A Hybrid system, also known as dual-fuel system, consists of an electrical heat pump and a backup heating system (a gas furnace or an electric resistance heater). A significant amount of the energy needed to heat a home throughout the year is used when the temperature outside is not too cold. The air-source heat pump used to provide most of the home’s heating needs by extracting heat from the air outside (using refrigeration cycle) in milder outdoor temperatures and releasing it inside to heat your home. Standard air-Source Heat Pumps (ASHP) work best when outdoor temperature is above 40°F (~4°C) and Cold Climate Heat Pumps (ccASHP) when the above -22°F (-30°C). When a heat pump can not provide heat efficiently, the hybrid system automatically turns off the heat pump and switches to the backup unit, (gas furnace or electric resistance heater) for more efficient heating.