An HVAC unit is a piece of equipment that is used in residential, commercial or industrial settings to manage its heating or cooling system. Certain HVAC models can also be used to provide a constant flow of fresh air into a building to minimize bacteria and odors.
As of 2015, there are various types of HVAC units available on the market, such as cooling-only, heat pumps, window air conditioners and chilled water systems. A cooling-only system is generally used to decrease the temperature inside a building during times of the year where the outside is hot. A heat pump operates in a similar manner, but with the flow and temperature of air reversed.