Heating systems in buildings are also major sources of energy use and emissions. Switching to or adding a heat pump is a key action because heat pumps are efficient systems that use less energy than most other home heating systems. Because they are electric, they can be made emissions-free when renewables are added at the building or community level.

Heat pumps are home energy systems that use electricity to transfer heat from a cool space to a warm space, making the cool space cooler and the warm space warmer.

During the winter, heat pumps move heat from the air or ground outdoors into your house to warm it. During the summer season, heat pumps move heat from your house into the outdoor air or ground, providing air conditioning.^{^[1]}

Ductless air source heat pumps are easy to install and can provide primary heating and cooling, often with a backup source of heat available, such as the building’s previous heating system. They are very efficient and are a cost-effective option when an existing building does not have ducting.^{^[2]}Typical costs for these systems were $3600 in 2020, with a total cost including installation of approximately $6,100.^{^[3]}

Ducted air source heat pumps are typically used as a primary heating system and are installed in new buildings or replace a current furnace or heating system. These heat pumps can reduce electricity use for heating by up to 50% compared to baseboard and furnace heating systems. They also dehumidify and cool more efficiently than traditional air conditioners in the summers. Technology advancements mean these systems are now viable in all areas of the United States.^{^[4]}Fully installed, these systems can cost between $3,500 and $7,500 depending on the size of a building, the number of indoor air handler units required. The costs are higher if ducting does not already exist in the building.

Ground source heat pumps exchange heat with the ground and are often installed in new buildings as a primary heating and cooling system. They are very efficient, reducing energy use by 30%-60%, and are low-emitting but are typically more expensive to install. Typical costs for these systems were $4650 in 2020, with a total cost including installation of between $12,650 and $19,650.^{^[5]}

^{^[1]}^{^[2]}^{^[4]} Heat Pump Systems | Department of Energy
^{^[3]}^{^[5]} U.S. Energy Information Administration. June 2018. Updated Building Sector Appliance Equipment Cost and Efficiencies, 84 p.