2001 Housing Characteristics Tables

Air Conditioning Tables

(Million U.S. Households; 24 pages, 138 kb)

Contents Pages

HC4-1a. Air Conditioning by Climate Zone, Million U.S. Households, 2001 2 

HC4-2a. Air Conditioning by Year of Construction, Million U.S. Households, 2001 2 

HC4-3a. Air Conditioning by Household Income, Million U.S. Households, 2001 2 

HC4-4a. Air Conditioning by Type of Housing Unit, Million U.S. Households, 2001 2 

HC4-5a. Air Conditioning by Type of Owner-Occupied Housing Unit, Million U.S. Households, 2001 2 

HC4-6a. Air Conditioning by Type of Rented Housing Unit, Million U.S. Households, 2001 2 

HC4-7a. Air Conditioning by Four Most Populated States, Million U.S. Households, 2001 2 

HC4-8a. Air Conditioning by Urban/Rural Location, Million U.S. Households, 2001 2 

HC4-9a. Air Conditioning by Northeast Census Region, Million U.S. Households, 2001 2 

HC4-10a. Air Conditioning by Midwest Census Region, Million U.S. Households, 2001 2 

HC4-11a. Air Conditioning by South Census Region, Million U.S. Households, 2001 2 

HC4-12a. Air Conditioning by West Census Region, Million U.S. Households, 2001 2

These data are from the 2001 Residential Energy Consumption Survey (RECS) which provides information on the use of

energy in residential housing units in the United States. The RECS is a national statistical survey that collects energy-related

data for occupied primary housing units. RECS was first conducted in 1978; the eleventh and most recent survey was

conducted in 2001. In the 2001 RECS, data were collected from a sample of 4,822 households in housing units statistically

selected to represent the 107.0 million housing units in the United States. The RECS data are available for the four Census

regions, the nine Census divisions,and for the four most populous States--California, Florida, New York, and Texas.

Data provided here are in the public domain and may be reproduced without permission. Appropriate credit would be

appreciated. A suggested citation is “U.S. Department of Energy, Energy Information Administration, 2001 Residential 

Energy Consumption Survey."

Electronic Products and Services

Users can view and download selected pages or entire reports, search for information, download data and analysis

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Contact: Stephanie J. Battles, Survey Manager (stephanie.battles@eia.doe.gov)

World Wide Web: http://www.eia.doe.gov/emeu/consumption 
Table HC4-1a. Air Conditioning by Climate Zone, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

Climate Zone1

RSE

Row

Factors

Fewer than 2,000 CDD and --

2,000 CDD

or More

and Fewer

than

4,000 HDD

More than

7,000 HDD

5,500 to

7,000 HDD

4,000 to

5,499 HDD

Fewer than

4,000 HDD

0.4 2.1 1.0 0.9 1.5 1.0

Total Households With

Air-Conditioning ........................... 82.9 5.4 20.9 20.2 14.2 22.1 8.1

 Air Conditioners Not Used ............ 2.1 Q 0.4 0.3 0.8 0.4 23.2

Households Using Electric

Air-Conditioning2 .......................... 80.8 5.3 20.5 19.9 13.4 21.8 8.2

Type of Electric Air-Conditioning

Used

 Central Air-Conditioning3 .............. 57.5 3.1 12.9 12.7 10.5 18.2 9.2

 Without a Heat Pump .................. 46.2 3.0 12.1 9.8 7.0 14.3 10.7

 With a Heat Pump ....................... 11.3 Q 0.9 2.9 3.5 3.9 19.5

 Room Air-Conditioning .................. 23.3 2.2 7.6 7.2 2.9 3.6 11.3

 1 Unit .......................................... 12.8 1.4 4.5 3.4 1.9 1.5 13.5

 2 Units ......................................... 7.5 0.5 2.2 2.5 0.8 1.4 13.8

 3 or More Units ........................... 3.0 0.2 0.8 1.2 0.2 0.7 20.1

Number of Rooms AirConditioned in Summer 2001

 One or Two ................................... 12.3 0.8 4.4 3.6 1.8 1.8 12.1

 Three ............................................ 9.2 0.9 2.2 2.2 1.6 2.4 16.5

 Four ............................................. 12.0 0.8 2.6 3.1 1.7 3.8 14.4

 Five or More .................................. 47.3 2.8 11.3 11.0 8.4 13.8 9.6

Percentage of Rooms

Air-Conditioned

 100% ............................................. 58.8 3.3 13.5 13.7 10.3 18.0 9.4

 50% to 99% .................................. 12.1 1.1 3.2 3.2 1.7 2.8 13.0

 25% to 49% .................................. 6.4 0.5 2.3 2.1 0.8 0.7 15.0

 1% to 24% .................................... 3.5 0.3 1.5 0.8 0.5 0.3 18.9

Large Tree(s) that

Shade the Home

 Yes ................................................ 41.5 2.6 10.0 9.5 6.9 12.5 10.5

 No ................................................. 39.3 2.6 10.5 10.4 6.4 9.3 10.1

Central Air-Conditioner Age

(excludes systems for more than

one housing unit)

 Less than 2 Years ......................... 6.1 0.4 1.1 1.4 1.2 1.9 17.0

 2 to 4 Years .................................. 10.1 0.5 2.6 2.2 2.0 2.9 15.5

 5 to 9 Years .................................. 15.4 0.9 3.2 3.3 3.0 5.0 13.1

 10 to 19 Years .............................. 15.0 0.8 3.7 3.1 2.8 4.6 14.1

 20 Years or More .......................... 5.7 0.5 1.4 1.1 1.0 1.7 17.9

 Don’t Know ................................... 3.7 Q 0.6 1.0 0.4 1.7 23.3

Central Air-Conditioning Use

 Only a Few Times ......................... 16.8 1.8 5.9 4.2 2.9 1.9 12.5

 Quite a Bit ..................................... 12.1 0.5 3.4 3.2 1.6 3.4 13.6

 All Summer ................................... 28.4 0.7 3.6 5.3 6.0 12.8 12.2

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-1a. Air Conditioning by Climate Zone, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

Climate Zone1

RSE

Row

Factors

Fewer than 2,000 CDD and --

2,000 CDD

or More

and Fewer

than

4,000 HDD

More than

7,000 HDD

5,500 to

7,000 HDD

4,000 to

5,499 HDD

Fewer than

4,000 HDD

0.4 2.1 1.0 0.9 1.5 1.0

Pays for Electricity for Central

Air-Conditioning

 Yes ................................................ 55.5 3.1 12.5 12.1 10.3 17.4 9.4

 No ................................................. 2.0 Q 0.4 0.6 Q 0.8 30.6

Age of Most-Used Room Air

Conditioner

 Less than 2 Years ......................... 3.1 0.3 1.1 0.9 0.4 0.4 21.1

 2 to 4 Years .................................. 5.3 0.3 1.5 2.0 0.5 1.0 15.4

 5 to 9 Years .................................. 6.4 0.7 1.8 1.9 0.8 1.2 15.4

 10 or 19 Years .............................. 4.3 0.5 1.5 1.2 0.5 0.5 19.1

 20 or More Years .......................... 2.0 0.2 0.7 0.6 Q 0.3 28.5

 Don’t Know ................................... 2.2 0.2 0.9 0.5 0.4 Q 25.9

Room Air-Conditioning Use

 Only a Few Times ......................... 13.6 1.4 5.3 4.0 1.4 1.4 12.4

 Quite a Bit ..................................... 5.0 0.5 1.3 1.7 0.7 0.8 19.9

 All Summer ................................... 4.7 0.2 1.0 1.4 0.8 1.3 21.0

Pays for Electricity for Room

Air-Conditioning

 Yes ................................................ 21.9 2.1 7.1 6.7 2.7 3.3 11.4

 No ................................................. 1.5 Q 0.5 0.5 Q Q 40.3

1 One of five climatically distinct areas, determined according to the 30-year average (1961-1990) of the annual heating and cooling degree-days. For this

report, the heating or cooling degree-days are a measure of how cold or how hot a location is over a period of one year, relative to a base temperature of 65

degrees Fahrenheit. A household is assigned to a climate zone according to the 30-year average annual degree-days for an appropriate nearby weather station. 2 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does

include the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated

as if the fuel was electricity. 3 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million

households using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals.

