Like your refrigerator, heat pumps use electricity to transfer heat from a cool space to a warm space, making the cool space cooler and the warm space warmer. Because they transfer heat rather than generate heat, heat pumps can efficiently provide comfortable temperatures for your home. Some heat pumps can also provide a building with hot water. 

During the heating season, 

Heat pumps move heat from the cool outdoors into your warm house.  

During the cooling season, 

Heat pumps move heat from your house into the outdoors.