8-H-i

APPENDIX 8-H. DETERMINATION OF BASECASE EFFICIENCY 

DISTRIBUTIONS

TABLE OF CONTENTS

8-H.1 PRODUCT ENERGY EFFICIENCY IN THE BASE CASE ............................... 8-H-1

8-H.1.1 Clothes Dryers ....................................................................................................... 8-H-1

8-H.1.2 Room Air Conditioners .......................................................................................... 8-H-2

LIST OF TABLES

Table 8-H.1.1 Vented Clothes Dryers Energy Efficiency: Base Case Market Shares ...... 8-H-1

Table 8-H.1.2 Vent-less Clothes Dryers Energy Efficiency: Base Case Market Shares .. 8-H-2

Table 8-H.1.3 Room Air Conditioners with Louvers: Base Case Market Shares ............. 8-H-2

Table 8-H.1.4 Room Air Conditioners without Louvers: Base Case Market Shares........ 8-H-2
8-H-1

APPENDIX 8-H. DETERIMINATION OF BASECASE EFFICIENCY 

DISTRIBUTIONS

8-H.1 PRODUCT ENERGY EFFICIENCY IN THE BASE CASE

To estimate the percentage of consumers who would be affected by a standard at any of 

the potential efficiency levels, in its life-cycle cost (LCC) analysis the U.S. Department of 

Energy (DOE) considered the projected distribution of efficiencies for products that consumers 

purchase under the base case (the case without new energy efficiency standards). DOE refers to 

this distribution of product energy efficiencies as the base-case efficiency distribution. Using the 

projected distribution of efficiencies for each product class, DOE randomly assigned a product 

efficiency to each sample household and commercial user. If a household is assigned a product 

efficiency that was greater than or equal to the efficiency of the standard level under 

consideration, the LCC calculation would show that this household would not be affected by that 

standard level. The energy efficiency distributions that DOE used in the LCC analysis are 

described below.

8-H.1.1 Clothes Dryers

To develop a base case energy efficiency distribution for clothes dryers, DOE began with 

data that AHAM provided showing the distribution of clothes dryer efficiencies sold by product 

class in 2005–2007.1 Because there is no evidence of change in average efficiency in recent 

years, DOE assumed that the shares remain the same in 2014. The market shares in Tables 8-

H.1.1 and 8-H.1.2 represent the products that households would be expected to purchase in 2014 

in the absence of new standards. 

 

Table 8-H.1.1 Vented Clothes Dryers Energy Efficiency: Base Case Market Shares

Electric, Standard Electric, Compact

(120V)

Electric, Compact 

(240V)

Gas

CEF

(lb/kWh)

Share CEF

(lb/kWh)

Share CEF

(lb/kWh)

Share CEF

(lb/kWh)

Share

3.55 2.6% 3.43 100.0% 3.12 59.4% 3.14 7.9%

3.56 18.9% 3.48 0.0% 3.16 0.0% 3.16 8.2%

3.61 53.5% 3.61 0.0% 3.27 15.6% 3.20 42.9%

3.73 17.9% 3.72 0.0% 3.36 16.7% 3.30 30.9%

3.81 6.1% 3.80 0.0% 3.48 4.2% 3.41 9.3%

4.08 1.0% 4.08 0.0% 3.60 4.2% 3.61 0.9%

5.42 0.0% 5.41 0.0% 4.89 0.0%
8-H-2

Table 8-H.1.2 Vent-less Clothes Dryers Energy Efficiency: Base Case Market Shares

Electric, Compact

(240V)

Electric, Combination 

Washer/Dryer

CEF

(lb/kWh)

Share CEF

(lb/kWh)

Share

2.55 100.0% 2.08 100.0%

2.59 0.0% 2.35 0.0%

2.69 0.0% 2.38 0.0%

2.71 0.0% 2.46 0.0%

2.80 0.0% 2.56 0.0%

4.03 0.0% 3.69 0.0%

8-H.1.2 Room Air Conditioners

 To develop a base-case energy efficiency distribution for room air conditioners, DOE 

began with data that AHAM provided showing the distribution of room air conditioner 

efficiencies sold by product class in 2005–2007.1 Using these data, DOE derived the shares in 

Table 8-H.1.1. Regarding change in energy efficiency in coming years, DOE used historical 

trends from 2005 to 2009, which give a 0.25 percent annual growth trend in energy star levels. 

Therefore, DOE assumed that the market shares of the efficiency levels in 2014 will be higher 

than in 2007. The market shares in Tables 8-H.1.3 and 8-H.1.4 represent the products that 

consumers would be expected to purchase in 2014 in the absence of new standards. 

Table 8-H.1.3 Room Air Conditioners with Louvers: Base Case Market Shares

Less than 6,000 Btu/h 8,000–13,999 Btu/h 20,000-24,999 Btu/h Greater than 25,000 Btu/h

CEER Share CEER Share CEER Share CEER Share

9.5 70.0% 9.7 38.4% 8.5 13.6% 8.5 12.9%

10.1 0.0% 10.2 2.4% 9.0 1.4% 9.0 2.1%

10.6 29.0% 10.7 57.9% 9.4 81.0% 9.4 85.0%

11.1 1.0% 10.9 1.5% 9.8 2.0% 9.8 0.0%

11.4 0.0% 11.5 0.2% 10.2 2.0%

11.7 0.0% 12.0 0.4%

 

Table 8-H.1.4 Room Air Conditioners without Louvers: Base Case Market Shares

8,000-10,999 Btu/h Greater than 11,000 Btu/h

CEER Share CEER Share

8.4 10.0% 8.4 10.0%

9.3 65.2% 9.3 60.0%

9.6 19.2% 9.5 12.9%

10.0 3.7% 9.8 17.1%

10.4 1.9% 10.0 0.0%
8-H-3

 DOE also assembled data for 2002–2009 on market shares of ENERGY STAR room air 

conditioners by State and organized them into Census Divisions and four large States. In 

assigning a product efficiency to each sample household and commercial user, DOE accounted 

for regional patterns in the efficiency distribution. 
8-H-4

REFERENCES

1. Association of Home Appliance Manufacturers, AHAM Data on Room Air Conditioners 

and Clothes Dryers. 2008