 • See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-2a. Air Conditioning by Year of Construction, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

Year of Construction

RSE

Row

Factors

1990

 to

20011

1980

to

1989

1970

to

1979

1960

to

1969

1950

to

1959

1949

or

Before

0.4 1.6 1.2 1.1 1.2 1.1 0.9

Households With Electric

Air-Conditioning Equipment ........ 82.9 13.6 16.0 14.7 10.4 10.5 17.6 4.7

 Air Conditioners Not Used ............ 2.1 Q 0.3 0.5 0.3 0.4 0.5 27.2

Households Using Electric

Air-Conditioning2 .......................... 80.8 13.4 15.8 14.2 10.1 10.2 17.1 4.7

Type of Electric Air-Conditioning

Used

 Central Air-Conditioning3 .............. 57.5 12.6 13.7 11.0 7.1 6.6 6.4 5.9

 Without a Heat Pump .................. 46.2 10.1 10.4 8.0 6.1 5.9 5.7 7.0

 With a Heat Pump ....................... 11.3 2.5 3.3 3.0 1.0 0.8 0.6 15.2

 Room Air-Conditioning .................. 23.3 0.8 2.1 3.1 3.1 3.5 10.8 8.7

 1 Unit .......................................... 12.8 0.5 1.2 2.0 1.7 1.7 5.7 11.4

 2 Units ......................................... 7.5 0.2 0.8 1.0 0.8 1.3 3.3 13.8

 3 or More Units ........................... 3.0 Q Q 0.2 0.5 0.5 1.7 20.9

Number of Rooms AirConditioned in Summer 2001

 One or Two ................................... 12.3 0.4 1.4 2.1 1.5 1.7 5.2 11.6

 Three ............................................ 9.2 0.8 1.7 1.9 1.7 0.9 2.2 14.3

 Four ............................................. 12.0 1.7 2.9 2.4 1.1 1.3 2.6 11.2

 Five or More .................................. 47.3 10.4 9.8 7.9 5.9 6.2 7.1 6.5

Percentage of Rooms

Air-Conditioned

 100% ............................................. 58.8 11.5 13.3 11.0 7.4 6.7 8.9 5.6

 50% to 99% .................................. 12.1 1.6 1.6 2.1 1.6 1.9 3.2 11.3

 25% to 49% .................................. 6.4 Q 0.7 0.7 0.8 0.9 3.1 14.6

 1% to 24% .................................... 3.5 Q 0.2 0.3 0.3 0.6 1.9 20.0

Large Tree(s) that

Shade the Home

 Yes ................................................ 41.5 4.6 7.5 8.2 6.2 6.0 9.1 6.5

 No ................................................. 39.3 8.8 8.3 6.0 4.0 4.1 8.1 6.9

Central Air-Conditioner Age

(excludes systems for more than

one housing unit)

 Less than 2 Years ......................... 6.1 1.7 1.2 1.1 0.8 0.7 0.6 15.8

 2 to 4 Years .................................. 10.1 3.5 1.3 1.7 1.2 1.2 1.3 13.5

 5 to 9 Years .................................. 15.4 6.0 1.8 2.3 1.8 1.7 1.8 11.1

 10 to 19 Years .............................. 15.0 1.3 7.3 1.9 1.7 1.5 1.4 11.4

 20 Years or More .......................... 5.7 Q 0.8 2.5 0.9 0.8 0.6 17.5

 Don’t Know ................................... 3.7 Q 1.0 1.2 0.4 0.6 0.5 19.2

Central Air-Conditioning Use

 Only a Few Times ......................... 16.8 3.5 3.5 3.0 2.1 2.5 2.2 10.0

 Quite a Bit ..................................... 12.1 2.8 2.7 2.2 1.6 1.4 1.5 11.4

 All Summer ................................... 28.4 6.3 7.5 5.8 3.3 2.8 2.7 8.3

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-2a. Air Conditioning by Year of Construction, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

Year of Construction

RSE

Row

Factors

1990

 to

20011

1980

to

1989

1970

to

1979

1960

to

1969

1950

to

1959

1949

or

Before

0.4 1.6 1.2 1.1 1.2 1.1 0.9

Pays for Electricity for Central

Air-Conditioning

 Yes ................................................ 55.5 12.5 13.2 10.5 6.8 6.4 6.2 6.1

 No ................................................. 2.0 Q 0.5 0.6 0.3 Q Q 26.3

Age of Most-Used Room Air

Conditioner

 Less than 2 Years ......................... 3.1 0.2 0.2 0.4 0.3 0.5 1.5 22.3

 2 to 4 Years .................................. 5.3 Q 0.4 0.6 0.6 0.9 2.6 15.2

 5 to 9 Years .................................. 6.4 0.3 0.5 0.7 0.9 1.0 3.0 16.5

 10 or 19 Years .............................. 4.3 Q 0.5 0.5 0.5 0.7 2.0 17.8

 20 or More Years .......................... 2.0 Q Q 0.4 0.4 0.3 0.7 24.7

 Don’t Know ................................... 2.2 Q 0.3 0.5 0.4 Q 0.8 24.2

Room Air-Conditioning Use

 Only a Few Times ......................... 13.6 0.4 1.2 1.7 1.7 2.3 6.3 10.7

 Quite a Bit ..................................... 5.0 Q 0.4 0.7 0.7 0.6 2.4 18.0

 All Summer ................................... 4.7 0.2 0.4 0.7 0.7 0.7 2.1 19.3

Pays for Electricity for Room

Air-Conditioning

 Yes ................................................ 21.9 0.8 1.9 2.8 2.8 3.2 10.4 8.8

 No ................................................. 1.5 Q Q 0.3 0.3 0.3 0.4 30.1

1 New construction for 2001 includes only those housing units built and occupied between January and the April-August period when the household interviews were

conducted. 2 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does include the

small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as if the fuel was

electricity. 3 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million households

using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. • See

"Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-3a. Air Conditioning by Household Income, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

2001 Household Income

Below Poverty

Line

Eligible

for

Federal

Assistance1

RSE

Row

Factors

Less

than

$14,999

$15,000

to

$29,999

$30,000

to

$49,999

$50,000

or

More

0.5 1.4 1.1 1.0 0.9 1.5 0.9

Households With Electric

Air-Conditioning Equipment ........ 82.9 12.3 17.4 21.5 31.7 9.6 23.4 3.9

 Air Conditioners Not Used ............ 2.1 0.4 0.7 0.5 0.5 0.4 0.9 20.8

Households Using Electric

Air-Conditioning2 .......................... 80.8 11.9 16.7 21.0 31.2 9.1 22.6 3.9

Type of Electric Air-Conditioning

Used

 Central Air-Conditioning3 .............. 57.5 6.2 10.7 15.2 25.3 4.5 12.4 5.3

 Without a Heat Pump .................. 46.2 4.9 9.1 12.1 20.1 3.6 10.4 6.1

 With a Heat Pump ....................... 11.3 1.3 1.6 3.2 5.2 0.8 2.0 17.0

 Room Air-Conditioning .................. 23.3 5.7 6.0 5.8 5.9 4.7 10.1 6.1

 1 Unit .......................................... 12.8 4.0 3.4 2.9 2.5 3.3 6.3 8.1

 2 Units ......................................... 7.5 1.4 1.9 2.2 2.0 1.1 3.1 10.2

 3 or More Units ........................... 3.0 0.3 0.7 0.7 1.3 0.3 0.8 20.0

Number of Rooms AirConditioned in Summer 2001

 One or Two ................................... 12.3 3.1 3.4 2.7 3.1 2.4 5.4 8.2

 Three ............................................ 9.2 2.7 2.7 2.1 1.7 1.9 4.1 11.4

