Total................................................................... 111.1 72.1 7.6 7.8 16.7 6.9

Do Not Have Cooling Equipment..................... 17.8 10.9 1.5 1.5 2.8 1.2

Have Coolling Equipment................................ 93.3 61.2 6.1 6.3 13.9 5.8

Use Cooling Equipment................................... 91.4 60.3 6.0 6.1 13.5 5.5

Have Equipment But Do Not Use it................. 1.9 1.0 Q 0.2 0.4 Q

Air-Conditioning Equipment1, 2

Central System............................................... 65.9 47.5 4.0 2.8 7.9 3.7

Without a Heat Pump.................................. 53.5 37.8 3.4 2.2 7.0 3.1

With a Heat Pump....................................... 12.3 9.7 0.6 0.5 1.0 0.6

Window/Wall Units.......................................... 28.9 14.9 2.3 3.5 6.0 2.1

1 Unit........................................................... 14.5 6.6 1.0 1.6 4.2 1.2

2 Units......................................................... 9.1 4.6 0.9 1.4 1.5 0.6

3 or More Units............................................ 5.4 3.7 0.5 0.5 0.3 0.3

Central Air-Conditioning.................................. 65.9 47.5 4.0 2.8 7.9 3.7

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit........................................ 64.2 47.3 3.9 2.5 6.8 3.7

Two or More Housing Units......................... 1.7 Q Q Q 1.1 Q

Do Not Have Central A/C Equipment........... 45.2 24.6 3.6 5.0 8.8 3.2

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None............................................................ 1.4 0.7 QQQQ

1.................................................................. 0.7 Q N Q 0.4 Q

2.................................................................. 2.1 1.0 Q Q 0.7 0.2

3.................................................................. 7.5 3.8 0.7 0.6 2.0 0.4

4.................................................................. 7.9 2.8 0.8 0.6 2.6 1.0

5 or More..................................................... 46.3 38.9 2.3 1.3 2.0 1.9

Proportion of Rooms Air-Conditioned

None............................................................ 1.4 0.7 QQQQ

Some, But Not All of the Rooms.................. 8.4 6.7 0.7 Q 0.5 0.4

All of the Rooms.......................................... 56.1 40.0 3.2 2.6 7.2 3.1

Frequency of Central Air-Conditioner Use

Never........................................................... 1.4 0.7 QQQQ

Only a Few Times When Needed................ 11.4 7.4 1.1 0.6 1.8 0.5

Quite a Bit................................................... 12.6 8.7 1.0 0.5 1.8 0.7

All Summer.................................................. 40.5 30.7 1.8 1.6 4.1 2.3

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years.................................... 9.0 7.3 0.6 Q 0.5 0.3

2 to 4 Years............................................. 11.0 8.4 0.6 0.4 0.9 0.7

5 to 9 Years............................................. 16.3 13.0 0.8 0.4 1.0 1.1

10 to 19 Years......................................... 16.8 12.7 1.1 0.5 1.5 1.0

20 Years or More..................................... 6.5 4.1 0.5 0.3 1.5 0.2

Don't Know.............................................. 4.5 1.8 0.5 0.5 1.5 Q

Apartments in Buildings 

With-- Housing 

Units 

(millions)

Single-Family Units

Detached

Type of Housing Unit

Table HC2.6 Air Conditioning Characteristics by Type of Housing Unit, 2005

 Million U.S. Housing Units

Air Conditioning Characteristics Attached 2 to 4 Units 5 or More 

Units

Mobile 

Homes

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristics Tables
Apartments in Buildings 

With-- Housing 

Units 

(millions)

Single-Family Units

Detached

Type of Housing Unit

Table HC2.6 Air Conditioning Characteristics by Type of Housing Unit, 2005

 Million U.S. Housing Units

Air Conditioning Characteristics Attached 2 to 4 Units 5 or More 

Units

Mobile 

Homes

Used by Two or More Housing Units

Less than 2 Years.................................... Q N N N Q N

2 to 4 Years............................................. Q N Q N Q N

5 to 9 Years............................................. 0.3 Q N Q Q Q

10 to 19 Years......................................... 0.3 Q N N Q N

20 Years or More..................................... 0.3 Q N Q Q N

Don't Know.............................................. 0.7 N N Q Q N

Household Pays for Electricity

for Central Air-Conditioning

Yes.............................................................. 63.6 47.1 3.9 2.6 6.4 3.6

No............................................................... 2.3 0.3 Q Q 1.6 Q

Window/Wall Unit Air-Conditioning................. 28.9 14.9 2.3 3.5 6.0 2.1

Frequency Most-Used Unit Used

Never........................................................... 0.6 0.3 N Q Q Q

Only a Few Times When Needed................ 12.1 6.6 0.9 1.4 2.5 0.6

Quite a Bit................................................... 7.5 4.0 0.7 0.9 1.4 0.6

All Summer.................................................. 8.6 4.0 0.8 1.0 1.9 0.9

Age of Most-Used Unit

Less than 2 Years....................................... 6.4 3.1 0.5 1.2 1.4 0.3

2 to 4 Years................................................. 7.8 3.9 0.7 1.0 1.4 0.9

5 to 9 Years................................................. 7.0 4.1 0.6 0.7 1.2 0.4

10 to 19 Years............................................. 3.7 2.3 0.2 0.3 0.5 0.3

20 Years or More......................................... 2.1 1.0 Q Q 0.7 Q

Don't Know.................................................. 1.8 0.5 Q 0.2 0.8 Q

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes.............................................................. 26.1 14.3 2.2 3.3 4.4 1.9

No............................................................... 2.2 0.3 Q Q 1.5 Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristics Tables
 Million U.S. Housing Units

Total......................................................................... 111.1 78.1 64.1 4.2 1.8 2.3 5.7

Do Not Have Cooling Equipment........................... 17.8 11.3 9.3 0.6 Q 0.4 0.9

Have Coolling Equipment....................................... 93.3 66.8 54.7 3.6 1.7 1.9 4.8

Use Cooling Equipment......................................... 91.4 65.8 54.0 3.6 1.7 1.9 4.7

Have Equipment But Do Not Use it........................ 1.9 1.1 0.8 Q N Q Q

Air-Conditioning Equipment1, 2

Central System...................................................... 65.9 51.7 43.9 2.5 0.7 1.6 3.1

Without a Heat Pump......................................... 53.5 41.1 34.8 2.1 0.5 1.2 2.6

With a Heat Pump.............................................. 12.3 10.6 9.1 0.4 Q 0.3 0.6

Window/Wall Units................................................. 28.9 16.5 12.0 1.3 1.0 0.4 1.7

1 Unit................................................................. 14.5 7.2 5.4 0.5 0.2 Q 0.9

2 Units................................................................ 9.1 5.5 3.7 0.5 0.6 Q 0.6

3 or More Units.................................................. 5.4 3.8 2.9 0.4 Q N 0.2

Central Air-Conditioning......................................... 65.9 51.7 43.9 2.5 0.7 1.6 3.1

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit............................................... 64.2 51.4 43.7 2.5 0.7 1.5 3.1

Two or More Housing Units................................ 1.7 0.3 Q N Q Q Q

Do Not Have Central A/C Equipment................. 45.2 26.4 20.2 1.7 1.1 0.7 2.6

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None.................................................................. 1.4 0.8 0.6 Q N Q Q

1......................................................................... 0.7 Q Q N N Q Q

2......................................................................... 2.1 1.2 0.9 Q N Q Q

3......................................................................... 7.5 4.7 3.6 0.4 Q Q 0.4

4......................................................................... 7.9 4.4 2.5 0.3 Q 0.6 0.8

5 or More............................................................ 46.3 40.4 36.1 1.6 0.4 0.5 1.7

Proportion of Rooms Air-Conditioned

None.................................................................. 1.4 0.8 0.6 Q N Q Q

Some, But Not All of the Rooms........................ 8.4 7.2 6.3 0.5 Q Q 0.4

All of the Rooms................................................. 56.1 43.7 37.0 1.9 0.7 1.4 2.7

Frequency of Central Air-Conditioner Use

Never................................................................. 1.4 0.8 0.6 Q N Q Q

Only a Few Times When Needed....................... 11.4 8.8 7.0 0.9 Q 0.4 0.4

Quite a Bit.......................................................... 12.6 9.7 8.2 0.5 Q Q 0.6

All Summer........................................................ 40.5 32.3 28.1 1.0 0.4 0.9 2.0

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years.......................................... 9.0 7.6 6.7 0.4 Q Q 0.3

2 to 4 Years.................................................... 11.0 9.1 7.8 0.4 Q Q 0.6

5 to 9 Years.................................................... 16.3 14.2 12.3 0.6 Q Q 0.9

10 to 19 Years................................................ 16.8 14.2 12.0 0.7 Q 0.4 0.9

20 Years or More............................................ 6.5 4.5 3.6 0.3 Q 0.3 Q

Don't Know..................................................... 4.5 1.7 1.3 QQQQ

Mobile 

Homes

Table HC3.6 Air Conditioning Characteristics by Owner-Occupied Housing Units, 2005

Air Conditioning Characteristics Detached Attached 2 to 4 

Units

 OwnerOccupied 

Housing 

Units 

(millions)

Type of Owner-Occupied Housing Unit

U.S.

Housing 

Units 

(millions

Single-Family Units Apartments in 

Buildings With--

5 or More 

Units

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Mobile 

Homes

Table HC3.6 Air Conditioning Characteristics by Owner-Occupied Housing Units, 2005

Air Conditioning Characteristics Detached Attached 2 to 4 

Units

 OwnerOccupied 

Housing 

Units 

(millions)

Type of Owner-Occupied Housing Unit

U.S.

