While Goodman AC systems and freezer coolers stand out as examples of heat pumps, the term “heat pump” is more general and relates to many HVAC (heating, ventilating, and air conditioning) devices used for space heating or cooling down. When a heat pump is used for heating, it employs the same basic refrigeration-type cycle used by an air conditioner or a refrigerator, but in the opposite direction – releasing heat into the conditioned space instead the surrounding environment. In this use, heat pumps generally draw heat from the cooler external air or from the ground. In heating mode, heat pumps are three to four times more efficient in their use of electric power than simple electrical resistance heaters. Typically installed cost for a Goodman heat pump is around 20 times higher than for resistance heaters.