 Four ............................................. 12.0 2.4 2.8 4.3 2.5 1.6 3.8 9.4

 Five or More .................................. 47.3 3.7 7.9 11.9 23.8 3.2 9.3 5.7

Percentage of Rooms

Air-Conditioned

 100% ............................................. 58.8 8.0 11.6 15.0 24.2 6.2 15.2 4.8

 50% to 99% .................................. 12.1 1.7 3.0 3.5 3.8 1.3 3.5 8.9

 25% to 49% .................................. 6.4 1.5 1.4 1.7 1.8 1.2 2.7 10.6

 1% to 24% .................................... 3.5 0.6 0.7 0.9 1.3 0.5 1.2 16.1

Large Tree(s) that

Shade the Home

 Yes ................................................ 41.5 5.0 8.5 11.2 16.8 3.9 10.4 5.9

 No ................................................. 39.3 6.9 8.2 9.8 14.3 5.2 12.2 5.5

Central Air-Conditioner Age

(excludes systems for more than

one housing unit)

 Less than 2 Years ......................... 6.1 0.7 1.1 1.0 3.2 0.7 1.3 13.7

 2 to 4 Years .................................. 10.1 1.0 2.0 2.6 4.6 0.7 2.2 11.2

 5 to 9 Years .................................. 15.4 1.2 2.5 3.9 7.8 0.9 2.9 10.4

 10 to 19 Years .............................. 15.0 1.5 2.3 4.5 6.8 0.8 2.7 11.7

 20 Years or More .......................... 5.7 0.8 1.4 1.5 2.0 0.6 1.5 15.0

 Don’t Know ................................... 3.7 0.5 1.3 1.2 0.8 0.3 1.3 16.7

Central Air-Conditioning Use

 Only a Few Times ......................... 16.8 1.7 3.6 4.5 6.8 1.2 3.8 9.1

 Quite a Bit ..................................... 12.1 1.2 2.1 3.1 5.7 0.7 2.6 10.6

 All Summer ................................... 28.4 3.1 5.0 7.5 12.8 2.5 5.9 8.0

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-3a. Air Conditioning by Household Income, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

2001 Household Income

Below Poverty

Line

Eligible

for

Federal

Assistance1

RSE

Row

Factors

Less

than

$14,999

$15,000

to

$29,999

$30,000

to

$49,999

$50,000

or

More

0.5 1.4 1.1 1.0 0.9 1.5 0.9

Pays for Electricity for Central

Air-Conditioning

 Yes ................................................ 55.5 5.5 10.3 14.6 25.1 4.0 11.5 5.5

 No ................................................. 2.0 0.6 0.5 0.6 Q 0.5 0.9 20.0

Age of Most-Used Room Air

Conditioner

 Less than 2 Years ......................... 3.1 0.7 0.6 0.9 0.8 0.6 1.1 16.0

 2 to 4 Years .................................. 5.3 1.2 1.5 1.2 1.5 0.9 2.5 11.6

 5 to 9 Years .................................. 6.4 1.4 1.5 1.6 1.9 1.1 2.4 12.1

 10 or 19 Years .............................. 4.3 1.0 1.1 1.2 0.9 0.7 1.8 12.5

 20 or More Years .......................... 2.0 0.6 0.6 0.4 0.4 0.6 1.0 19.3

 Don’t Know ................................... 2.2 0.8 0.6 0.5 0.3 0.8 1.3 21.5

Room Air-Conditioning Use

 Only a Few Times ......................... 13.6 3.2 3.5 3.3 3.5 2.6 5.8 7.4

 Quite a Bit ..................................... 5.0 1.0 1.3 1.6 1.1 0.7 1.8 13.6

 All Summer ................................... 4.7 1.5 1.2 0.8 1.2 1.3 2.5 13.4

Pays for Electricity for Room

Air-Conditioning

 Yes ................................................ 21.9 5.0 5.6 5.4 5.8 4.0 9.1 6.1

 No ................................................. 1.5 0.7 0.3 0.3 Q 0.6 1.0 25.3

1 Below 150 percent of poverty line or 60 percent of median State income. 2 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does include the

small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as if the fuel was

electricity. 3 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million households

using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. • See

"Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-4a. Air Conditioning by Type of Housing Unit,

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

Type of Housing Unit

RSE

Row

Factors

Single-Family 

Apartments in Buildings With

Two to Four Units Five or More Units Mobile Home

0.4 0.6 1.5 1.4 1.8

Households With Electric

Air-Conditioning Equipment ........ 82.9 58.7 6.5 12.4 5.3 4.9

 Air Conditioners Not Used ............ 2.1 1.1 Q 0.6 Q 21.8

Households Using Electric

Air-Conditioning1 .......................... 80.8 57.6 6.3 11.8 5.1 4.9

Type of Electric Air-Conditioning

Used

 Central Air-Conditioning2 .............. 57.5 43.6 3.2 7.1 3.5 6.7

 Without a Heat Pump .................. 46.2 35.0 2.4 6.1 2.7 7.7

 With a Heat Pump ....................... 11.3 8.6 0.8 1.0 0.8 19.7

 Room Air-Conditioning .................. 23.3 13.9 3.1 4.7 1.6 7.7

 1 Unit .......................................... 12.8 6.7 1.9 3.3 0.9 9.2

 2 Units ......................................... 7.5 4.9 0.9 1.0 0.7 12.0

 3 or More Units ........................... 3.0 2.3 0.3 0.3 Q 21.8

Number of Rooms AirConditioned in Summer 2001

 One or Two ................................... 12.3 6.3 2.2 3.0 0.8 9.3

 Three ............................................ 9.2 3.7 1.0 3.6 0.8 13.1

 Four ............................................. 12.0 5.8 1.8 3.1 1.3 10.8

 Five or More .................................. 47.3 41.7 1.3 2.0 2.2 8.5

Percentage of Rooms

Air-Conditioned

 100% ............................................. 58.8 42.0 3.9 9.1 3.8 6.3

 50% to 99% .................................. 12.1 8.6 1.1 1.4 0.9 10.3

 25% to 49% .................................. 6.4 4.2 0.9 0.9 0.3 13.0

 1% to 24% .................................... 3.5 2.7 0.4 0.3 Q 16.0

Large Tree(s) that

Shade the Home

 Yes ................................................ 41.5 33.1 2.2 3.6 2.5 7.6

 No ................................................. 39.3 24.4 4.1 8.1 2.6 7.3

Central Air-Conditioner Age

(excludes systems for more than

one housing unit)

 Less than 2 Years ......................... 6.1 5.0 Q 0.4 0.5 16.3

 2 to 4 Years .................................. 10.1 8.7 0.3 0.4 0.8 17.8

 5 to 9 Years .................................. 15.4 12.8 0.4 1.2 1.0 13.0

 10 to 19 Years .............................. 15.0 11.9 0.9 1.4 0.8 13.9

 20 Years or More .......................... 5.7 3.9 0.7 0.9 0.2 16.2

 Don’t Know ................................... 3.7 1.3 0.6 1.7 Q 17.2

Central Air-Conditioning Use

 Only a Few Times ......................... 16.8 12.8 0.9 2.1 0.9 11.3

 Quite a Bit ..................................... 12.1 9.0 0.6 1.7 0.8 12.0

 All Summer ................................... 28.4 21.8 1.7 3.2 1.7 9.6

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-4a. Air Conditioning by Type of Housing Unit,