Housing 

Units 

(millions

Single-Family Units Apartments in 

Buildings With--

5 or More 

Units

Used by Two or More Housing Units

Less than 2 Years.......................................... Q NNNNNN

2 to 4 Years.................................................... Q NNNNNN

5 to 9 Years.................................................... 0.3 Q Q N N Q Q

10 to 19 Years................................................ 0.3 Q Q N N Q N

20 Years or More............................................ 0.3 Q Q N Q N N

Don't Know..................................................... 0.7 NNNNNN

Household Pays for Electricity

for Central Air-Conditioning

Yes.................................................................... 63.6 51.5 43.7 2.5 0.7 1.5 3.1

No...................................................................... 2.3 0.3 Q Q N Q Q

Window/Wall Unit Air-Conditioning....................... 28.9 16.5 12.0 1.3 1.0 0.4 1.7

Frequency Most-Used Unit Used

Never................................................................. 0.6 0.3 0.3 N N N Q

Only a Few Times When Needed....................... 12.1 7.2 5.4 0.6 0.5 Q 0.5

Quite a Bit.......................................................... 7.5 4.6 3.3 0.4 0.3 Q 0.5

All Summer........................................................ 8.6 4.4 3.1 0.3 Q Q 0.8

Age of Most-Used Unit

Less than 2 Years.............................................. 6.4 3.4 2.5 0.3 0.3 Q 0.2

2 to 4 Years....................................................... 7.8 4.6 3.1 0.4 Q Q 0.7

5 to 9 Years....................................................... 7.0 4.5 3.5 0.4 0.3 N 0.3

10 to 19 Years.................................................... 3.7 2.5 2.0 Q Q Q 0.3

20 Years or More............................................... 2.1 1.0 0.7 QQQQ

Don't Know......................................................... 1.8 0.4 0.2 Q N Q Q

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes.................................................................... 26.1 16.0 11.7 1.3 1.0 0.3 1.6

No...................................................................... 2.2 0.2 Q Q N Q Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for central airconditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Total......................................................................... 111.1 78.1 64.1 4.2 1.8 2.3 5.7

Do Not Have Cooling Equipment........................... 17.8 11.3 9.3 0.6 Q 0.4 0.9

Have Coolling Equipment....................................... 93.3 66.8 54.7 3.6 1.7 1.9 4.8

Use Cooling Equipment......................................... 91.4 65.8 54.0 3.6 1.7 1.9 4.7

Have Equipment But Do Not Use it........................ 1.9 1.1 0.8 Q N Q Q

Air-Conditioning Equipment1, 2

Central System...................................................... 65.9 51.7 43.9 2.5 0.7 1.6 3.1

Without a Heat Pump......................................... 53.5 41.1 34.8 2.1 0.5 1.2 2.6

With a Heat Pump.............................................. 12.3 10.6 9.1 0.4 Q 0.3 0.6

Window/Wall Units................................................. 28.9 16.5 12.0 1.3 1.0 0.4 1.7

1 Unit................................................................. 14.5 7.2 5.4 0.5 0.2 Q 0.9

2 Units................................................................ 9.1 5.5 3.7 0.5 0.6 Q 0.6

3 or More Units.................................................. 5.4 3.8 2.9 0.4 Q N 0.2

Central Air-Conditioning......................................... 65.9 51.7 43.9 2.5 0.7 1.6 3.1

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit............................................... 64.2 51.4 43.7 2.5 0.7 1.5 3.1

Two or More Housing Units................................ 1.7 0.3 Q N Q Q Q

Do Not Have Central A/C Equipment................. 45.2 26.4 20.2 1.7 1.1 0.7 2.6

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None.................................................................. 1.4 0.8 0.6 Q N Q Q

1......................................................................... 0.7 Q Q N N Q Q

2......................................................................... 2.1 1.2 0.9 Q N Q Q

3......................................................................... 7.5 4.7 3.6 0.4 Q Q 0.4

4......................................................................... 7.9 4.4 2.5 0.3 Q 0.6 0.8

5 or More............................................................ 46.3 40.4 36.1 1.6 0.4 0.5 1.7

Proportion of Rooms Air-Conditioned

None.................................................................. 1.4 0.8 0.6 Q N Q Q

Some, But Not All of the Rooms........................ 8.4 7.2 6.3 0.5 Q Q 0.4

All of the Rooms................................................. 56.1 43.7 37.0 1.9 0.7 1.4 2.7

Frequency of Central Air-Conditioner Use

Never................................................................. 1.4 0.8 0.6 Q N Q Q

Only a Few Times When Needed....................... 11.4 8.8 7.0 0.9 Q 0.4 0.4

Quite a Bit.......................................................... 12.6 9.7 8.2 0.5 Q Q 0.6

All Summer........................................................ 40.5 32.3 28.1 1.0 0.4 0.9 2.0

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years.......................................... 9.0 7.6 6.7 0.4 Q Q 0.3

2 to 4 Years.................................................... 11.0 9.1 7.8 0.4 Q Q 0.6

5 to 9 Years.................................................... 16.3 14.2 12.3 0.6 Q Q 0.9

10 to 19 Years................................................ 16.8 14.2 12.0 0.7 Q 0.4 0.9

20 Years or More............................................ 6.5 4.5 3.6 0.3 Q 0.3 Q

Don't Know..................................................... 4.5 1.7 1.3 QQQQ

Mobile 

Homes

Table HC4.6 Air Conditioning Characteristics by Renter-Occupied Housing Units, 2005

Air Conditioning Characteristics Detached Attached 2 to 4 

Units

 RenterOccupied 

Housing 

Units 

(millions)

Type of Renter-Occupied Housing Unit

U.S.

Housing 

Units 

(millions

Single-Family Units Apartments in 

Buildings With--

5 or More 

Units

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Mobile 

Homes

Table HC4.6 Air Conditioning Characteristics by Renter-Occupied Housing Units, 2005

Air Conditioning Characteristics Detached Attached 2 to 4 

Units

 RenterOccupied 

Housing 

Units 

(millions)

Type of Renter-Occupied Housing Unit

U.S.

Housing 

Units 

(millions

Single-Family Units Apartments in 

Buildings With--

5 or More 

Units

Used by Two or More Housing Units

Less than 2 Years.......................................... Q NNNNNN

2 to 4 Years.................................................... Q NNNNNN

5 to 9 Years.................................................... 0.3 Q Q N N Q Q

10 to 19 Years................................................ 0.3 Q Q N N Q N

20 Years or More............................................ 0.3 Q Q N Q N N

Don't Know..................................................... 0.7 NNNNNN

Household Pays for Electricity

for Central Air-Conditioning

Yes.................................................................... 63.6 51.5 43.7 2.5 0.7 1.5 3.1

No...................................................................... 2.3 0.3 Q Q N Q Q

Window/Wall Unit Air-Conditioning....................... 28.9 16.5 12.0 1.3 1.0 0.4 1.7

Frequency Most-Used Unit Used

Never................................................................. 0.6 0.3 0.3 N N N Q

Only a Few Times When Needed....................... 12.1 7.2 5.4 0.6 0.5 Q 0.5

Quite a Bit.......................................................... 7.5 4.6 3.3 0.4 0.3 Q 0.5

All Summer........................................................ 8.6 4.4 3.1 0.3 Q Q 0.8

Age of Most-Used Unit

Less than 2 Years.............................................. 6.4 3.4 2.5 0.3 0.3 Q 0.2

2 to 4 Years....................................................... 7.8 4.6 3.1 0.4 Q Q 0.7

5 to 9 Years....................................................... 7.0 4.5 3.5 0.4 0.3 N 0.3

10 to 19 Years.................................................... 3.7 2.5 2.0 Q Q Q 0.3

20 Years or More............................................... 2.1 1.0 0.7 QQQQ

Don't Know......................................................... 1.8 0.4 0.2 Q N Q Q

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes.................................................................... 26.1 16.0 11.7 1.3 1.0 0.3 1.6

No...................................................................... 2.2 0.2 Q Q N Q Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for central airconditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Total..................................................................... 111.1 14.7 7.4 12.5 12.5 18.9 18.6 17.3 9.2

Do Not Have Cooling Equipment....................... 17.8 3.9 1.8 2.2 2.1 3.1 2.6 1.7 0.4

Have Coolling Equipment.................................. 93.3 10.8 5.6 10.3 10.4 15.8 16.0 15.6 8.8

Use Cooling Equipment..................................... 91.4 10.6 5.5 10.3 10.3 15.3 15.7 15.3 8.6

Have Equipment But Do Not Use it................... 1.9 Q Q Q Q 0.6 0.4 0.3 Q

Air-Conditioning Equipment1, 2 t

Central System................................................. 65.9 3.7 2.6 6.1 6.8 11.2 13.2 13.9 8.2

Without a Heat Pump.................................... 53.5 3.6 2.3 5.5 5.8 9.5 10.1 10.3 6.4

With a Heat Pump......................................... 12.3 Q 0.3 0.6 1.0 1.7 3.1 3.6 1.7

Window/Wall Units............................................ 28.9 7.3 3.2 4.5 3.7 4.8 3.0 1.9 0.7

1 Unit............................................................. 14.5 3.1 1.6 1.9 1.8 2.7 1.8 1.0 0.5

2 Units........................................................... 9.1 2.3 1.0 1.8 1.2 1.5 0.7 0.5 Q

3 or More Units.............................................. 5.4 1.9 0.5 0.8 0.7 0.6 0.4 0.4 Q

Central Air-Conditioning.................................... 65.9 3.7 2.6 6.1 6.8 11.2 13.2 13.9 8.2

