural Gas Use (MMBtu) 29.7 33.3 42.3 Space-Heating Electricity Use (kWh) 0 0 0 Weighted-Average Natural Gas Prices Average Natural Gas Price ($/MMBtu) 12.25 12.48 12.32 Average LPG Price ($/MMBtu) 26.70 26.48 27.57 Weighted-Average Electricity Prices Average Electricity Price (¢/kWh) 13 11 11

11.4 RESULTS

11.4.1 Water Heaters

Tables 11.4.1 through 11.4.8 below summarize the LCC results for gas-fired storage water heaters and electric storage water heaters. The LCC results provide the average installed price, average lifetime operating cost (discounted), average life-cycle cost, average life-cycle cost savings, the percentage of consumers that are burdened with net costs, realize net savings, or are not impacted, and the median and average payback period.



### Table 11.4.1	 Gas-Fired Storage Water Heaters: LCC and PBP Results for Senior-Only

Households

EF Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost No Impact* Net

Benefit

0.59 $1,006 $2,022 $3,027

0.62 $1,040 $1,897 $2,938 $73 9% 19% 72% 1.4 4.9

0.63 $1,099 $1,835 $2,935 $74 14% 15% 70% 2.7 11.6

0.64 $1,437 $1,843 $3,280 -$239 71% 10% 20% 36.8 52.4

0.65 $1,465 $1,789 $3,254 -$214 70% 8% 22% 29.3 39.5

0.67 $1,519 $1,679 $3,198 -$161 68% 5% 26% 21.1 24.0

0.80 $1,746 $1,405 $3,151 -$115 66% 1% 32% 15.6 15.3

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback period. In these cases, median is probably a better indicator.

11-5

### Table 11.4.2 Gas-Fired Storage Water Heaters: LCC and PBP Results for Low-Income

Households

EF Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost No Impact* Net

Benefit

0.59 $989 $2,615 $3,604

0.62 $1,033 $2,490 $3,523 $68 12% 19% 70% 1.5 5.8

0.63 $1,103 $2,431 $3,535 $57 19% 15% 66% 2.8 14.0

0.64 $1,430 $2,433 $3,863 -$240 70% 9% 20% 38.1 52.9

0.65 $1,463 $2,376 $3,839 -$218 69% 7% 23% 30.5 41.0

0.67 $1,527 $2,258 $3,784 -$165 68% 5% 27% 22.3 25.6

0.80 $1,748 $1,919 $3,667 -$50 62% 1% 36% 14.8 14.9

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.



### Table 11.4.3	 Gas-Fired Storage Water Heaters: LCC and PBP Results for Multi-Family

Households

EF Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost No Impact* Net

Benefit

0.59 $1,040 $1,650 $2,690

0.62 $1,095 $1,547 $2,642 $40 18% 20% 62% 1.7 9.6

0.63 $1,183 $1,493 $2,676 $10 27% 16% 57% 3.2 19.4

0.64 $1,477 $1,510 $2,987 -$270 72% 10% 18% 41.7 60.1

0.65 $1,517 $1,460 $2,977 -$261 72% 8% 21% 33.5 46.6

0.67 $1,594 $1,351 $2,945 -$231 71% 6% 23% 23.7 27.9

0.80 $1,806 $1,146 $2,952 -$237 72% 2% 26% 18.2 18.2

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.

11-6

### Table 11.4.4 Gas-Fired Storage Water Heaters: LCC and PBP Results for Mobile

Home Households

EF Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost No Impact* Net

Benefit

0.59 $976 $3,151 $4,127

0.62 $1,064 $2,996 $4,060 $58 23% 17% 60% 1.8 10.6

0.63 $1,158 $2,924 $4,082 $38 35% 13% 52% 5.7 17.6

0.64 $1,372 $2,908 $4,280 -$143 65% 9% 26% 27.6 43.0

0.65 $1,439 $2,841 $4,280 -$143 64% 8% 28% 24.4 35.9

0.67 $1,537 $2,669 $4,206 -$72 60% 5% 35% 18.4 23.6

0.80 $1,750 $2,281 $4,031 $100 53% 2% 46% 11.8 13.6

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.



