Heat pumps work by transferring heat from one area to another. When in cooling mode, a heat pump works exactly like an air conditioner. When in heating mode, a heat pump absorbs heat from the outside air and transfers it to the air inside of the home.
Heat pumps can be more efficient than a traditional forced air furnace since they do not produce heat by using natural gas or other fuel sources; they simply transfer heat, even in colder months.
In colder climates, much like in most of Canada, the frigid winter temperatures of the coldest months will not allow a heat pump to function as effectively to heat your home. For this reason, it is recommended to use a heat pump primarily as a cooling system in the summer months and as a secondary source of heat in the winter, combining it with a forced air furnace to tackle the coldest winter months without sacrificing your family's comfort. This method allows your home's heating & cooling system to take the most advantage of the heat pump's energy efficiency and heat the home when the temperature is milder, but switch over to the furnace during the coldest parts of the year.