The electric heat pump can extract heat from the outside air even in extremely cold temperatures. It may be hard to believe, but air at 0 degrees contains almost 90 percent of the heat it contains at 70 degrees. But when the outside temperature is very low, there may not be sufficient heat in the supply air to keep your home warm. Supplemental heat may be needed about 5 percent of the time in our area. Heat is extracted from air by the outdoor coil.
Refrigerant gas carries heat to the indoor unit.
Circulating indoor air picks up heat and carries it throughout the house. When the outdoor temperature causes the heating capacity of the electric heat pump to equal the heating requirements of the home, this is known as the balance point. If the outdoor temperature is extremely low, falling below the balance point, supplemental heat is required. Although supplemental heat is rarely needed, less than 5 percent of the year, it's best to be prepared. To provide this additional power, heaters are installed in the indoor unit.