Heat Pump
A heat pump is the opposite of a heat engine. Rather than obtaining useful work as heat flows "downhill" from hot to cold, a heat pump uses work as an input in order to pump heat "uphill" from cold to hot.
A heat pump is the opposite of a heat engine. Rather than obtaining useful work as heat flows "downhill" from hot to cold, a heat pump uses work as an input in order to pump heat "uphill" from cold to hot.