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit.......................................... 64.2 3.6 2.6 6.1 6.5 10.8 13.1 13.4 8.0

Two or More Housing Units........................... 1.7 Q N Q Q 0.5 Q 0.5 Q

Do Not Have Central A/C Equipment............. 45.2 10.9 4.8 6.4 5.7 7.7 5.3 3.4 1.1

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None.............................................................. 1.4 Q Q Q Q 0.4 0.3 Q Q

1.................................................................... 0.7 N N QQQQQQ

2.................................................................... 2.1 Q Q Q Q 0.4 0.6 0.4 Q

3.................................................................... 7.5 0.5 0.3 0.6 0.6 1.5 2.1 1.3 0.6

4.................................................................... 7.9 0.5 0.3 0.5 0.7 1.5 1.6 2.1 0.6

5 or More....................................................... 46.3 2.5 1.9 4.7 5.1 7.4 8.7 9.8 6.3

Proportion of Rooms Air-Conditioned

None.............................................................. 1.4 Q Q Q Q 0.4 0.3 Q Q

Some, But Not All of the Rooms.................... 8.4 0.9 0.5 0.7 0.7 1.4 1.6 1.7 0.8

All of the Rooms............................................ 56.1 2.8 2.1 5.3 6.0 9.5 11.3 12.0 7.2

Frequency of Central Air-Conditioner Use

Never............................................................. 1.4 Q Q Q Q 0.4 0.3 Q Q

Only a Few Times When Needed.................. 11.4 0.9 0.7 1.3 1.1 2.1 2.3 2.1 0.9

Quite a Bit..................................................... 12.6 1.0 0.5 1.2 1.6 1.9 2.6 2.5 1.4

All Summer.................................................... 40.5 1.7 1.4 3.5 4.1 6.8 8.1 9.2 5.7

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years...................................... 9.0 0.4 0.4 0.9 0.7 1.0 1.6 0.8 3.2

2 to 4 Years............................................... 11.0 0.8 0.3 0.9 1.0 1.6 1.6 0.7 4.0

5 to 9 Years............................................... 16.3 1.0 0.8 1.2 1.4 2.6 2.1 6.7 0.4

10 to 19 Years........................................... 16.8 0.8 0.7 1.8 1.8 2.2 4.8 4.6 Q

20 Years or More....................................... 6.5 0.4 Q 1.0 0.8 2.2 1.7 Q Q

Don't Know................................................. 4.5 Q Q 0.4 0.8 1.1 1.2 0.5 Q

1970 to 

1979

1980 to 

1989

1990 to 

1999

2000 to 

2005

Table HC5.6 Air Conditioning Characteristics by Year of Construction, 2005

Year of Construction

Housing 

Units 

(millions)

Before 

1940

1940 to 

1949

1950 to 

1959

1960 to 

Air Conditioning Characteristics 1969

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

1970 to 

1979

1980 to 

1989

1990 to 

1999

2000 to 

2005

Table HC5.6 Air Conditioning Characteristics by Year of Construction, 2005

Year of Construction

Housing 

Units 

(millions)

Before 

1940

1940 to 

1949

1950 to 

1959

1960 to 

Air Conditioning Characteristics 1969

Used by Two or More Housing Units

Less than 2 Years...................................... Q NNNNNNNQ

2 to 4 Years............................................... Q NNNNNQNQ

5 to 9 Years............................................... 0.3 Q N N Q Q N Q N

10 to 19 Years........................................... 0.3 N N N QQQQN

20 Years or More....................................... 0.3 N N N Q Q Q N N

Don't Know................................................. 0.7 Q N QQQQQQ

Household Pays for Electricity

for Central Air-Conditioning

Yes................................................................ 63.6 3.7 2.6 5.9 6.3 10.9 12.6 13.5 8.1

No.................................................................. 2.3 Q Q Q 0.4 0.3 0.7 0.4 Q

Window/Wall Unit Air-Conditioning................... 28.9 7.3 3.2 4.5 3.7 4.8 3.0 1.9 0.7

Frequency Most-Used Unit Used

Never............................................................. 0.6 QQQQQQQQ

Only a Few Times When Needed.................. 12.1 3.2 1.2 2.2 1.3 1.9 1.0 0.9 0.4

Quite a Bit..................................................... 7.5 2.1 0.7 0.9 1.2 1.2 0.7 0.6 Q

All Summer.................................................... 8.6 1.9 1.2 1.4 1.2 1.4 1.2 0.3 Q

Age of Most-Used Unit

Less than 2 Years.......................................... 6.4 1.7 0.7 1.1 0.6 1.1 0.7 0.3 0.2

2 to 4 Years................................................... 7.8 2.0 1.0 0.9 0.9 1.2 0.9 0.6 0.3

5 to 9 Years................................................... 7.0 1.8 0.7 1.3 1.1 1.0 0.5 0.6 Q

10 to 19 Years............................................... 3.7 1.0 0.5 0.7 0.4 0.4 0.5 Q Q

20 Years or More........................................... 2.1 0.6 Q 0.3 0.4 0.5 Q Q N

Don't Know.................................................... 1.8 0.3 Q Q 0.2 0.5 0.3 Q Q

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes................................................................ 26.1 6.7 2.9 4.1 3.3 4.2 2.6 1.7 0.6

No.................................................................. 2.2 0.4 Q 0.3 0.4 0.4 0.3 Q Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for central airconditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Table HC6.6 Air Conditioning Characteristics by Number of Household Members, 2005

Total...................................................................... 111.1 30.0 34.8 18.4 15.9 12.0

Do Not Have Cooling Equipment........................ 17.8 5.4 5.3 2.7 2.5 2.0

Have Coolling Equipment.................................... 93.3 24.6 29.6 15.7 13.4 10.0

Use Cooling Equipment...................................... 91.4 24.0 29.1 15.5 13.2 9.7

Have Equipment But Do Not Use it..................... 1.9 0.6 0.5 Q 0.2 0.4

Air-Conditioning Equipment1, 2

Central System................................................... 65.9 15.3 22.6 10.7 9.9 7.3

Without a Heat Pump...................................... 53.5 12.5 17.9 8.7 8.2 6.3

With a Heat Pump........................................... 12.3 2.7 4.8 2.0 1.8 1.0

Window/Wall Units............................................. 28.9 9.5 7.4 5.3 3.7 2.9

1 Unit.............................................................. 14.5 6.5 3.7 2.0 1.3 1.0

2 Units............................................................ 9.1 2.2 2.5 1.8 1.5 1.1

3 or More Units............................................... 5.4 0.9 1.2 1.5 1.0 0.8

Central Air-Conditioning...................................... 65.9 15.3 22.6 10.7 9.9 7.3

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit............................................ 64.2 14.7 22.1 10.4 9.7 7.2

Two or More Housing Units............................. 1.7 0.6 0.5 0.3 Q Q

Do Not Have Central A/C Equipment.............. 45.2 14.8 12.2 7.7 5.9 4.7

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None............................................................... 1.4 0.4 0.3 Q Q 0.3

1..................................................................... 0.7 0.4 QQQQ

2..................................................................... 2.1 0.8 0.9 0.3 Q Q

3..................................................................... 7.5 3.5 2.5 0.6 0.7 0.2

4..................................................................... 7.9 2.3 2.5 1.3 1.1 0.6

5 or More........................................................ 46.3 8.0 16.2 8.2 7.9 6.0

Proportion of Rooms Air-Conditioned

None............................................................... 1.4 0.4 0.3 Q Q 0.3

Some, But Not All of the Rooms..................... 8.4 2.3 3.3 1.5 0.9 0.6

All of the Rooms............................................. 56.1 12.6 19.1 9.0 8.9 6.4

Frequency of Central Air-Conditioner Use

Never.............................................................. 1.4 0.4 0.3 Q Q 0.3

Only a Few Times When Needed................... 11.4 3.5 3.4 1.6 1.6 1.2

Quite a Bit....................................................... 12.6 2.9 4.5 2.0 2.0 1.2

All Summer..................................................... 40.5 8.5 14.4 6.9 6.2 4.5

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years....................................... 9.0 1.7 3.1 1.7 1.5 1.1

2 to 4 Years................................................. 11.0 2.0 3.9 2.1 1.6 1.3

5 to 9 Years................................................. 16.3 3.0 5.7 2.8 2.8 2.0

10 to 19 Years............................................. 16.8 4.2 6.1 2.4 2.6 1.5

20 Years or More......................................... 6.5 2.1 2.4 0.7 0.6 0.7

Don't Know.................................................. 4.5 1.7 1.0 0.7 0.5 0.6

Number of Households With --

Housing 

Units 

(millions)

1

 Member

2

 Members

3

Air Conditioning Characteristics Members

 Million U.S. Housing Units

5 or More 

Members

4

 Members

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Table HC6.6 Air Conditioning Characteristics by Number of Household Members, 2005

Number of Households With --

Housing 

Units 

(millions)

1

 Member

2

 Members

3

Air Conditioning Characteristics Members

 Million U.S. Housing Units

5 or More 

Members

4

 Members

Used by Two or More Housing Units

Less than 2 Years....................................... Q Q Q N N N

2 to 4 Years................................................. Q N N Q Q N

5 to 9 Years................................................. 0.3 QQQQN

10 to 19 Years............................................. 0.3 Q Q Q N Q

20 Years or More......................................... 0.3 QQQQN

Don't Know.................................................. 0.7 Q 0.3 Q Q Q

Household Pays for Electricity

for Central Air-Conditioning

Yes................................................................. 63.6 14.3 22.0 10.5 9.7 7.1

No................................................................... 2.3 1.0 0.6 Q 0.2 Q

