Space, water heaters are the top energy consumers in households

The Energy Information Administration’s latest Residential Energy Consumption Survey found that space heating and water heating were the top two energy-consuming uses in U.S. homes in 2015.

The survey found that residents of single-family detached homes consumed nearly three times more energy on average than residents living in an apartment building with five or more units. In single-family homes, space heating was by far the largest end-use at 46 percent of total consumption. In large apartment buildings, space heating accounted for only 25 percent of consumption.

The number of people living in a house is a key determinant of energy consumption in homes, particularly for water heating. The survey revealed that a two-person household consumed 12.5 million British thermal units (Btu) on average, or 16 percent of overall consumption, to heat water. However, a four-person household consumed nearly twice as much energy for water heating at 22.7 million Btu per home, or 24 percent of overall consumption. The number of occupants in a home had less of an impact on energy consumed for space heating and air conditioning.

Further, the study found that households paid $37.55/million Btu for electricity compared with $10.31/million Btu for natural gas in 2015. Electricity is the dominant fuel for air conditioning, refrigerators, and lighting.

Because space heaters use a mix of electricity, gas and other fuels, expenditures for space heating and water heating tend to be lower. While space heating and water heating accounted for 62 percent of household energy consumption in 2015, they were only responsible for 44 percent of household energy costs because of the mix of fuels used to power them.