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

Type of Housing Unit

RSE

Row

Factors

Single-Family 

Apartments in Buildings With

Two to Four Units Five or More Units Mobile Home

0.4 0.6 1.5 1.4 1.8

Pays for Electricity for Central

Air-Conditioning

 Yes ................................................ 55.5 43.2 3.0 5.9 3.4 7.0

 No ................................................. 2.0 0.4 Q 1.2 Q 33.7

Age of Most-Used Room Air

Conditioner

 Less than 2 Years ......................... 3.1 1.7 0.5 0.5 0.3 18.6

 2 to 4 Years .................................. 5.3 2.9 1.0 1.1 0.4 13.4

 5 to 9 Years .................................. 6.4 4.3 0.8 0.9 0.3 14.2

 10 or 19 Years .............................. 4.3 3.1 0.3 0.5 0.4 14.3

 20 or More Years .......................... 2.0 1.3 Q 0.6 Q 25.1

 Don’t Know ................................... 2.2 0.6 0.3 1.1 Q 21.9

Room Air-Conditioning Use

 Only a Few Times ......................... 13.6 7.9 1.9 3.0 0.8 9.6

 Quite a Bit ..................................... 5.0 3.2 0.6 0.9 0.3 16.7

 All Summer ................................... 4.7 2.9 0.6 0.7 0.5 15.1

Pays for Electricity for Room

Air-Conditioning

 Yes ................................................ 21.9 13.7 2.8 3.8 1.6 7.7

 No ................................................. 1.5 Q 0.3 0.9 Q 25.7

1 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It

does include the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were

treated as if the fuel was electricity. 2 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both

central air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3

million households using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to

totals. • See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption

Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-5a. Air Conditioning by Type of Owner-Occupied Housing Unit, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

OwnerOccupied

Units

Type of Owner-Occupied Housing Unit

RSE

Row

Factors

Single-Family 

Apartments in Buildings With

Two to Four Units Five or More Units Mobile Home

0.5 0.5 1.5 1.4 1.8

Households With Electric

Air-Conditioning Equipment ........ 59.5 58.7 6.5 12.4 5.3 5.2

 Air Conditioners Not Used ............ 1.2 1.1 Q 0.6 Q 23.3

Households Using Electric

Air-Conditioning1 .......................... 58.2 57.6 6.3 11.8 5.1 5.3

Type of Electric Air-Conditioning

Used

 Central Air-Conditioning2 .............. 44.7 43.6 3.2 7.1 3.5 7.0

 Without a Heat Pump .................. 35.6 35.0 2.4 6.1 2.7 7.7

 With a Heat Pump ....................... 9.1 8.6 0.8 1.0 0.8 19.9

 Room Air-Conditioning .................. 13.5 13.9 3.1 4.7 1.6 7.9

 1 Unit .......................................... 6.3 6.7 1.9 3.3 0.9 9.3

 2 Units ......................................... 4.8 4.9 0.9 1.0 0.7 12.5

 3 or More Units ........................... 2.4 2.3 0.3 0.3 Q 22.5

Number of Rooms AirConditioned in Summer 2001

 One or Two ................................... 6.1 6.3 2.2 3.0 0.8 9.7

 Three ............................................ 3.9 3.7 1.0 3.6 0.8 13.8

 Four ............................................. 6.7 5.8 1.8 3.1 1.3 11.5

 Five or More .................................. 41.5 41.7 1.3 2.0 2.2 8.7

Percentage of Rooms

Air-Conditioned

 100% ............................................. 43.0 42.0 3.9 9.1 3.8 6.7

 50% to 99% .................................. 8.8 8.6 1.1 1.4 0.9 10.5

 25% to 49% .................................. 3.9 4.2 0.9 0.9 0.3 13.6

 1% to 24% .................................... 2.6 2.7 0.4 0.3 Q 16.2

Large Tree(s) that

Shade the Home

 Yes ................................................ 33.1 33.1 2.2 3.6 2.5 7.9

 No ................................................. 25.1 24.4 4.1 8.1 2.6 7.8

Central Air-Conditioner Age

(excludes systems for more than

one housing unit)

 Less than 2 Years ......................... 5.3 5.0 Q 0.4 0.5 16.2

 2 to 4 Years .................................. 8.5 8.7 0.3 0.4 0.8 18.3

 5 to 9 Years .................................. 13.1 12.8 0.4 1.2 1.0 13.4

 10 to 19 Years .............................. 12.7 11.9 0.9 1.4 0.8 14.0

 20 Years or More .......................... 4.0 3.9 0.7 0.9 0.2 16.5

 Don’t Know ................................... 1.0 1.3 0.6 1.7 Q 19.5

Central Air-Conditioning Use

 Only a Few Times ......................... 13.0 12.8 0.9 2.1 0.9 11.5

 Quite a Bit ..................................... 9.3 9.0 0.6 1.7 0.8 12.3

 All Summer ................................... 22.3 21.8 1.7 3.2 1.7 10.0

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-5a. Air Conditioning by Type of Owner-Occupied Housing Unit, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

OwnerOccupied

Units

Type of Owner-Occupied Housing Unit

RSE

Row

Factors

Single-Family 

Apartments in Buildings With

Two to Four Units Five or More Units Mobile Home

0.5 0.5 1.5 1.4 1.8

Pays for Electricity for Central

Air-Conditioning

 Yes ................................................ 44.5 43.2 3.0 5.9 3.4 7.2

 No ................................................. 0.3 0.4 Q 1.2 Q 45.0

Age of Most-Used Room Air

Conditioner

 Less than 2 Years ......................... 1.6 1.7 0.5 0.5 0.3 19.4

 2 to 4 Years .................................. 3.0 2.9 1.0 1.1 0.4 14.5

 5 to 9 Years .................................. 4.1 4.3 0.8 0.9 0.3 14.9

 10 or 19 Years .............................. 3.1 3.1 0.3 0.5 0.4 15.0

 20 or More Years .......................... 1.3 1.3 Q 0.6 Q 26.3

 Don’t Know ................................... 0.4 0.6 0.3 1.1 Q 25.4

Room Air-Conditioning Use

 Only a Few Times ......................... 8.0 7.9 1.9 3.0 0.8 9.8

 Quite a Bit ..................................... 3.0 3.2 0.6 0.9 0.3 17.2

 All Summer ................................... 2.5 2.9 0.6 0.7 0.5 15.8

Pays for Electricity for Room

Air-Conditioning

 Yes ................................................ 13.4 13.7 2.8 3.8 1.6 8.0

 No ................................................. Q Q 0.3 0.9 Q 20.7

1 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does include

the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as if the fuel

was electricity. 2 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million households

using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. 

• See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-6a. Air Conditioning by Type of Rented Housing Unit, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

Rented

Units

Type of Rented Housing Unit

RSE

Row

Factors

Single-Family 

Apartments in Buildings With

Two to Four Units Five or More Units Mobile Home

0.8 0.5 1.4 1.2 1.6

Households With Electric

Air-Conditioning Equipment ........ 23.4 58.7 6.5 12.4 5.3 6.1

 Air Conditioners Not Used ............ 0.9 1.1 Q 0.6 Q 23.0

Households Using Electric

Air-Conditioning1 .......................... 22.5 57.6 6.3 11.8 5.1 6.2

Type of Electric Air-Conditioning

Used

 Central Air-Conditioning2 .............. 12.7 43.6 3.2 7.1 3.5 8.5

 Without a Heat Pump .................. 10.6 35.0 2.4 6.1 2.7 9.3

 With a Heat Pump ....................... 2.2 8.6 0.8 1.0 0.8 21.7

 Room Air-Conditioning .................. 9.8 13.9 3.1 4.7 1.6 8.8

 1 Unit .......................................... 6.5 6.7 1.9 3.3 0.9 10.5

 2 Units ......................................... 2.7 4.9 0.9 1.0 0.7 13.4

 3 or More Units ........................... 0.6 2.3 0.3 0.3 Q 25.7

Number of Rooms AirConditioned in Summer 2001

 One or Two ................................... 6.1 6.3 2.2 3.0 0.8 10.0

 Three ............................................ 5.3 3.7 1.0 3.6 0.8 14.0

 Four ............................................. 5.3 5.8 1.8 3.1 1.3 12.0

 Five or More .................................. 5.8 41.7 1.3 2.0 2.2 10.9

Percentage of Rooms

Air-Conditioned

 100% ............................................. 15.8 42.0 3.9 9.1 3.8 7.7

 50% to 99% .................................. 3.3 8.6 1.1 1.4 0.9 11.5

 25% to 49% .................................. 2.6 4.2 0.9 0.9 0.3 14.5

 1% to 24% .................................... 0.9 2.7 0.4 0.3 Q 18.4

Large Tree(s) that

Shade the Home

 Yes ................................................ 8.4 33.1 2.2 3.6 2.5 9.3

 No ................................................. 14.2 24.4 4.1 8.1 2.6 8.1

Central Air-Conditioner Age

(excludes systems for more than

one housing unit)