Window/Wall Unit Air-Conditioning.................... 28.9 9.5 7.4 5.3 3.7 2.9

Frequency Most-Used Unit Used

Never.............................................................. 0.6 Q 0.2 Q Q Q

Only a Few Times When Needed................... 12.1 4.6 3.1 1.7 1.5 1.1

Quite a Bit....................................................... 7.5 2.4 1.9 1.6 0.8 0.8

All Summer..................................................... 8.6 2.3 2.1 1.9 1.3 0.9

Age of Most-Used Unit

Less than 2 Years........................................... 6.4 1.6 1.8 1.2 0.9 0.9

2 to 4 Years.................................................... 7.8 2.4 2.2 1.3 1.1 0.9

5 to 9 Years.................................................... 7.0 2.2 1.8 1.6 0.9 0.5

10 to 19 Years................................................ 3.7 1.5 0.9 0.7 0.3 0.3

20 Years or More............................................ 2.1 1.2 0.3 0.2 0.2 Q

Don't Know...................................................... 1.8 0.5 0.4 0.3 0.2 0.3

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes................................................................. 26.1 8.2 6.8 5.0 3.4 2.7

No................................................................... 2.2 1.1 0.4 0.3 0.3 Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Total............................................................... 111.1 26.7 28.8 20.6 13.1 22.0 16.6 38.6

Do Not Have Cooling Equipment................. 17.8 5.3 4.7 2.8 1.9 3.1 3.6 7.5

Have Coolling Equipment............................. 93.3 21.5 24.1 17.8 11.2 18.8 13.0 31.1

Use Cooling Equipment............................... 91.4 21.0 23.5 17.4 11.0 18.6 12.6 30.3

Have Equipment But Do Not Use it............. 1.9 0.5 0.6 0.4 Q Q 0.5 0.8

Air-Conditioning Equipment1, 2

Central System............................................ 65.9 11.0 16.5 13.5 8.7 16.1 6.4 17.2

Without a Heat Pump.............................. 53.5 9.4 13.6 10.7 7.1 12.7 5.4 14.5

With a Heat Pump................................... 12.3 1.7 2.8 2.8 1.6 3.4 1.0 2.7

Window/Wall Units...................................... 28.9 10.5 8.1 4.5 2.7 3.1 6.7 14.1

1 Unit....................................................... 14.5 5.8 4.3 2.0 1.1 1.3 3.4 7.4

2 Units..................................................... 9.1 3.2 2.4 1.5 0.9 1.1 2.3 4.4

3 or More Units........................................ 5.4 1.6 1.4 1.0 0.7 0.8 1.1 2.4

Central Air-Conditioning............................... 65.9 11.0 16.5 13.5 8.7 16.1 6.4 17.2

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit.................................... 64.2 10.5 15.8 13.2 8.5 16.0 6.1 16.4

Two or More Housing Units...................... 1.7 0.5 0.6 Q Q Q 0.3 0.8

Do Not Have Central A/C Equipment....... 45.2 15.7 12.3 7.0 4.4 5.8 10.2 21.4

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None........................................................ 1.4 0.4 0.4 0.3 Q Q 0.5 0.6

1.............................................................. 0.7 Q Q Q Q QQ Q

2.............................................................. 2.1 0.5 0.8 0.5 Q Q 0.4 0.7

3.............................................................. 7.5 2.2 1.7 1.4 0.9 1.3 1.3 2.5

4.............................................................. 7.9 2.2 2.5 1.2 0.6 1.3 1.2 3.1

5 or More................................................. 46.3 5.5 11.0 9.9 6.8 13.2 2.9 10.1

Proportion of Rooms Air-Conditioned

None........................................................ 1.4 0.4 0.4 0.3 Q Q 0.5 0.6

Some, But Not All of the Rooms.............. 8.4 1.4 1.9 1.6 1.0 2.5 0.9 1.9

All of the Rooms...................................... 56.1 9.2 14.2 11.6 7.5 13.5 5.0 14.7

Frequency of Central Air-Conditioner Use

Never....................................................... 1.4 0.4 0.4 0.3 Q Q 0.5 0.6

Only a Few Times When Needed............ 11.4 2.4 2.9 2.0 1.5 2.6 1.2 3.6

Quite a Bit................................................ 12.6 1.8 3.4 2.3 2.0 3.1 1.1 3.1

All Summer.............................................. 40.5 6.5 9.8 8.9 5.0 10.3 3.6 9.9

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years................................ 9.0 1.3 2.0 1.6 1.2 2.9 0.8 2.1

2 to 4 Years......................................... 11.0 1.7 2.6 2.6 1.4 2.7 1.0 2.7

5 to 9 Years......................................... 16.3 2.0 4.2 3.1 2.5 4.4 1.0 3.4

10 to 19 Years...................................... 16.8 2.3 3.9 3.8 2.4 4.3 1.3 3.8

20 Years or More................................. 6.5 1.7 1.8 1.4 0.6 1.1 1.0 2.3

Don't Know........................................... 4.5 1.5 1.4 0.7 0.3 0.6 0.9 2.2

 Million U.S. Housing Units

Table HC7.6 Air Conditioning Characteristics by Household Income, 2005

Below 

Poverty 

Line

Eligible for 

Federal 

Assistance $80,000 or 1

More

$60,000 to 

$79,999

2005 Household Income

Housing 

Units 

(millions)

Less than 

$20,000

$20,000 to 

$39,999

$40,000 to 

Air Conditioning Characteristics $59,999

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Table HC7.6 Air Conditioning Characteristics by Household Income, 2005

Below 

Poverty 

Line

Eligible for 

Federal 

Assistance $80,000 or 1

More

$60,000 to 

$79,999

2005 Household Income

Housing 

Units 

(millions)

Less than 

$20,000

$20,000 to 

$39,999

$40,000 to 

Air Conditioning Characteristics $59,999

Used by Two or More Housing Units

Less than 2 Years................................ Q Q N Q N N Q Q

2 to 4 Years......................................... Q N Q Q N N N Q

5 to 9 Years......................................... 0.3 Q Q Q Q QQ Q

10 to 19 Years...................................... 0.3 Q Q N Q Q Q Q

20 Years or More................................. 0.3 Q Q Q Q NQ Q

Don't Know........................................... 0.7 Q Q Q Q QQ Q

Household Pays for Electricity

for Central Air-Conditioning

Yes.......................................................... 63.6 10.0 15.8 13.3 8.4 16.0 5.8 16.0

No............................................................ 2.3 1.0 0.6 Q Q Q 0.6 1.2

Window/Wall Unit Air-Conditioning............. 28.9 10.5 8.1 4.5 2.7 3.1 6.7 14.1

Frequency Most-Used Unit Used

Never....................................................... 0.6 Q Q Q Q Q Q 0.2

Only a Few Times When Needed............ 12.1 4.2 3.2 1.9 1.4 1.4 2.5 5.8

Quite a Bit................................................ 7.5 2.4 2.4 1.2 0.8 0.8 1.4 3.3

All Summer.............................................. 8.6 3.7 2.3 1.2 0.6 0.8 2.7 4.8

Age of Most-Used Unit

Less than 2 Years.................................... 6.4 2.1 1.8 1.0 0.7 0.9 1.4 3.0

2 to 4 Years............................................. 7.8 2.6 2.2 1.4 0.8 0.8 1.7 3.8

5 to 9 Years............................................. 7.0 2.5 2.0 1.2 0.6 0.8 1.5 3.2

10 to 19 Years......................................... 3.7 1.6 1.0 0.3 0.4 0.5 1.0 1.9

20 Years or More..................................... 2.1 0.9 0.5 0.4 Q Q 0.5 1.1

Don't Know.............................................. 1.8 0.9 0.6 Q Q Q 0.6 1.2

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes.......................................................... 26.1 8.8 7.5 4.2 2.7 2.9 5.6 12.2

No............................................................ 2.2 1.5 0.4 Q Q Q 1.1 1.7

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for central airconditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Total.............................................................................. 111.1 47.1 19.0 22.7 22.3

Do Not Have Cooling Equipment................................ 17.8 8.5 2.7 2.6 4.0

Have Coolling Equipment............................................ 93.3 38.6 16.2 20.1 18.4

Use Cooling Equipment.............................................. 91.4 37.8 15.9 19.8 18.0

Have Equipment But Do Not Use it............................. 1.9 0.9 0.3 0.3 0.4

Air-Conditioning Equipment1, 2

Central System........................................................... 65.9 25.8 10.9 16.6 12.5

Without a Heat Pump.............................................. 53.5 21.2 9.7 13.7 8.9

With a Heat Pump................................................... 12.3 4.6 1.2 2.8 3.6

Window/Wall Units..................................................... 28.9 13.4 5.6 3.9 6.1

1 Unit...................................................................... 14.5 6.8 2.3 2.0 3.3

2 Units.................................................................... 9.1 4.1 1.9 1.2 1.9

3 or More Units....................................................... 5.4 2.4 1.4 0.7 0.9

Central Air-Conditioning.............................................. 65.9 25.8 10.9 16.6 12.5

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit.................................................... 64.2 24.9 10.7 16.1 12.5

Two or More Housing Units..................................... 1.7 0.9 Q 0.5 Q

Do Not Have Central A/C Equipment...................... 45.2 21.3 8.0 6.1 9.8

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None....................................................................... 1.4 0.7 Q Q Q

1............................................................................. 0.7 0.3 Q Q Q

2............................................................................. 2.1 0.7 0.4 0.5 0.4

3............................................................................. 7.5 3.7 1.2 1.6 1.1

4............................................................................. 7.9 3.6 1.6 1.4 1.2

5 or More................................................................ 46.3 16.8 7.4 12.6 9.6

