Between 1993 and 2009, the South added the most housing units, up 8.6 million units. Air conditioning has been widespread throughout most of the South for many years, but many households in the South have shifted from room air conditioning to central air conditioning, notes the report. In 1993, when 89 percent of households in the South used air conditioning, only 65 percent of households used central air conditioning while 27 percent used room air conditioning (window or wall units). By 2009, 96 percent of households in the South used air conditioning and 82 percent of households used central air conditioning, while only 15 percent of households used room air conditioning (1 percent of households used both central and room air conditioning in 2009, down from 3 percent in 1993).
Central air conditioners often consume more energy because they cool more of the area within a home. In 2009, homes in the South with central a/c systems used an average of 3,382 kilowatt-hours per year (kWh/year) for air conditioning, while homes in the South that used room units only used an average of 1,882 kWh/year for air conditioning.
Home size in the United States has increased over the past 20 years, and home size in the South has grown faster than the country as a whole, the report says. The average home in the United States is now 5 percent larger than it was in 1993, while the average home in the South is 9 percent larger. The average home built in the South between 2000 and 2009 is 11 percent larger than one built in the 1990s, and 42 percent larger than one built in the 1980s. The increase in cooled area has increased at roughly the same rate (14 percent and 50 percent, respectively) since almost all new homes in the South have central air conditioning. Homes in the South are also more likely to have central air conditioning than homes in any other region.
There are differences in the income characteristics of households that use air conditioning, both in the number of households without any air conditioning and the households that use only room air conditioning. In the South, 8 percent of households with incomes in the lowest income categories do not use air conditioning and 25 percent use only room air conditioning. By contrast, only 1 percent of households with incomes in the highest income categories do not use air conditioning and only 3 percent use only room air conditioning. So although most households in the South use central air conditioning, the households not using it are largely those in the lowest income categories.
Publication date: 8/19/2013