 Less than 2 Years ......................... 0.8 5.0 Q 0.4 0.5 20.1

 2 to 4 Years .................................. 1.6 8.7 0.3 0.4 0.8 21.4

 5 to 9 Years .................................. 2.3 12.8 0.4 1.2 1.0 16.7

 10 to 19 Years .............................. 2.3 11.9 0.9 1.4 0.8 17.0

 20 Years or More .......................... 1.7 3.9 0.7 0.9 0.2 18.5

 Don’t Know ................................... 2.8 1.3 0.6 1.7 Q 17.4

Central Air-Conditioning Use

 Only a Few Times ......................... 3.8 12.8 0.9 2.1 0.9 13.3

 Quite a Bit ..................................... 2.8 9.0 0.6 1.7 0.8 13.8

 All Summer ................................... 6.1 21.8 1.7 3.2 1.7 11.7

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-6a. Air Conditioning by Type of Rented Housing Unit, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

Rented

Units

Type of Rented Housing Unit

RSE

Row

Factors

Single-Family 

Apartments in Buildings With

Two to Four Units Five or More Units Mobile Home

0.8 0.5 1.4 1.2 1.6

Pays for Electricity for Central

Air-Conditioning

 Yes ................................................ 11.0 43.2 3.0 5.9 3.4 9.0

 No ................................................. 1.7 0.4 Q 1.2 Q 31.1

Age of Most-Used Room Air

Conditioner

 Less than 2 Years ......................... 1.5 1.7 0.5 0.5 0.3 20.0

 2 to 4 Years .................................. 2.4 2.9 1.0 1.1 0.4 14.4

 5 to 9 Years .................................. 2.3 4.3 0.8 0.9 0.3 15.9

 10 or 19 Years .............................. 1.1 3.1 0.3 0.5 0.4 16.0

 20 or More Years .......................... 0.8 1.3 Q 0.6 Q 28.4

 Don’t Know ................................... 1.8 0.6 0.3 1.1 Q 22.4

Room Air-Conditioning Use

 Only a Few Times ......................... 5.6 7.9 1.9 3.0 0.8 10.9

 Quite a Bit ..................................... 2.0 3.2 0.6 0.9 0.3 18.0

 All Summer ................................... 2.2 2.9 0.6 0.7 0.5 15.8

Pays for Electricity for Room

Air-Conditioning

 Yes ................................................ 8.5 13.7 2.8 3.8 1.6 8.9

 No ................................................. 1.4 Q 0.3 0.9 Q 23.8

1 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does include

the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as if the fuel

was electricity. 2 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million households

using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. 

• See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-7a. Air Conditioning by Four Most Populated States, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

Four Most Populated States

RSE

Row

Factors

New York California Texas Florida

0.4 1.1 1.7 1.2 1.2

Households With Electric

Air-Conditioning Equipment ...................... 82.9 4.9 6.0 7.4 6.2 2.4

 Air Conditioners Not Used ........................... 2.1 0.1 0.8 Q 0.1 23.2

Households Using Electric

Air-Conditioning1 ........................................ 80.8 4.7 5.2 7.4 6.1 2.6

Type of Electric Air-Conditioning Used

 Central Air-Conditioning2 ............................ 57.5 1.3 3.9 6.2 5.7 6.7

 Without a Heat Pump ................................ 46.2 1.2 3.2 5.5 3.8 8.1

 With a Heat Pump ..................................... 11.3 Q 0.8 0.6 1.9 14.7

 Room Air-Conditioning ................................ 23.3 3.4 1.2 1.2 0.3 13.6

 1 Unit ......................................................... 12.8 1.6 1.0 0.5 Q 11.9

 2 Units ....................................................... 7.5 1.2 0.1 0.4 0.1 17.9

 3 or More Units .......................................... 3.0 0.7 Q Q Q 17.9

Number of Rooms AirConditioned in Summer 2001

 One or Two .................................................. 12.3 2.1 1.0 0.7 0.3 13.9

 Three ........................................................... 9.2 0.8 1.0 1.0 0.3 19.2

 Four ............................................................ 12.0 0.6 0.8 1.0 0.8 12.0

 Five or More ................................................ 47.3 1.2 2.3 4.7 4.6 6.3

Percentage of Rooms

Air-Conditioned

 100% ........................................................... 58.8 1.9 3.5 6.2 5.4 4.7

 50% to 99% ................................................. 12.1 1.0 1.0 0.8 0.6 14.9

 25% to 49% ................................................. 6.4 1.2 0.4 0.2 Q 17.2

 1% to 24% ................................................... 3.5 0.7 0.3 Q Q 17.0

Large Tree(s) that

Shade the Home

 Yes .............................................................. 41.5 1.9 2.6 4.2 3.1 7.9

 No ................................................................ 39.3 2.8 2.6 3.2 2.9 8.2

Central Air-Conditioner Age

(excludes systems for more than one

housing unit)

 Less than 2 Years ....................................... 6.1 0.2 0.3 0.6 0.4 24.1

 2 to 4 Years ................................................. 10.1 0.2 0.6 0.9 1.0 16.9

 5 to 9 Years ................................................. 15.4 0.5 0.7 1.6 1.8 14.6

 10 to 19 Years ............................................. 15.0 Q 1.3 1.2 1.7 16.6

 20 Years or More ......................................... 5.7 0.2 0.6 0.6 0.4 24.2

 Don’t Know .................................................. 3.7 Q 0.4 0.8 0.3 24.1

Central Air-Conditioning Use

 Only a Few Times ....................................... 16.8 0.7 2.9 0.4 0.5 14.6

 Quite a Bit .................................................... 12.1 0.4 0.8 1.1 1.2 15.9

 All Summer .................................................. 28.4 0.2 0.3 4.7 3.9 9.1

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-7a. Air Conditioning by Four Most Populated States, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

Four Most Populated States

RSE

Row

Factors

New York California Texas Florida

0.4 1.1 1.7 1.2 1.2

Pays for Electricity for Central

Air-Conditioning

 Yes .............................................................. 55.5 1.3 3.9 5.7 5.6 6.9

 No ................................................................ 2.0 Q Q 0.5 Q 30.9

Age of Most-Used Room Air Conditioner

 Less than 2 Years ....................................... 3.1 0.4 0.2 0.2 Q 23.0

 2 to 4 Years ................................................. 5.3 1.1 0.3 0.4 Q 14.1

 5 to 9 Years ................................................. 6.4 1.2 0.2 0.4 0.1 17.1

 10 or 19 Years ............................................. 4.3 0.5 0.1 0.1 Q 23.1

 20 or More Years ......................................... 2.0 0.2 0.2 Q Q 24.9

 Don’t Know .................................................. 2.2 0.1 0.2 Q Q 29.8

Room Air-Conditioning Use

 Only a Few Times ....................................... 13.6 2.4 0.9 0.3 Q 10.8

 Quite a Bit .................................................... 5.0 0.5 0.2 0.2 Q 26.3

 All Summer .................................................. 4.7 0.4 0.1 0.7 Q 25.0

Pays for Electricity for Room

Air-Conditioning

 Yes .............................................................. 21.9 3.2 1.2 1.1 Q 10.5

 No ................................................................ 1.5 0.2 Q 0.1 Q 38.4

1 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does include

the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as if the fuel

was electricity. 2 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million households

using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. 