Proportion of Rooms Air-Conditioned

None....................................................................... 1.4 0.7 Q Q Q

Some, But Not All of the Rooms............................. 8.4 3.0 1.3 2.4 1.7

All of the Rooms..................................................... 56.1 22.2 9.5 13.9 10.5

Frequency of Central Air-Conditioner Use

Never...................................................................... 1.4 0.7 Q Q Q

Only a Few Times When Needed........................... 11.4 4.9 1.8 2.9 1.8

Quite a Bit............................................................... 12.6 4.9 2.1 3.1 2.5

All Summer............................................................. 40.5 15.3 6.8 10.3 8.0

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years............................................... 9.0 3.4 1.4 2.4 1.8

2 to 4 Years......................................................... 11.0 4.0 2.1 2.8 2.2

5 to 9 Years......................................................... 16.3 5.9 2.7 3.8 3.9

10 to 19 Years..................................................... 16.8 6.1 2.6 4.9 3.2

20 Years or More................................................. 6.5 3.1 1.2 1.4 0.8

Don't Know.......................................................... 4.5 2.5 0.7 0.8 0.4

 Million U.S. Housing Units

Table HC8.6 Air Conditioning Characteristics by Urban/Rural Location, 2005

Housing

Units 

Housing Unit Characteristics (millions)

Urban/Rural Location

(as Self-Reported)

City Town Surburbs Rural

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Table HC8.6 Air Conditioning Characteristics by Urban/Rural Location, 2005

Housing

Units 

Housing Unit Characteristics (millions)

Urban/Rural Location

(as Self-Reported)

City Town Surburbs Rural

Used by Two or More Housing Units

Less than 2 Years............................................... Q Q N N N

2 to 4 Years......................................................... Q Q Q N N

5 to 9 Years......................................................... 0.3 QQQQ

10 to 19 Years..................................................... 0.3 QQQQ

20 Years or More................................................. 0.3 Q N Q N

Don't Know.......................................................... 0.7 0.4 Q Q N

Household Pays for Electricity

for Central Air-Conditioning

Yes......................................................................... 63.6 24.7 10.4 16.1 12.4

No........................................................................... 2.3 1.1 0.5 Q Q

Window/Wall Unit Air-Conditioning............................ 28.9 13.4 5.6 3.9 6.1

Frequency Most-Used Unit Used

Never...................................................................... 0.6 0.3 Q Q Q

Only a Few Times When Needed........................... 12.1 5.8 2.2 1.7 2.4

Quite a Bit............................................................... 7.5 3.2 1.7 1.1 1.6

All Summer............................................................. 8.6 4.1 1.5 1.0 2.0

Age of Most-Used Unit

Less than 2 Years................................................... 6.4 3.5 1.0 0.9 1.0

2 to 4 Years............................................................ 7.8 3.4 1.7 1.0 1.8

5 to 9 Years............................................................ 7.0 2.8 1.3 1.1 1.9

10 to 19 Years........................................................ 3.7 1.6 0.7 0.5 0.8

20 Years or More.................................................... 2.1 1.1 0.5 Q 0.3

Don't Know.............................................................. 1.8 1.0 0.4 Q 0.3

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes......................................................................... 26.1 11.6 5.1 3.6 5.8

No........................................................................... 2.2 1.4 0.4 Q Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was 

electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Table HC9.6 Air Conditioning Characteristics by Climate Zone, 2005

 Million U.S. Housing Units

Total......................................................................... 111.1 10.9 26.1 27.3 24.0 22.8

Do Not Have Cooling Equipment........................... 17.8 3.2 4.7 3.6 5.5 0.9

Have Coolling Equipment....................................... 93.3 7.7 21.4 23.7 18.5 21.9

Use Cooling Equipment......................................... 91.4 7.6 21.0 23.4 17.9 21.7

Have Equipment But Do Not Use it........................ 1.9 Q 0.4 0.4 0.6 0.3

Air-Conditioning Equipment2, 3

Central System...................................................... 65.9 4.8 12.3 15.1 14.9 18.7

Without a Heat Pump......................................... 53.5 4.7 11.5 11.6 12.3 13.6

With a Heat Pump.............................................. 12.3 Q 0.9 3.5 2.7 5.2

Window/Wall Units................................................. 28.9 3.1 9.3 8.8 4.0 3.7

1 Unit................................................................. 14.5 2.1 5.0 3.6 2.4 1.4

2 Units................................................................ 9.1 0.7 2.9 3.3 1.0 1.2

3 or More Units.................................................. 5.4 0.3 1.5 1.9 0.6 1.1

Central Air-Conditioning......................................... 65.9 4.8 12.3 15.1 14.9 18.7

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit............................................... 64.2 4.7 11.9 14.5 14.7 18.3

Two or More Housing Units................................ 1.7 Q 0.4 Q Q 0.4

Do Not Have Central A/C Equipment................. 45.2 6.2 13.7 12.2 9.0 4.1

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None.................................................................. 1.4 Q 0.3 Q 0.6 0.2

1......................................................................... 0.7 N Q Q Q Q

2......................................................................... 2.1 Q 0.5 0.4 0.5 0.5

3......................................................................... 7.5 0.4 1.4 1.3 2.0 2.4

4......................................................................... 7.9 0.4 1.2 1.8 1.9 2.6

5 or More............................................................ 46.3 3.7 8.9 11.2 9.9 12.7

Proportion of Rooms Air-Conditioned

None.................................................................. 1.4 Q 0.3 Q 0.6 0.2

Some, But Not All of the Rooms........................ 8.4 0.7 1.8 1.6 2.4 1.9

All of the Rooms................................................. 56.1 4.0 10.2 13.2 12.0 16.6

Frequency of Central Air-Conditioner Use

Never................................................................. 1.4 Q 0.3 Q 0.6 0.2

Only a Few Times When Needed....................... 11.4 1.7 3.1 2.3 3.5 0.9

Quite a Bit.......................................................... 12.6 1.6 3.3 2.8 2.9 2.0

All Summer........................................................ 40.5 1.4 5.6 9.8 8.0 15.6

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years.......................................... 9.0 0.7 1.7 2.0 1.9 2.8

2 to 4 Years.................................................... 11.0 0.8 2.2 2.2 2.2 3.7

5 to 9 Years.................................................... 16.3 1.4 3.3 3.4 3.8 4.4

10 to 19 Years................................................ 16.8 1.4 2.9 4.2 4.4 3.9

20 Years or More............................................ 6.5 0.3 0.9 1.7 1.6 2.0

Don't Know..................................................... 4.5 Q 1.0 0.9 0.8 1.5

Climate Zone1

2,000 CDD 

or More

and Less 

than 4,000 

Air Conditioning Characteristics HDD

Less than 2,000 CDD and --

Less than 

4,000 HDD

Greater than 

7,000 HDD

5,500 to 

7,000 HDD

4,000 to 

5,499 HDD

Housing 

Units 

(millions)

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Table HC9.6 Air Conditioning Characteristics by Climate Zone, 2005

 Million U.S. Housing Units

Climate Zone1

2,000 CDD 

or More

and Less 

than 4,000 

Air Conditioning Characteristics HDD

Less than 2,000 CDD and --

Less than 

4,000 HDD

Greater than 

7,000 HDD

5,500 to 

7,000 HDD

4,000 to 

5,499 HDD

Housing 

Units 

(millions)

Used by Two or More Housing Units

Less than 2 Years.......................................... Q Q N N N Q

2 to 4 Years.................................................... Q N N Q N Q

5 to 9 Years.................................................... 0.3 Q Q Q Q N

10 to 19 Years................................................ 0.3 Q Q Q Q Q

20 Years or More............................................ 0.3 N Q Q Q Q

Don't Know..................................................... 0.7 N Q Q Q Q

Household Pays for Electricity

for Central Air-Conditioning

Yes.................................................................... 63.6 4.7 12.0 14.2 14.5 18.2

No...................................................................... 2.3 Q Q 0.9 0.4 0.5

Window/Wall Unit Air-Conditioning....................... 28.9 3.1 9.3 8.8 4.0 3.7

Frequency Most-Used Unit Used

Never................................................................. 0.6 Q Q Q Q Q

Only a Few Times When Needed....................... 12.1 1.5 4.2 3.8 1.7 0.9

Quite a Bit.......................................................... 7.5 1.0 2.6 2.1 0.9 0.9

All Summer........................................................ 8.6 0.4 2.4 2.7 1.3 1.7

Age of Most-Used Unit

Less than 2 Years.............................................. 6.4 0.5 2.1 2.1 1.0 0.8

2 to 4 Years....................................................... 7.8 0.9 2.6 2.3 0.8 1.1

5 to 9 Years....................................................... 7.0 0.7 2.1 2.3 1.0 1.0

10 to 19 Years.................................................... 3.7 0.3 1.2 1.1 0.6 0.5

20 Years or More............................................... 2.1 0.2 0.7 0.5 0.4 Q

Don't Know......................................................... 1.8 0.3 0.6 0.6 0.2 Q

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes.................................................................... 26.1 2.7 8.5 7.8 3.8 3.2

No...................................................................... 2.2 Q 0.7 0.8 Q 0.3

 1. One of five climatically distinct areas, determined according to the 30-year average (1971-2000) of the annual heating and cooling 

degree-days. A household is assigned to a climate zone according to the 30-year average annual degree-days for an appropriate nearby 

weather station.

