What is a heat pump?

Heat Pump compressors can be used in reverse direction so they can provide heating in winter. Sometime the units are provided with electric heating coil thus also known as heat pump.

Heat pumps are like conventional air conditioners except they also can provide heat in the winter. 

1. A heat pump is a device that provides heatenergy from a source of heat to a destination called a "heat sink". Heat pumps are designed to move thermal energy opposite to the direction of spontaneous heat flow by absorbing heat from a cold space and releasing it to a warmer one.