A heat pump is an efficient form of electrically based heating and cooling.An air source heat pump is a heating and cooling system that transfers heat between the outdoor air and the indoor air. It can serve as an energy-efficient alternative to traditional heating and cooling systems like furnaces, boilers, and air conditioners.ASHP’s can also operate in reverse, acting as air conditioners during warm weather. In cooling mode, the heat pump extracts heat from the indoor air and releases it outdoors, cooling the indoor space.