 2. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 3. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Total.............................................................................. 111.1 20.6 25.6 40.7 24.2

Do Not Have Cooling Equipment................................ 17.8 4.0 2.1 1.4 10.3

Have Coolling Equipment............................................ 93.3 16.5 23.5 39.3 13.9

Use Cooling Equipment.............................................. 91.4 16.3 23.4 38.9 12.9

Have Equipment But Do Not Use it............................. 1.9 0.3 Q 0.5 1.0

Air-Conditioning Equipment1, 2

Central System........................................................... 65.9 6.0 17.3 32.1 10.5

Without a Heat Pump.............................................. 53.5 5.5 16.2 23.2 8.7

With a Heat Pump................................................... 12.3 0.5 1.1 9.0 1.7

Window/Wall Units..................................................... 28.9 10.7 6.6 8.0 3.6

1 Unit...................................................................... 14.5 4.3 4.1 3.1 2.9

2 Units.................................................................... 9.1 4.1 1.8 2.8 0.4

3 or More Units....................................................... 5.4 2.3 0.7 2.1 0.3

Central Air-Conditioning.............................................. 65.9 6.0 17.3 32.1 10.5

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit.................................................... 64.2 5.8 16.9 31.1 10.3

Two or More Housing Units..................................... 1.7 Q 0.4 1.0 Q

Do Not Have Central A/C Equipment...................... 45.2 14.6 8.3 8.6 13.7

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None....................................................................... 1.4 Q Q 0.4 0.8

1............................................................................. 0.7 Q Q 0.4 Q

2............................................................................. 2.1 0.3 0.4 0.8 0.6

3............................................................................. 7.5 0.3 1.9 3.9 1.4

4............................................................................. 7.9 0.7 1.5 4.6 1.0

5 or More................................................................ 46.3 4.5 13.2 22.0 6.7

Proportion of Rooms Air-Conditioned

None....................................................................... 1.4 Q Q 0.4 0.8

Some, But Not All of the Rooms............................. 8.4 0.7 2.3 3.6 1.9

All of the Rooms..................................................... 56.1 5.2 14.9 28.2 7.8

Frequency of Central Air-Conditioner Use

Never...................................................................... 1.4 Q Q 0.4 0.8

Only a Few Times When Needed........................... 11.4 1.6 3.9 2.5 3.4

Quite a Bit............................................................... 12.6 1.2 4.5 4.5 2.4

All Summer............................................................. 40.5 3.0 8.8 24.8 3.9

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years............................................... 9.0 1.0 2.0 4.3 1.8

2 to 4 Years......................................................... 11.0 0.9 2.7 5.7 1.7

5 to 9 Years......................................................... 16.3 1.3 4.7 8.0 2.3

10 to 19 Years..................................................... 16.8 1.6 4.7 7.8 2.7

20 Years or More................................................. 6.5 0.7 1.5 3.1 1.3

Don't Know.......................................................... 4.5 0.3 1.3 2.3 0.6

Housing

Units 

(millions)

 Million U.S. Housing Units

Table HC10.6 Air Conditioning Characteristics by U.S. Census Region, 2005

Air Conditioning Characteristics

U.S. Census Region

Northeast Midwest South West

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Housing

Units 

(millions)

 Million U.S. Housing Units

Table HC10.6 Air Conditioning Characteristics by U.S. Census Region, 2005

Air Conditioning Characteristics

U.S. Census Region

Northeast Midwest South West

Used by Two or More Housing Units

Less than 2 Years............................................... Q N Q Q N

2 to 4 Years......................................................... Q Q N Q N

5 to 9 Years......................................................... 0.3 Q Q Q N

10 to 19 Years..................................................... 0.3 N Q Q Q

20 Years or More................................................. 0.3 QQQQ

Don't Know.......................................................... 0.7 QQQQ

Household Pays for Electricity

for Central Air-Conditioning

Yes......................................................................... 63.6 5.7 16.9 30.8 10.2

No........................................................................... 2.3 Q 0.4 1.4 0.3

Window/Wall Unit Air-Conditioning............................ 28.9 10.7 6.6 8.0 3.6

Frequency Most-Used Unit Used

Never...................................................................... 0.6 QQQQ

Only a Few Times When Needed........................... 12.1 4.9 3.1 2.1 2.0

Quite a Bit............................................................... 7.5 3.0 1.6 2.2 0.7

All Summer............................................................. 8.6 2.6 1.8 3.6 0.7

Age of Most-Used Unit

Less than 2 Years................................................... 6.4 2.5 1.3 1.7 0.9

2 to 4 Years............................................................ 7.8 3.1 1.7 2.1 0.9

5 to 9 Years............................................................ 7.0 2.7 1.5 2.1 0.7

10 to 19 Years........................................................ 3.7 1.4 0.8 1.1 0.4

20 Years or More.................................................... 2.1 0.7 0.5 0.5 0.4

Don't Know.............................................................. 1.8 0.3 0.7 0.4 0.3

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes......................................................................... 26.1 9.6 6.0 7.4 3.1

No........................................................................... 2.2 1.0 0.5 0.4 0.3

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was 

electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Total........................................................................... 111.1 20.6 15.1 5.5

Do Not Have Cooling Equipment............................. 17.8 4.0 2.4 1.7

Have Coolling Equipment......................................... 93.3 16.5 12.8 3.8

Use Cooling Equipment........................................... 91.4 16.3 12.6 3.7

Have Equipment But Do Not Use it.......................... 1.9 0.3 Q Q

Air-Conditioning Equipment1, 2

Central System........................................................ 65.9 6.0 5.2 0.8

Without a Heat Pump........................................... 53.5 5.5 4.8 0.7

With a Heat Pump............................................... 12.3 0.5 0.4 Q

Window/Wall Units.................................................. 28.9 10.7 7.6 3.1

1 Unit................................................................... 14.5 4.3 2.9 1.4

2 Units................................................................. 9.1 4.1 3.1 1.1

3 or More Units.................................................... 5.4 2.3 1.7 0.6

Central Air-Conditioning........................................... 65.9 6.0 5.2 0.8

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit................................................ 64.2 5.8 5.1 0.7

Two or More Housing Units.................................. 1.7 Q Q Q

Do Not Have Central A/C Equipment................... 45.2 14.6 9.9 4.7

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None.................................................................... 1.4 Q Q Q

1.......................................................................... 0.7 Q Q N

2.......................................................................... 2.1 0.3 0.3 Q

3.......................................................................... 7.5 0.3 0.3 Q

4.......................................................................... 7.9 0.7 Q 0.2

5 or More............................................................. 46.3 4.5 3.9 0.5

Proportion of Rooms Air-Conditioned

None.................................................................... 1.4 Q Q Q

Some, But Not All of the Rooms.......................... 8.4 0.7 0.6 Q

All of the Rooms.................................................. 56.1 5.2 4.5 0.6

Frequency of Central Air-Conditioner Use

Never................................................................... 1.4 Q Q Q

Only a Few Times When Needed........................ 11.4 1.6 1.4 0.3

Quite a Bit............................................................ 12.6 1.2 1.1 0.1

All Summer.......................................................... 40.5 3.0 2.6 0.3

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years............................................ 9.0 1.0 0.9 Q

2 to 4 Years...................................................... 11.0 0.9 0.8 Q

5 to 9 Years...................................................... 16.3 1.3 1.1 0.2

10 to 19 Years.................................................. 16.8 1.6 1.4 0.2

20 Years or More............................................. 6.5 0.7 0.7 Q

Don't Know....................................................... 4.5 0.3 Q Q

 Million U.S. Housing Units

Table HC11.6 Air Conditioning Characteristics by Northeast Census Region, 2005

Air Conditioning Characteristics Middle Atlantic New England

Northeast Census Region

U.S.

Housing

Units

(millions)

Census Division

Total

Northeast

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Table HC11.6 Air Conditioning Characteristics by Northeast Census Region, 2005

Air Conditioning Characteristics Middle Atlantic New England

Northeast Census Region

U.S.

Housing

Units

(millions)

Census Division

Total

Northeast

Used by Two or More Housing Units

Less than 2 Years............................................ Q N N N

2 to 4 Years...................................................... Q Q Q N

5 to 9 Years...................................................... 0.3 Q Q Q

10 to 19 Years.................................................. 0.3 N N N

20 Years or More............................................. 0.3 Q Q N

Don't Know....................................................... 0.7 Q N Q

Household Pays for Electricity

for Central Air-Conditioning

Yes...................................................................... 63.6 5.7 5.0 0.8

No........................................................................ 2.3 Q Q N

Window/Wall Unit Air-Conditioning......................... 28.9 10.7 7.6 3.1

Frequency Most-Used Unit Used

Never................................................................... 0.6 Q Q Q

Only a Few Times When Needed........................ 12.1 4.9 3.4 1.5

Quite a Bit............................................................ 7.5 3.0 2.2 0.8

All Summer.......................................................... 8.6 2.6 1.9 0.7

Age of Most-Used Unit

Less than 2 Years................................................ 6.4 2.5 1.7 0.8

2 to 4 Years......................................................... 7.8 3.1 2.2 1.0

5 to 9 Years......................................................... 7.0 2.7 2.1 0.6

10 to 19 Years..................................................... 3.7 1.4 1.0 0.4

20 Years or More................................................. 2.1 0.7 0.5 0.2

Don't Know.......................................................... 1.8 0.3 0.2 0.1

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes...................................................................... 26.1 9.6 6.7 2.8

No........................................................................ 2.2 1.0 0.8 0.2

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Total........................................................................... 111.1 25.6 17.7 7.9

Do Not Have Cooling Equipment............................. 17.8 2.1 1.8 0.3

Have Coolling Equipment......................................... 93.3 23.5 16.0 7.5

Use Cooling Equipment........................................... 91.4 23.4 15.9 7.5

Have Equipment But Do Not Use it.......................... 1.9 Q Q Q

Air-Conditioning Equipment1, 2

Central System........................................................ 65.9 17.3 11.3 6.0