### Table 11.4.5	 Electric Storage Water Heaters: LCC and PBP Results for Senior-Only

Households

EF Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost No Impact* Net

Benefit

0.90 $517 $2,463 $2,979

0.91 $543 $2,424 $2,967 $7 6% 60% 34% 2.7 8.0

0.92 $562 $2,389 $2,951 $16 10% 31% 60% 2.7 7.7

0.93 $571 $2,370 $2,942 $23 11% 28% 61% 2.9 7.8

0.94 $615 $2,317 $2,932 $31 20% 14% 66% 4.3 8.6

0.95 $643 $2,281 $2,924 $38 24% 10% 66% 5.3 8.8

2.0 $1,426 $1,506 $2,932 $30 52% 5% 43% 9.8 24.2

2.2 $1,507 $1,386 $2,894 $68 52% 1% 48% 9.6 20.4

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.

11-7

### Table 11.4.6 Electric Storage Water Heaters: LCC and PBP Results for Low-Income

Households

EF Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost No Impact* Net

Benefit

0.90 $499 $2,802 $3,302

0.91 $532 $2,768 $3,299 $1 8% 57% 34% 2.8 10.4

0.92 $551 $2,736 $3,287 $9 12% 29% 59% 2.9 9.2

0.93 $559 $2,720 $3,279 $14 13% 27% 60% 3.0 9.2

0.94 $610 $2,671 $3,281 $12 25% 14% 62% 5.0 10.2

0.95 $636 $2,640 $3,276 $17 29% 10% 61% 6.3 10.2

2.0 $1,450 $1,690 $3,140 $143 49% 5% 46% 9.3 33.8

2.2 $1,531 $1,566 $3,098 $185 49% 1% 50% 9.2 26.7

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.



### Table 11.4.7	 Electric Storage Water Heaters: LCC and PBP Results for Multi-Family

Households

EF Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost No Impact* Net

Benefit

0.90 $482 $1,607 $2,089

0.91 $521 $1,571 $2,092 -$2 11% 50% 39% 2.8 11.3

0.92 $541 $1,545 $2,086 $1 16% 26% 59% 2.9 10.7

0.93 $547 $1,533 $2,080 $5 17% 24% 59% 2.9 10.7

0.94 $608 $1,485 $2,092 -$6 32% 12% 56% 5.3 12.0

0.95 $629 $1,460 $2,089 -$2 35% 10% 55% 6.8 11.5

2.0 $1,417 $1,047 $2,464 -$359 76% 5% 19% 23.8 69.4

2.2 $1,497 $964 $2,461 -$357 77% 1% 22% 23.2 54.3

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.

11-8

### Table 11.4.8 Electric Storage Water Heaters: LCC and PBP Results for Mobile Home

Households

EF Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost No Impact* Net

Benefit

0.90 $484 $2,721 $3,206

0.91 $516 $2,689 $3,205 $0 9% 53% 38% 2.8 10.6

0.92 $538 $2,663 $3,201 $3 13% 27% 59% 3.0 10.4

0.93 $544 $2,651 $3,195 $6 14% 25% 60% 3.1 10.3

0.94 $602 $2,605 $3,208 -$4 29% 13% 58% 5.6 12.1

0.95 $626 $2,579 $3,205 -$2 34% 10% 56% 7.0 11.7

2.0 $1,469 $1,650 $3,118 $81 51% 5% 44% 9.6 28.1

2.2 $1,549 $1,534 $3,083 $116 52% 1% 47% 9.5 25.6

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.



### 11.4.2 Direct Heating Equipment

Tables 11.4.9 through 11.4.12 below summarize the LCC results for gas wall fan DHE and gas wall gravity DHE. The LCC results provide the average installed price, average lifetime operating cost (discounted), average life-cycle cost, average life-cycle savings, the percentage of consumers that are burdened with net costs, realize net savings, or are not impacted, and the median and average payback period.



### Table 11.4.9 Gas Wall Fan DHE: LCC and PBP Results for Senior-Only Households

AFUE

(%) Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operatin g Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost Net

Benefit No Impact*

74 $1,752 $6,399 $8,150

75 $1,805 $6,100 $7,905 $103 3% 39% 59% 3.0 2.8

76 $1,829 $6,025 $7,854 $126 4% 42% 54% 3.6 8.0

77 $1,871 $5,952 $7,824 $152 22% 64% 13% 5.2 14.0

80 $1,997 $5,754 $7,751 $221 31% 64% 4% 7.2 19.0

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.

11-9

### Table 11.4.10 Gas Wall Fan DHE: LCC and PBP Results for Low-Income Households

AFUE

(%) Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost Net

Benefit No Impact*

74 $1,752 $7,672 $9,424

75 $1,805 $7,411 $9,217 $86 0% 41% 59% 3.3 3.2

75 $1,829 $7,319 $9,149 $118 1% 45% 54% 3.6 3.7

77 $1,872 $7,230 $9,102 $159 17% 70% 13% 5.1 9.0

80 $1,998 $6,989 $8,987 $268 28% 68% 4% 7.0 12.1

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.



