United States. Based on information collected through the EIA's Residential Energy Consumption Survey (RECS) for 2015, only 12% of the nation's 118 million homes had a central air conditioning unit that is controlled using the programmed thermostat.
About one in three households that use central air conditioning does not have a programmable thermostat. But even for those homes that use central air conditioning and have a programmable thermostat, more than two-thirds of those homes control temperatures without actually programming the thermostat.
According to the RECS, respondents were asked how indoor temperatures are set during the summer. Nearly half (45%) of households using central air conditioning units said they set the thermostat to a temperature and left it there most of the time. The second most common approach was to manually adjust the temperature at night or when no one was home (26%). The third most common approach was the use of a programmable thermostat to automatically adjust internal temperatures (18%), and it was more common than manually turning equipment on or off (11%).
For households that use individual air conditioners for windows, walls or laptops, about half (45%) opted to turn equipment on or off as needed. Programmable thermostats are relatively less common in individual units, with only 5% of households with that equipment reported using a programmable thermostat.
RECS respondents who used central air conditioning or individual units were asked to provide the typical indoor temperature during the summer when someone was at home, when no one was home, and at night. Although centrally air-conditioned homes and individual units reported similar temperatures when no one was home (74°F - 23°C on average), those with individual units kept their homes at colder temperatures at night and when someone was home.
Source: https://www.eia.gov