Without a Heat Pump........................................... 53.5 16.2 10.6 5.6

With a Heat Pump............................................... 12.3 1.1 0.8 0.4

Window/Wall Units.................................................. 28.9 6.6 4.9 1.7

1 Unit................................................................... 14.5 4.1 2.9 1.2

2 Units................................................................. 9.1 1.8 1.4 0.3

3 or More Units.................................................... 5.4 0.7 0.5 Q

Central Air-Conditioning........................................... 65.9 17.3 11.3 6.0

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit................................................ 64.2 16.9 11.0 5.9

Two or More Housing Units.................................. 1.7 0.4 Q Q

Do Not Have Central A/C Equipment................... 45.2 8.3 6.4 1.9

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None.................................................................... 1.4 Q Q Q

1.......................................................................... 0.7 Q Q N

2.......................................................................... 2.1 0.4 0.3 Q

3.......................................................................... 7.5 1.9 1.3 0.6

4.......................................................................... 7.9 1.5 1.0 0.5

5 or More............................................................. 46.3 13.2 8.6 4.6

Proportion of Rooms Air-Conditioned

None.................................................................... 1.4 Q Q Q

Some, But Not All of the Rooms.......................... 8.4 2.3 1.6 0.7

All of the Rooms.................................................. 56.1 14.9 9.7 5.2

Frequency of Central Air-Conditioner Use

Never................................................................... 1.4 Q Q Q

Only a Few Times When Needed........................ 11.4 3.9 2.8 1.1

Quite a Bit............................................................ 12.6 4.5 3.1 1.4

All Summer.......................................................... 40.5 8.8 5.4 3.4

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years............................................ 9.0 2.0 1.3 0.7

2 to 4 Years...................................................... 11.0 2.7 1.7 1.0

5 to 9 Years...................................................... 16.3 4.7 3.3 1.4

10 to 19 Years.................................................. 16.8 4.7 3.1 1.7

20 Years or More............................................. 6.5 1.5 1.0 0.5

Don't Know....................................................... 4.5 1.3 0.7 0.6

Used by Two or More Housing Units

 Million U.S. Housing Units

Table HC12.6 Air Conditioning Characteristics by Midwest Census Region, 2005

Air Conditioning Characteristics East North Central West North Central

Midwest Census Region

U.S.

Housing

Units

(millions)

Census Division

Total

Midwest

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Table HC12.6 Air Conditioning Characteristics by Midwest Census Region, 2005

Air Conditioning Characteristics East North Central West North Central

Midwest Census Region

U.S.

Housing

Units

(millions)

Census Division

Total

Midwest

Less than 2 Years............................................ Q Q N Q

2 to 4 Years...................................................... Q N N N

5 to 9 Years...................................................... 0.3 Q Q Q

10 to 19 Years.................................................. 0.3 Q Q N

20 Years or More............................................. 0.3 Q Q N

Don't Know....................................................... 0.7 Q Q Q

Household Pays for Electricity

for Central Air-Conditioning

Yes...................................................................... 63.6 16.9 11.0 5.8

No........................................................................ 2.3 0.4 Q Q

Window/Wall Unit Air-Conditioning......................... 28.9 6.6 4.9 1.7

Frequency Most-Used Unit Used

Never................................................................... 0.6 Q Q N

Only a Few Times When Needed........................ 12.1 3.1 2.4 0.7

Quite a Bit............................................................ 7.5 1.6 1.2 0.4

All Summer.......................................................... 8.6 1.8 1.2 0.6

Age of Most-Used Unit

Less than 2 Years................................................ 6.4 1.3 0.9 0.5

2 to 4 Years......................................................... 7.8 1.7 1.3 0.3

5 to 9 Years......................................................... 7.0 1.5 1.2 0.4

10 to 19 Years..................................................... 3.7 0.8 0.7 Q

20 Years or More................................................. 2.1 0.5 0.4 Q

Don't Know.......................................................... 1.8 0.7 0.5 0.2

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes...................................................................... 26.1 6.0 4.5 1.5

No........................................................................ 2.2 0.5 0.3 Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Total.............................................................................. 111.1 40.7 21.7 6.9 12.1

Do Not Have Cooling Equipment................................ 17.8 1.4 0.8 0.2 0.3

Have Coolling Equipment............................................ 93.3 39.3 20.9 6.7 11.8

Use Cooling Equipment.............................................. 91.4 38.9 20.7 6.6 11.7

Have Equipment But Do Not Use it............................. 1.9 0.5 Q Q Q

Air-Conditioning Equipment1, 2

Central System........................................................... 65.9 32.1 17.6 5.2 9.3

Without a Heat Pump.............................................. 53.5 23.2 10.9 3.8 8.4

With a Heat Pump................................................... 12.3 9.0 6.7 1.4 0.9

Window/Wall Units..................................................... 28.9 8.0 3.4 1.7 2.9

1 Unit...................................................................... 14.5 3.1 1.4 0.8 0.9

2 Units.................................................................... 9.1 2.8 1.1 0.7 1.0

3 or More Units....................................................... 5.4 2.1 0.9 0.2 1.0

Central Air-Conditioning.............................................. 65.9 32.1 17.6 5.2 9.3

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit.................................................... 64.2 31.1 16.9 5.2 9.1

Two or More Housing Units..................................... 1.7 1.0 0.7 Q Q

Do Not Have Central A/C Equipment...................... 45.2 8.6 4.1 1.7 2.8

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None....................................................................... 1.4 0.4 Q Q Q

1............................................................................. 0.7 0.4 Q N Q

2............................................................................. 2.1 0.8 Q Q 0.4

3............................................................................. 7.5 3.9 2.1 0.5 1.3

4............................................................................. 7.9 4.6 2.8 0.9 0.9

5 or More................................................................ 46.3 22.0 12.0 3.5 6.5

Proportion of Rooms Air-Conditioned

None....................................................................... 1.4 0.4 Q Q Q

Some, But Not All of the Rooms............................. 8.4 3.6 1.8 0.7 1.0

All of the Rooms..................................................... 56.1 28.2 15.6 4.4 8.2

Frequency of Central Air-Conditioner Use

Never...................................................................... 1.4 0.4 Q Q Q

Only a Few Times When Needed........................... 11.4 2.5 1.6 0.4 0.5

Quite a Bit............................................................... 12.6 4.5 2.5 0.8 1.2

All Summer............................................................. 40.5 24.8 13.4 3.8 7.6

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years............................................... 9.0 4.3 2.2 0.7 1.3

2 to 4 Years......................................................... 11.0 5.7 2.8 0.9 2.0

5 to 9 Years......................................................... 16.3 8.0 5.0 1.4 1.6

10 to 19 Years..................................................... 16.8 7.8 4.5 1.4 2.0

20 Years or More................................................. 6.5 3.1 1.3 0.5 1.3

Don't Know.......................................................... 4.5 2.3 1.0 0.3 0.9

Total 

South

 Million U.S. Housing Units

Table HC13.6 Air Conditioning Characteristics by South Census Region, 2005

Air Conditioning Characteristics South Atlantic East South 

Central

West South 

Central

South Census Region

U.S.

Housing

Units

(millions)

Census Division

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Total 

South

 Million U.S. Housing Units

Table HC13.6 Air Conditioning Characteristics by South Census Region, 2005

Air Conditioning Characteristics South Atlantic East South 

Central

West South 

Central

South Census Region

U.S.

Housing

Units

(millions)

Census Division

Used by Two or More Housing Units

Less than 2 Years............................................... Q Q Q N N

2 to 4 Years......................................................... Q Q N N Q

5 to 9 Years......................................................... 0.3 Q Q N N

10 to 19 Years..................................................... 0.3 QQQQ

20 Years or More................................................. 0.3 Q Q N Q

Don't Know.......................................................... 0.7 Q Q N Q

Household Pays for Electricity

for Central Air-Conditioning

Yes......................................................................... 63.6 30.8 16.7 5.1 9.0

No........................................................................... 2.3 1.4 0.9 Q 0.4

Window/Wall Unit Air-Conditioning............................ 28.9 8.0 3.4 1.7 2.9

Frequency Most-Used Unit Used

Never...................................................................... 0.6 QQQQ

Only a Few Times When Needed........................... 12.1 2.1 1.0 0.5 0.6

Quite a Bit............................................................... 7.5 2.2 1.1 0.5 0.6

All Summer............................................................. 8.6 3.6 1.2 0.8 1.5

Age of Most-Used Unit

Less than 2 Years................................................... 6.4 1.7 0.7 0.3 0.6

2 to 4 Years............................................................ 7.8 2.1 1.0 Q 0.9

5 to 9 Years............................................................ 7.0 2.1 0.7 0.6 0.8

10 to 19 Years........................................................ 3.7 1.1 0.4 0.4 0.3

20 Years or More.................................................... 2.1 0.5 Q Q Q

Don't Know.............................................................. 1.8 0.4 Q Q Q

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes......................................................................... 26.1 7.4 3.2 1.6 2.6

No........................................................................... 2.2 0.4 Q Q Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was 

electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Total........................................................................... 111.1 24.2 7.6 16.6

Do Not Have Cooling Equipment............................. 17.8 10.3 3.1 7.3

Have Coolling Equipment......................................... 93.3 13.9 4.5 9.4

Use Cooling Equipment........................................... 91.4 12.9 4.3 8.5

Have Equipment But Do Not Use it.......................... 1.9 1.0 Q 0.8

Air-Conditioning Equipment1, 2

Central System........................................................ 65.9 10.5 3.9 6.5

Without a Heat Pump........................................... 53.5 8.7 3.2 5.5

With a Heat Pump............................................... 12.3 1.7 0.7 1.0

Window/Wall Units.................................................. 28.9 3.6 0.6 3.0

