Energy Intensity for Cooling is Greater in Warmest Climates in U.S.
According to a recent report from the U.S. Energy Information Administration (EIA), titled “Commercial Buildings Energy Consumption Survey” (CBECS), the energy intensity for cooling commercial buildings in the U.S. depends on the climate the building is located in. (Energy intensity in buildings is defined as the energy consumed per square foot of floorspace.)
The EIA noted that U.S. commercial buildings in hot or very hot climates, which are primarily in the southern parts of the country, were more than six times more energy-intensive for cooling (14.2 thousand British thermal units per square foot [MBtu/sf]) than buildings in cold or very cold climates (2.3 MBtu/sf).
The climate zones in the EIA’s CBECS (which uses 2018 data) are based on the climate zones in ANSI/ASHREA Standard 169-2021, “Climatic Data for Building Design Standards,” This standard designates climate zones using annual average temperature and precipitation data from 1994 to 2019.
The EIA calculated cooling energy-intensity estimates for climate zones by dividing the consumption of major fuels (electricity, natural gas, district heat, and fuel oil) for cooling by the total floorspace of buildings that used one of those fuels for cooling in each climate zone.
The report noted that commercial buildings in warmer climate zones were both more likely to be cooled, and also to cool larger portions of their floorspace. In 2018, 52 percent of buildings in the hot or very hot climate zone reported cooling all of their floorspace. In contrast, only 25 percent of buildings in the cold or very cold climate zone reported cooling all of their floorspace.
Electricity is the predominant energy source used for air conditioning, accounting for 98 percent of the 589 trillion Btu of major fuels consumed for cooling in 2018. Only the mixed mild climate zone had a slightly lower share of electricity consumed for cooling (96 percent). An additional 55,000 buildings (one percent of buildings with cooling) used district chilled water systems for cooling. Other fuels used for cooling include natural gas, district heat, and fuel oil.
In 2018, 55 percent of commercial buildings with cooling reported using packaged air-conditioning units. Packaged cooling equipment, which is the most common cooling equipment across all climate zones, is defined as a self-contained unit that can provide either space heating or cooling, as desired. Packaged units were used by 66 percent of air-conditioned buildings in the hot or very hot climate zone and by 48 percent of air-conditioned buildings in the cold or very cold climate zone.
The EIA’s CBECS is the only nationally representative survey that collects information about U.S. building characteristics and energy use in commercial buildings. CBECS publishes a variety of data including building size, activity, energy sources, energy end uses, operating hours, and more.
The CBECS survey process spans more than four years, from developing the sample frame and survey questionnaire to releasing data to the public.