### Table 11.4.11 Gas Wall Gravity DHE: LCC and PBP Results for Senior-Only Households

AFUE

(%) Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost Net

Benefit No Impact*

64 $1,371 $6,349 $7,720

66 $1,428 $6,178 $7,606 $35 9% 22% 70% 5.1 13.1

68 $1,464 $6,017 $7,481 $109 14% 46% 41% 4.0 9.0

71 $1,540 $5,792 $7,332 $257 27% 73% 0% 4.8 10.6

72 $1,814 $5,567 $7,381 $209 42% 58% 0% 9.2 26.3

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.

11-10

### Table 11.4.12 Gas Wall Gravity DHE: LCC and PBP Results for Low-Income Households

AFUE

(%) Life-Cycle Cost (2008$) Life-Cycle Cost Savings Payback Period (years)**

Average

Installed

Price Average Operating

Cost Average

LCC Average Savings (2008$) Households with

Median Average Net

Cost Net

Benefit No Impact*

64 $1,371 $7,608 $8,979

66 $1,428 $7,398 $8,826 $47 7% 24% 70% 4.3 8.1

68 $1,465 $7,200 $8,665 $143 11% 49% 40% 3.5 6.1

71 $1,540 $6,924 $8,465 $343 22% 78% 0% 4.1 7.6

72 $1,822 $6,755 $8,577 $231 43% 57% 0% 10.2 11.1

* “No impact” means that the base case product assigned to the household has greater efficiency than the level indicated, so the household is not affected. ** Based on the payback calculation, a very small change in operating cost can result in a few extremely large paybacks, which will skew the average payback. In these cases, median is probably a better indicator.



### 11.5 DISCUSSION

For gas-fired storage water heaters, the impacts of the proposed standard (0.63 EF) are roughly the same for the senior-only sample and the low-income sample as they are for the full household sample for this product class. For the multi-family sample and the mobile home sample, the average LCC savings are somewhat lower than they are for the full household sample, and the fraction of households experiencing a cost (negative savings) is higher. In both cases, however, the average LCC savings is positive, and more than half of the households would experience an LCC benefit.

Because the impacts of standards on the subgroups are of particular interest for electric storage water heaters, DOE compares the impacts among the subgroups with the impacts on all consumers for two considered standard levels (0.95 EF and 2.0 EF) in Figures 11.5.2 through 11.5.4.

T 

### he impacts of the proposed standard (0.95 EF) are roughly the same for the senior-only sample as they are for the full household sample for this product class. The impacts are slightly less positive for the low-income sample, and they are much less positive for the multi-family sample and the mobile home sample. The average LCC savings are -$2 for the latter two subgroups, but in both cases more than half of the households would experience an LCC benefit (refer back to Tables 11.4.7 and 11.4.8).

In the case of a standard at 2.0 EF, the average LCC savings are lower for all of the subgroups than for the full household sample for this product class. The multi-family subgroup would experience an average negative LCC savings of $359 (i.e., the average LCC would increase), and three-fourths of the households would experience a net cost. For the other subgroups, the fraction of households that would experience a net cost is close to or just above50 percent, which is slightly higher than for the full household sample. The impact on the multifamily subgroup is primarily due to the lower hot water use among these households.

11-11-$400 -$300 -$200 -$100 $0 $100 $200 $300

Senior-Only Low-Income Multi-Family Mobile Homes All HouseholdsAverage LCC Savings (2008$)

0.95 EF

2.00 EF



### Figure 11.5.1 Electric Storage Water Heaters: Average LCC Savings by Subgroup

0% 10% 20% 30% 40% 50% 60% 70% 80%

Senior-Only Low-Income Multi-Family Mobile Homes All HouseholdsPercentage of Households with Net Cost (%)

0.95 EF

2.00 EF



### Figure 11.5.2 Electric Storage Water Heaters: Households With Net Cost by Subgroup

11-120 5 10 15 20 25Median Payback Period (years)

0.95 EF

2.00 EF

Senior-Only Low-Income Multi-Family Mobile Homes All Households



### Figure 11.5.3 Electric Storage Water Heaters: Median Payback Period by Subgroup

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### REFERENCES

1. U.S. Department of Energy - Energy Information Administration, Residential Energy Consumption Survey: 2005 Public Use Data Files, 2005.

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

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