1 Unit................................................................... 14.5 2.9 0.5 2.4

2 Units................................................................. 9.1 0.4 Q 0.4

3 or More Units.................................................... 5.4 0.3 Q Q

Central Air-Conditioning........................................... 65.9 10.5 3.9 6.5

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit................................................ 64.2 10.3 3.9 6.4

Two or More Housing Units.................................. 1.7 Q N Q

Do Not Have Central A/C Equipment................... 45.2 13.7 3.6 10.1

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None.................................................................... 1.4 0.8 Q 0.7

1.......................................................................... 0.7 Q Q Q

2.......................................................................... 2.1 0.6 Q 0.4

3.......................................................................... 7.5 1.4 0.6 0.8

4.......................................................................... 7.9 1.0 0.5 0.5

5 or More............................................................. 46.3 6.7 2.5 4.1

Proportion of Rooms Air-Conditioned

None.................................................................... 1.4 0.8 Q 0.7

Some, But Not All of the Rooms.......................... 8.4 1.9 0.8 1.0

All of the Rooms.................................................. 56.1 7.8 3.0 4.8

Frequency of Central Air-Conditioner Use

Never................................................................... 1.4 0.8 Q 0.7

Only a Few Times When Needed........................ 11.4 3.4 0.7 2.7

Quite a Bit............................................................ 12.6 2.4 0.8 1.6

All Summer.......................................................... 40.5 3.9 2.4 1.5

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years............................................ 9.0 1.8 0.9 0.9

2 to 4 Years...................................................... 11.0 1.7 0.9 0.9

5 to 9 Years...................................................... 16.3 2.3 0.9 1.4

10 to 19 Years.................................................. 16.8 2.7 0.9 1.8

20 Years or More............................................. 6.5 1.3 0.3 1.0

Don't Know....................................................... 4.5 0.6 Q 0.5

 Million U.S. Housing Units

Table HC14.6 Air Conditioning Characteristics by West Census Region, 2005

Air Conditioning Characteristics Mountain Pacific

West Census Region

U.S.

Housing

Units

(millions)

Census Division

Total

West

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
 Million U.S. Housing Units

Table HC14.6 Air Conditioning Characteristics by West Census Region, 2005

Air Conditioning Characteristics Mountain Pacific

West Census Region

U.S.

Housing

Units

(millions)

Census Division

Total

West

Used by Two or More Housing Units

Less than 2 Years............................................ Q N N N

2 to 4 Years...................................................... Q N N N

5 to 9 Years...................................................... 0.3 N N N

10 to 19 Years.................................................. 0.3 Q N Q

20 Years or More............................................. 0.3 Q N Q

Don't Know....................................................... 0.7 Q N Q

Household Pays for Electricity

for Central Air-Conditioning

Yes...................................................................... 63.6 10.2 3.8 6.4

No........................................................................ 2.3 0.3 Q Q

Window/Wall Unit Air-Conditioning......................... 28.9 3.6 0.6 3.0

Frequency Most-Used Unit Used

Never................................................................... 0.6 Q Q Q

Only a Few Times When Needed........................ 12.1 2.0 0.2 1.8

Quite a Bit............................................................ 7.5 0.7 0.2 0.6

All Summer.......................................................... 8.6 0.7 Q 0.5

Age of Most-Used Unit

Less than 2 Years................................................ 6.4 0.9 Q 0.9

2 to 4 Years......................................................... 7.8 0.9 0.2 0.6

5 to 9 Years......................................................... 7.0 0.7 Q 0.6

10 to 19 Years..................................................... 3.7 0.4 Q 0.3

20 Years or More................................................. 2.1 0.4 Q 0.4

Don't Know.......................................................... 1.8 0.3 Q 0.3

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes...................................................................... 26.1 3.1 0.5 2.7

No........................................................................ 2.2 0.3 Q Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Table HC15.6 Air Conditioning Characteristics by Four Most Populated States, 2005

Total................................................................................. 111.1 7.1 7.0 8.0 12.1

Do Not Have Cooling Equipment................................... 17.8 1.8 Q Q 4.9

Have Coolling Equipment............................................... 93.3 5.3 7.0 7.8 7.2

Use Cooling Equipment................................................. 91.4 5.3 7.0 7.7 6.6

Have Equipment But Do Not Use it............................... 1.9 Q N Q 0.6

Air-Conditioning Equipment1, 2

Central System.............................................................. 65.9 1.1 6.4 6.4 5.4

Without a Heat Pump................................................ 53.5 1.1 3.5 5.7 4.9

With a Heat Pump..................................................... 12.3 Q 2.9 0.7 0.5

Window/Wall Units........................................................ 28.9 4.2 0.5 1.6 1.9

1 Unit......................................................................... 14.5 1.8 Q 0.6 1.5

2 Units....................................................................... 9.1 1.7 Q 0.6 Q

3 or More Units.......................................................... 5.4 0.7 Q 0.5 Q

Central Air-Conditioning................................................. 65.9 1.1 6.4 6.4 5.4

Housing Units Served by

Central Air-Conditiong Equipment

One Housing Unit...................................................... 64.2 1.1 6.2 6.2 5.3

Two or More Housing Units........................................ 1.7 QQQQ

Do Not Have Central A/C Equipment......................... 45.2 6.0 0.6 1.6 6.7

Number of Rooms Cooled by Central

Air-Conditioning in Summer 2005

None.......................................................................... 1.4 Q N Q 0.5

1................................................................................ 0.7 N Q Q Q

2................................................................................ 2.1 Q Q Q 0.4

3................................................................................ 7.5 Q 0.7 1.0 0.8

4................................................................................ 7.9 Q 1.4 0.5 0.4

5 or More................................................................... 46.3 0.8 4.2 4.5 3.4

Proportion of Rooms Air-Conditioned

None.......................................................................... 1.4 Q N Q 0.5

Some, But Not All of the Rooms................................ 8.4 Q 0.5 0.8 0.9

All of the Rooms........................................................ 56.1 0.9 5.9 5.5 4.0

Frequency of Central Air-Conditioner Use

Never......................................................................... 1.4 Q N Q 0.5

Only a Few Times When Needed.............................. 11.4 0.4 Q Q 2.4

Quite a Bit.................................................................. 12.6 0.3 0.5 0.9 1.3

All Summer................................................................ 40.5 0.4 5.7 5.2 1.2

Age of Central Air-Conditioner

Used by One Housing Unit

Less than 2 Years.................................................. 9.0 Q 0.9 1.0 0.7

2 to 4 Years........................................................... 11.0 Q 1.3 1.4 0.7

5 to 9 Years........................................................... 16.3 Q 1.9 1.0 1.0

10 to 19 Years........................................................ 16.8 0.3 1.2 1.2 1.6

20 Years or More................................................... 6.5 Q 0.5 0.8 0.9

Don't Know............................................................. 4.5 Q 0.4 0.7 0.4

Housing

Units 

(millions)

 Million U.S. Housing Units

Air Conditioning Characteristics

Four Most Populated States

New York Florida Texas California

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables
Table HC15.6 Air Conditioning Characteristics by Four Most Populated States, 2005

Housing

Units 

(millions)

 Million U.S. Housing Units

Air Conditioning Characteristics

Four Most Populated States

New York Florida Texas California

Used by Two or More Housing Units

Less than 2 Years.................................................. Q N Q N N

2 to 4 Years........................................................... Q N N Q N

5 to 9 Years........................................................... 0.3 Q N N N

10 to 19 Years........................................................ 0.3 N Q Q N

20 Years or More................................................... 0.3 N Q Q Q

Don't Know............................................................. 0.7 N Q Q Q

Household Pays for Electricity

for Central Air-Conditioning

Yes............................................................................ 63.6 1.1 6.2 6.2 5.3

No.............................................................................. 2.3 N Q Q Q

Window/Wall Unit Air-Conditioning............................... 28.9 4.2 0.5 1.6 1.9

Frequency Most-Used Unit Used

Never......................................................................... 0.6 Q N Q Q

Only a Few Times When Needed.............................. 12.1 1.9 Q 0.5 1.1

Quite a Bit.................................................................. 7.5 1.2 Q Q 0.4

All Summer................................................................ 8.6 1.0 Q 0.8 0.3

Age of Most-Used Unit

Less than 2 Years...................................................... 6.4 1.1 Q 0.3 0.6

2 to 4 Years............................................................... 7.8 1.3 Q 0.6 0.3

5 to 9 Years............................................................... 7.0 1.1 Q 0.5 0.3

10 to 19 Years........................................................... 3.7 0.6 Q Q Q

20 Years or More....................................................... 2.1 Q Q Q 0.3

Don't Know................................................................ 1.8 Q N Q Q

Household Pays for Electricity for

Window/Wall Air-Conditioners

Yes............................................................................ 26.1 3.6 0.5 1.3 1.7

No.............................................................................. 2.2 0.6 N Q Q

 1. In the 2005 RECS 1.5 million housing units reported having both central and window/wall air conditioners.

 2. The number of housing units using air-conditioning includes a small, undetermined number of housing units where the fuel for 

central air-conditioning was some fuel other than electricity; these housing units were treated as if the air-condtioning fuel was electricity.

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

sampled.

 N = No cases in reporting sample.

 Notes: ● Because of rounding, data may not sum to totals. ● See Glossary for definition of terms used in these tables.

 Source: Energy Information Administration, Office of Energy Markets and End Use, Forms EIA-457 A, B, C of the 2005 

Residential Energy Consumption Survey.

Energy Information Administration

2005 Residential Energy Consumption Survey: Preliminary Housing Characteristic Tables