Geothermal heat pumps heat and cool buildings
Although air temperatures above ground change throughout the day and with the seasons, the temperature of the earth 10 feet below ground is surprisingly steady, between 50 degrees Fahrenheit (°F) and 60°F. For much of the United States, the soil temperature is usually warmer than the air temperature in winter and cooler than in summer. Geothermal heat pumps use the earth's steady temperature to heat and cool buildings.
Geothermal heat pumps transfer heat into or out of buildings
In winter, geothermal heat pumps draw heat from the warmer ground (or nearby water) into buildings.
In summer, the process is reversed. The system pumps unwanted heat from inside buildings into the cooler ground.
A type of geothermal heat pump system
Source: U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (public domain)
Geothermal heat pumps are energy efficient and cost effective
According to the U.S. Environmental Protection Agency (EPA), geothermal heat pumps are the most energy-efficient, environmentally friendly, and cost-effective systems for heating and cooling buildings. Many types of buildings can use geothermal heat pumps, including homes, office buildings, schools, and hospitals.