• See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-8a. Air Conditioning by Urban/Rural Location, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

Urban/Rural Location1

RSE

Row

Factors

City Town Suburbs Rural

0.5 0.8 1.4 1.3 1.4

Households With Electric

Air-Conditioning Equipment ...................... 82.9 36.8 13.6 18.9 13.6 4.3

 Air Conditioners Not Used ........................... 2.1 1.2 0.2 0.4 0.3 21.4

Households Using Electric

Air-Conditioning2 ........................................ 80.8 35.6 13.4 18.6 13.3 4.3

Type of Electric Air-Conditioning Used

 Central Air-Conditioning3 ............................ 57.5 23.6 8.6 15.8 9.4 5.1

 Without a Heat Pump ................................ 46.2 19.3 7.4 13.1 6.4 6.3

 With a Heat Pump ..................................... 11.3 4.4 1.2 2.8 2.9 13.1

 Room Air-Conditioning ................................ 23.3 12.0 4.8 2.7 3.9 7.4

 1 Unit ......................................................... 12.8 6.8 2.6 1.3 2.1 9.9

 2 Units ....................................................... 7.5 3.4 1.7 1.0 1.4 10.3

 3 or More Units .......................................... 3.0 1.7 0.5 0.4 0.4 16.8

Number of Rooms AirConditioned in Summer 2001

 One or Two .................................................. 12.3 6.5 2.3 1.5 1.9 9.0

 Three ........................................................... 9.2 5.1 1.6 1.5 1.0 12.9

 Four ............................................................ 12.0 5.8 2.1 2.1 2.0 9.7

 Five or More ................................................ 47.3 18.2 7.3 13.5 8.3 5.8

Percentage of Rooms

Air-Conditioned

 100% ........................................................... 58.8 25.7 9.2 14.8 9.2 5.2

 50% to 99% ................................................. 12.1 5.1 2.2 2.4 2.4 9.2

 25% to 49% ................................................. 6.4 3.0 1.6 0.8 1.0 12.0

 1% to 24% ................................................... 3.5 1.8 0.4 0.5 0.7 15.1

Large Tree(s) that

Shade the Home

 Yes .............................................................. 41.5 16.7 6.8 9.9 8.0 5.8

 No ................................................................ 39.3 18.8 6.6 8.6 5.2 6.7

Central Air-Conditioner Age

(excludes systems for more than one

housing unit)

 Less than 2 Years ....................................... 6.1 1.9 1.1 1.5 1.5 13.4

 2 to 4 Years ................................................. 10.1 3.7 1.8 2.6 2.0 10.5

 5 to 9 Years ................................................. 15.4 6.1 1.7 4.9 2.7 9.6

 10 to 19 Years ............................................. 15.0 5.8 2.5 4.4 2.3 9.3

 20 Years or More ......................................... 5.7 2.8 0.9 1.4 0.5 14.2

 Don’t Know .................................................. 3.7 2.1 0.5 0.9 0.3 19.9

Central Air-Conditioning Use

 Only a Few Times ....................................... 16.8 7.2 3.1 4.1 2.4 9.0

 Quite a Bit .................................................... 12.1 4.5 1.7 3.9 1.9 9.1

 All Summer .................................................. 28.4 11.7 3.9 7.8 5.0 7.2

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-8a. Air Conditioning by Urban/Rural Location, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

Urban/Rural Location1

RSE

Row

Factors

City Town Suburbs Rural

0.5 0.8 1.4 1.3 1.4

Pays for Electricity for Central

Air-Conditioning

 Yes .............................................................. 55.5 22.2 8.4 15.6 9.2 5.3

 No ................................................................ 2.0 1.4 0.2 0.3 0.1 31.0

Age of Most-Used Room Air Conditioner

 Less than 2 Years ....................................... 3.1 1.6 0.6 0.4 0.5 17.7

 2 to 4 Years ................................................. 5.3 2.8 1.1 0.6 0.7 12.1

 5 to 9 Years ................................................. 6.4 3.1 1.2 0.8 1.3 12.6

 10 or 19 Years ............................................. 4.3 2.0 0.9 0.4 0.9 14.2

 20 or More Years ......................................... 2.0 0.9 0.5 0.4 0.3 22.2

 Don’t Know .................................................. 2.2 1.5 0.4 0.2 0.1 23.9

Room Air-Conditioning Use

 Only a Few Times ....................................... 13.6 6.8 2.9 1.8 2.1 8.6

 Quite a Bit .................................................... 5.0 2.7 0.8 0.6 1.0 15.1

 All Summer .................................................. 4.7 2.4 1.1 0.4 0.9 14.0

Pays for Electricity for Room

Air-Conditioning

 Yes .............................................................. 21.9 11.2 4.5 2.4 3.8 7.2

 No ................................................................ 1.5 0.8 0.3 Q 0.1 29.7

1 Based on the household respondent’s description rather than the Federal Government definition. 2 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does include

the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as if the fuel

was electricity. 3 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million households

using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. 

• See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-9a. Air Conditioning by Northeast Census Region, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

Northeast Census Region

RSE

Row

Factors

Total

Census Division

Middle Atlantic New England

0.5 1.0 1.2 1.8

Households With Electric

Air-Conditioning Equipment ...................... 82.9 14.5 11.3 3.2 3.3

 Air Conditioners Not Used ........................... 2.1 0.3 0.3 Q 28.3

Households Using Electric

Air-Conditioning1 ........................................ 80.8 14.2 11.1 3.2 3.4

Type of Electric Air-Conditioning Used

 Central Air-Conditioning2 ............................ 57.5 5.7 4.9 0.8 8.9

 Without a Heat Pump ................................ 46.2 5.2 4.5 0.7 9.2

 With a Heat Pump ..................................... 11.3 0.4 0.4 Q 26.0

 Room Air-Conditioning ................................ 23.3 8.5 6.1 2.4 5.6

 1 Unit ......................................................... 12.8 4.4 2.9 1.4 8.5

 2 Units ....................................................... 7.5 2.8 2.1 0.7 7.4

 3 or More Units .......................................... 3.0 1.3 1.1 0.3 13.2

Number of Rooms AirConditioned in Summer 2001

 One or Two .................................................. 12.3 4.9 3.5 1.4 6.7

 Three ........................................................... 9.2 2.0 1.5 0.5 11.4

 Four ............................................................ 12.0 1.8 1.5 0.3 13.6

 Five or More ................................................ 47.3 5.5 4.6 0.9 8.2

Percentage of Rooms

Air-Conditioned

 100% ........................................................... 58.8 7.1 6.1 1.0 7.1

 50% to 99% ................................................. 12.1 2.7 1.9 0.9 10.1

 25% to 49% ................................................. 6.4 2.7 2.2 0.6 10.6

 1% to 24% ................................................... 3.5 1.6 0.9 0.7 10.2

Large Tree(s) that

Shade the Home

 Yes .............................................................. 41.5 6.2 4.6 1.6 6.5

 No ................................................................ 39.3 8.0 6.4 1.6 4.9

Central Air-Conditioner Age

(excludes systems for more than one

housing unit)

 Less than 2 Years ....................................... 6.1 0.6 0.6 Q 15.4

 2 to 4 Years ................................................. 10.1 0.7 0.6 Q 14.3

 5 to 9 Years ................................................. 15.4 1.6 1.4 0.2 16.5

 10 to 19 Years ............................................. 15.0 1.7 1.5 0.2 16.2

 20 Years or More ......................................... 5.7 0.6 0.5 Q 17.6

 Don’t Know .................................................. 3.7 Q Q Q 22.0

Central Air-Conditioning Use

 Only a Few Times ....................................... 16.8 2.8 2.4 0.4 11.7

 Quite a Bit .................................................... 12.1 1.3 1.2 Q 14.2

 All Summer .................................................. 28.4 1.6 1.4 0.2 15.0

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-9a. Air Conditioning by Northeast Census Region, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

Northeast Census Region

RSE

Row

Factors

Total

Census Division

Middle Atlantic New England

0.5 1.0 1.2 1.8

Pays for Electricity for Central

Air-Conditioning

 Yes .............................................................. 55.5 5.5 4.7 0.8 8.9

