What Does an HVAC System Do?

At the most basic level, an HVAC system takes in air, cools or heats that air, and blows it into an indoor space, according to the American Society of Heating, Refrigerating and Air-Conditioning Engineers. That space could be a specific room or an entire building or structure, such as a house, office, school, airport, or even a submarine. An individual component of an HVAC system may serve dual purposes. For example, your home could have a separate air conditioner and furnace, or a heat pump for both cooling and heating.