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 Room Air Conditioners.......................................................................................... 8-H-1 

8-H.1.2 Clothes Dryers ....................................................................................................... 8-H-3 

LIST OF TABLES 

Table 8-H.1.1 Room Air Conditioners Energy Efficiency: Base Case Market Shares.....8-H-1 

Table 8-H.1.2 Vented Clothes Dryers Energy Efficiency: Base Case Market Shares......8-H-3 

Table 8-H.1.3 Vent-less Clothes Dryers Energy Efficiency: Base Case Market Shares .. 8-H-3 

LIST OF FIGURES 

Figure 8-H.1.1 Energy Star Room Air Conditioner Fraction of Total Room Air 

Conditioner Shipments from 1998 to 2007................................................8-H-2 

Figure 8-H.1.2 Room Air Conditioner Shipment Weighted Efficiency from 1999 to 

2008............................................................................................................8-H-2 


8-H-i 

EERE-2007-BT-STD-0010 COMMENT 20.3
 

 

 

 

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 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, the data on shipmentweighted average efficiency are inconclusive. See the figures 8-H.1.1. and 8-H.1.2., below. 

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

the same as the shares in 2007. The market shares in Table 8-H.1.1 represent the products that 

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

Table 8-H.1.1 Room Air Conditioners Energy Efficiency: Base Case Market Shares 

Less than 6,000 Btu/h 

with Louvers 

8,000–13,999 Btu/h 

with Louvers 

20,000 Btu/h or more 

with Louvers 

8,000–13,999 Btu/h 

without Louvers 

IEER Share IEER Share IEER Share IEER Share 

9.52 96.0% 9.7 51.4% 8.47 37.0% 8.4 39.0% 

10.1 0.0% 10.3 1.5% 9.0 6.1% 8.9 0.0% 

10.6 4.0% 10.8 44.3% 9.4 56.2% 9.3 61.0% 

11.1 0.0% 11.3 1.7% 9.8 0.7% 9.8 0.0% 

11.6 0.0% 11.5 1.1% 10.0 0.0% 

12.0 0.0% 

DOE also assembled data for 2002–2007 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-1 

EERE-2007-BT-STD-0010 COMMENT 20.3
0% 

10% 

20% 

30% 

40% 

50% 

60% 

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 

Year 

Energy Star RAC Fraction of Total

RAC Shipments(%) 

Figure 8-H.1.1	 Energy Star Room Air Conditioner Fraction of
 

Total Room Air Conditioner Shipments from 1998 


to 2007 


8.9 

9.1 

9.3 

9.5 

9.7 

9.9 

10.1 

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 

Year 

Shipment-Weighted EER 

Figure 8-H.1.2	 Room Air Conditioner Shipment Weighted
 

Efficiency from 1999 to 2008 


8-H-2 

EERE-2007-BT-STD-0010 COMMENT 20.3
 

8-H.1.2 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.1.2 and 8-H.1.3 represent the products that households would be expected to purchase in 2014 

in the absence of new standards. 

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

Electric, Standard Electric, Compact 

(120V) 

Electric, Compact 

(240V) 

Gas 

IEF 

(lb/kWh) 

Share IEF 

(lb/kWh) 

Share IEF 

(lb/kWh) 

Share IEF 

(lb/kWh) 

Share 

2.96 29.5% 3.00 100% 2.79 38.9% 2.63 26.8% 

3.04 49.9% 3.08 0.0% 2.86 38.9% 2.71 43.4% 

3.10 20.6% 3.15 0.0% 2.96 0.0% 2.80 28.9% 

3.33 0.0% 3.37 0.0% 3.06 22.2% 2.97 0.9% 

3.35 0.0% 3.41 0.0% 3.10 0.0% 2.98 0.0% 

3.40 0.0% 3.53 0.0% 3.19 0.0% 3.02 0.0% 

4.52 0.0% 4.69 0.0% 4.34 0.0% 

Table 8-H.1.3 Vent-less Clothes Dryers Energy Efficiency: Base Case Market Shares
 

Electric, Compact 

(240V) 

Electric, Combination 

Washer/Dryer 

IEF 

(lb/kWh) 

Share IEF 

(lb/kWh) 

Share 

2.29 100% 1.90 100% 

2.31 0.0% 2.15 0.0% 

2.37 0.0% 2.34 0.0% 

2.39 0.0% 2.36 0.0% 

2.59 0.0% 2.42 0.0% 

3.54 0.0% 3.31 0.0% 

8-H-3 

EERE-2007-BT-STD-0010 COMMENT 20.3
REFERENCES
 

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


and Clothes Dryers. 2008
 

8-H-4 

EERE-2007-BT-STD-0010 COMMENT 20.3