 No ................................................................ 2.0 Q Q Q 30.9

Age of Most-Used Room Air Conditioner

 Less than 2 Years ....................................... 3.1 1.1 0.7 0.3 17.5

 2 to 4 Years ................................................. 5.3 2.3 1.8 0.5 9.7

 5 to 9 Years ................................................. 6.4 2.7 1.9 0.8 11.1

 10 or 19 Years ............................................. 4.3 1.4 1.0 0.4 11.4

 20 or More Years ......................................... 2.0 0.4 0.3 Q 25.5

 Don’t Know .................................................. 2.2 0.6 0.4 0.2 23.6

Room Air-Conditioning Use

 Only a Few Times ....................................... 13.6 5.8 4.1 1.8 6.5

 Quite a Bit .................................................... 5.0 1.7 1.3 0.4 13.9

 All Summer .................................................. 4.7 1.0 0.8 0.2 18.5

Pays for Electricity for Room

Air-Conditioning

 Yes .............................................................. 21.9 7.9 5.7 2.2 6.1

 No ................................................................ 1.5 0.6 0.5 0.2 25.8

1 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does

include the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as

if the fuel was electricity. 2 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million

households using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. 

• See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-10a. Air Conditioning by Midwest Census Region, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

Midwest Census Region

RSE

Row

Factors

Total

Census Division

East North Central West North Central

0.5 1.0 1.2 1.4

Households With Electric

Air-Conditioning Equipment ...................... 82.9 20.5 13.6 6.8 2.2

 Air Conditioners Not Used ........................... 2.1 0.3 Q Q 27.5

Households Using Electric

Air-Conditioning1 ........................................ 80.8 20.2 13.4 6.7 2.3

Type of Electric Air-Conditioning Used

 Central Air-Conditioning2 ............................ 57.5 14.3 9.5 4.8 3.8

 Without a Heat Pump ................................ 46.2 13.6 9.0 4.6 3.9

 With a Heat Pump ..................................... 11.3 0.7 0.5 0.2 22.7

 Room Air-Conditioning ................................ 23.3 5.8 3.9 1.9 7.1

 1 Unit ......................................................... 12.8 3.6 2.4 1.1 8.3

 2 Units ....................................................... 7.5 1.7 1.1 0.6 10.4

 3 or More Units .......................................... 3.0 0.5 0.4 Q 16.3

Number of Rooms AirConditioned in Summer 2001

 One or Two .................................................. 12.3 2.5 1.9 0.6 11.3

 Three ........................................................... 9.2 2.2 1.5 0.6 14.5

 Four ............................................................ 12.0 2.9 1.5 1.4 10.1

 Five or More ................................................ 47.3 12.6 8.5 4.1 4.2

Percentage of Rooms

Air-Conditioned

 100% ........................................................... 58.8 15.0 10.0 5.0 3.1

 50% to 99% ................................................. 12.1 3.1 1.9 1.1 8.4

 25% to 49% ................................................. 6.4 1.4 0.9 0.5 12.2

 1% to 24% ................................................... 3.5 0.7 0.6 Q 16.6

Large Tree(s) that

Shade the Home

 Yes .............................................................. 41.5 10.6 7.0 3.6 4.3

 No ................................................................ 39.3 9.5 6.4 3.1 5.0

Central Air-Conditioner Age

(excludes systems for more than one

housing unit)

 Less than 2 Years ....................................... 6.1 1.6 1.0 0.6 13.4

 2 to 4 Years ................................................. 10.1 2.4 1.8 0.6 9.7

 5 to 9 Years ................................................. 15.4 3.7 2.5 1.2 9.2

 10 to 19 Years ............................................. 15.0 4.1 2.8 1.3 9.6

 20 Years or More ......................................... 5.7 1.7 0.9 0.8 10.1

 Don’t Know .................................................. 3.7 0.7 0.4 0.3 21.7

Central Air-Conditioning Use

 Only a Few Times ....................................... 16.8 6.0 4.2 1.9 7.0

 Quite a Bit .................................................... 12.1 3.9 3.0 0.9 9.6

 All Summer .................................................. 28.4 4.4 2.4 2.0 9.4

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-10a. Air Conditioning by Midwest Census Region, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

Midwest Census Region

RSE

Row

Factors

Total

Census Division

East North Central West North Central

0.5 1.0 1.2 1.4

Pays for Electricity for Central

Air-Conditioning

 Yes .............................................................. 55.5 14.0 9.2 4.8 3.9

 No ................................................................ 2.0 Q Q Q 26.6

Age of Most-Used Room Air Conditioner

 Less than 2 Years ....................................... 3.1 0.8 0.6 0.2 22.0

 2 to 4 Years ................................................. 5.3 1.1 0.8 0.3 15.5

 5 to 9 Years ................................................. 6.4 1.2 0.8 0.4 12.8

 10 or 19 Years ............................................. 4.3 1.3 0.8 0.5 15.3

 20 or More Years ......................................... 2.0 0.7 0.5 0.2 19.2

 Don’t Know .................................................. 2.2 0.7 0.5 0.2 17.8

Room Air-Conditioning Use

 Only a Few Times ....................................... 13.6 3.7 2.6 1.1 8.1

 Quite a Bit .................................................... 5.0 1.1 0.8 0.3 17.4

 All Summer .................................................. 4.7 1.1 0.6 0.5 17.2

Pays for Electricity for Room

Air-Conditioning

 Yes .............................................................. 21.9 5.5 3.6 1.9 6.2

 No ................................................................ 1.5 Q Q Q 34.6

1 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does

include the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as

if the fuel was electricity. 2 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million

households using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. 

• See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-11a. Air Conditioning by South Census Region, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

South Census Region

RSE

Row

Factors

Total

Census Division

South Atlantic East South Central West South Central

0.5 0.8 1.2 1.3 1.4

Households With Electric

Air-Conditioning Equipment ...................... 82.9 37.2 19.3 6.4 11.5 1.5

 Air Conditioners Not Used ........................... 2.1 0.4 Q Q Q 28.2

Households Using Electric

Air-Conditioning1 ........................................ 80.8 36.9 19.0 6.4 11.5 1.6

Type of Electric Air-Conditioning Used

 Central Air-Conditioning2 ............................ 57.5 30.4 16.1 5.0 9.2 2.8

 Without a Heat Pump ................................ 46.2 22.1 10.4 3.4 8.3 5.6

 With a Heat Pump ..................................... 11.3 8.3 5.7 1.6 0.9 14.6

 Room Air-Conditioning ................................ 23.3 6.4 2.9 1.3 2.2 9.0

 1 Unit ......................................................... 12.8 2.9 1.3 0.6 0.9 10.2

 2 Units ....................................................... 7.5 2.6 1.3 0.5 0.8 12.0

 3 or More Units .......................................... 3.0 1.0 0.3 0.2 0.5 22.4

Number of Rooms AirConditioned in Summer 2001

 One or Two .................................................. 12.3 3.0 1.6 0.5 0.8 15.8

 Three ........................................................... 9.2 3.7 1.5 0.6 1.6 12.3

 Four ............................................................ 12.0 5.6 2.9 1.0 1.7 9.4

 Five or More ................................................ 47.3 24.6 13.0 4.3 7.3 3.9

Percentage of Rooms

Air-Conditioned

 100% ........................................................... 58.8 30.2 15.3 5.3 9.6 2.4

 50% to 99% ................................................. 12.1 4.5 2.6 0.6 1.3 9.9

 25% to 49% ................................................. 6.4 1.3 0.8 0.2 0.4 17.8

 1% to 24% ................................................... 3.5 0.7 0.4 0.2 Q 20.3

Large Tree(s) that

Shade the Home

 Yes .............................................................. 41.5 20.1 9.7 3.6 6.8 5.0

 No ................................................................ 39.3 16.8 9.3 2.8 4.7 6.5

Central Air-Conditioner Age

(excludes systems for more than one

housing unit)

