A variety of heating technologies are available today. In addition to heat pumps, which are discussed separately, many homes and buildings use the following approaches:
Furnaces heat air and distribute the heated air through a building using ducts. Boilers heat water, providing either hot water or steam for heating.
Provides a way to heat a building using biomass or waste sources.
Can be supplied by centralized electric furnaces or by heaters in each room.
Uses the sun to heat either air or liquid and can serve as a supplemental heat source.
Can draw on a number of energy sources, including electricity, boilers, solar energy, and wood and pellet-fuel heating.
Used when the main heating system is inadequate or when central heating is too costly.