 Less than 2 Years ....................................... 6.1 3.2 1.5 0.7 1.0 12.4

 2 to 4 Years ................................................. 10.1 5.5 3.1 0.9 1.6 11.8

 5 to 9 Years ................................................. 15.4 8.9 5.0 1.5 2.4 7.1

 10 to 19 Years ............................................. 15.0 7.3 4.2 1.2 1.9 9.0

 20 Years or More ......................................... 5.7 2.4 1.1 0.3 1.0 15.5

 Don’t Know .................................................. 3.7 2.2 0.9 0.3 1.1 19.4

Central Air-Conditioning Use

 Only a Few Times ....................................... 16.8 4.1 2.8 0.7 0.6 11.0

 Quite a Bit .................................................... 12.1 5.5 3.0 0.8 1.7 8.7

 All Summer .................................................. 28.4 20.7 10.3 3.5 6.9 4.5

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-11a. Air Conditioning by South Census Region, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

South Census Region

RSE

Row

Factors

Total

Census Division

South Atlantic East South Central West South Central

0.5 0.8 1.2 1.3 1.4

Pays for Electricity for Central

Air-Conditioning

 Yes .............................................................. 55.5 29.2 15.5 4.9 8.8 2.8

 No ................................................................ 2.0 1.3 0.7 Q 0.5 20.7

Age of Most-Used Room Air Conditioner

 Less than 2 Years ....................................... 3.1 0.8 0.5 Q 0.3 22.2

 2 to 4 Years ................................................. 5.3 1.4 0.6 0.2 0.5 13.4

 5 to 9 Years ................................................. 6.4 2.1 0.9 0.5 0.7 16.3

 10 or 19 Years ............................................. 4.3 1.1 0.5 0.3 0.3 16.7

 20 or More Years ......................................... 2.0 0.5 Q Q Q 28.5

 Don’t Know .................................................. 2.2 0.5 Q Q 0.3 31.3

Room Air-Conditioning Use

 Only a Few Times ....................................... 13.6 2.3 1.2 0.4 0.6 15.1

 Quite a Bit .................................................... 5.0 1.7 0.9 0.3 0.6 17.5

 All Summer .................................................. 4.7 2.5 0.8 0.6 1.0 14.3

Pays for Electricity for Room

Air-Conditioning

 Yes .............................................................. 21.9 6.0 2.6 1.3 2.1 8.6

 No ................................................................ 1.5 0.4 Q Q Q 39.0

1 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does include

the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as if the fuel

was electricity. 2 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million households

using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. 

• See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-12a. Air Conditioning by West Census Region, 

 Million U.S. Households, 2001

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

West Census Region

RSE

Row

Factors

Total

Census Division

Mountain Pacific

0.4 1.2 1.7 1.4

Households With Electric

Air-Conditioning Equipment ...................... 82.9 10.7 3.4 7.2 7.1

 Air Conditioners Not Used ........................... 2.1 1.1 0.2 0.9 15.5

Households Using Electric

Air-Conditioning1 ........................................ 80.8 9.6 3.2 6.3 7.2

Type of Electric Air-Conditioning Used

 Central Air-Conditioning2 ............................ 57.5 7.1 2.6 4.5 8.5

 Without a Heat Pump ................................ 46.2 5.2 1.8 3.4 11.2

 With a Heat Pump ..................................... 11.3 1.8 0.7 1.1 10.9

 Room Air-Conditioning ................................ 23.3 2.5 0.6 1.9 10.1

 1 Unit ......................................................... 12.8 2.0 0.5 1.5 11.6

 2 Units ....................................................... 7.5 0.4 Q 0.3 17.4

 3 or More Units .......................................... 3.0 Q Q Q 27.6

Number of Rooms AirConditioned in Summer 2001

 One or Two .................................................. 12.3 1.9 0.5 1.4 11.2

 Three ........................................................... 9.2 1.4 0.2 1.1 22.5

 Four ............................................................ 12.0 1.8 0.8 1.0 15.9

 Five or More ................................................ 47.3 4.5 1.7 2.8 8.2

Percentage of Rooms

Air-Conditioned

 100% ........................................................... 58.8 6.4 2.3 4.1 7.8

 50% to 99% ................................................. 12.1 1.7 0.5 1.3 18.6

 25% to 49% ................................................. 6.4 0.9 0.3 0.6 19.7

 1% to 24% ................................................... 3.5 0.5 Q 0.4 20.4

Large Tree(s) that

Shade the Home

 Yes .............................................................. 41.5 4.6 1.4 3.2 7.4

 No ................................................................ 39.3 5.0 1.8 3.1 11.2

Central Air-Conditioner Age

(excludes systems for more than one

housing unit)

 Less than 2 Years ....................................... 6.1 0.6 0.3 0.3 16.8

 2 to 4 Years ................................................. 10.1 1.5 0.7 0.7 14.6

 5 to 9 Years ................................................. 15.4 1.3 0.5 0.8 14.0

 10 to 19 Years ............................................. 15.0 2.0 0.4 1.5 13.9

 20 Years or More ......................................... 5.7 0.9 0.3 0.6 23.1

 Don’t Know .................................................. 3.7 0.6 0.2 0.4 22.9

Central Air-Conditioning Use

 Only a Few Times ....................................... 16.8 3.9 0.7 3.2 14.1

 Quite a Bit .................................................... 12.1 1.4 0.6 0.8 15.7

 All Summer .................................................. 28.4 1.7 1.3 0.4 12.9

See footnotes at end of table.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables
Table HC4-12a. Air Conditioning by West Census Region, 

 Million U.S. Households, 2001 (Continued)

Air Conditioning

Characteristics

RSE Column Factor:

Total

U.S.

West Census Region

RSE

Row

Factors

Total

Census Division

Mountain Pacific

0.4 1.2 1.7 1.4

Pays for Electricity for Central

Air-Conditioning

 Yes .............................................................. 55.5 6.8 2.4 4.4 8.3

 No ................................................................ 2.0 0.2 0.2 Q 33.9

Age of Most-Used Room Air Conditioner

 Less than 2 Years ....................................... 3.1 0.3 Q 0.2 20.4

 2 to 4 Years ................................................. 5.3 0.5 Q 0.5 18.5

 5 to 9 Years ................................................. 6.4 0.5 Q 0.3 16.2

 10 or 19 Years ............................................. 4.3 0.5 0.2 0.3 22.7

 20 or More Years ......................................... 2.0 0.4 Q 0.3 26.9

 Don’t Know .................................................. 2.2 0.4 Q 0.3 29.9

Room Air-Conditioning Use

 Only a Few Times ....................................... 13.6 1.8 0.4 1.4 12.3

 Quite a Bit .................................................... 5.0 0.5 0.2 0.3 22.9

 All Summer .................................................. 4.7 0.2 Q Q 26.9

Pays for Electricity for Room

Air-Conditioning

 Yes .............................................................. 21.9 2.4 0.6 1.8 10.2

 No ................................................................ 1.5 Q Q Q 53.5

1 The number of households, where the end use is electric air-conditioning, does not include households that did not use their equipment (2.1 million). It does

include the small number of households where the fuel for central air-conditioning equipment was something other than electricity; those households were treated as

if the fuel was electricity. 2 The 2001 RECS reported 800,000 households having both central air-conditioning and room/wall air-conditioners, with 600,000 households using both central

air-conditioning and 200,000 households using only room/wall air-conditioners. These room/wall air-conditioners are not included in the count of 23.3 million

households using room/wall air-conditioners. Note: This applies to all occurrences of central air-conditioning.

Q = Data withheld either because the Relative Standard Error (RSE) was greater than 50 percent or fewer than 10 households were sampled.

Notes: • To obtain the RSE percentage for any table cell, multiply the corresponding column and row factors. • Because of rounding, data may not sum to totals. 

• See "Glossary" for definition of terms used in this report.

Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2001 Residential Energy Consumption Survey.

Energy Information Administration

2001 Residential Energy Consumption Survey: Housing Characteristics Tables