What type of heating system may operate in conjunction with a heat pump for additional backup?

A gas furnace is commonly used as a backup heating system in conjunction with a heat pump. This combination is often referred to as a "dual-fuel" system. The primary reason for this setup is efficiency; the heat pump is effective in mild temperatures but can struggle to maintain comfortable indoor conditions in extremely cold weather. When outdoor temperatures drop below a certain threshold, the gas furnace can activate to ensure adequate heating.

Using a gas furnace alongside a heat pump allows homeowners to benefit from the cost-effectiveness of the heat pump in moderate conditions while relying on the gas furnace for dependable heating during colder periods. This strategic pairing optimizes energy use and reduces heating costs when temperatures fluctuate.

Other systems like electric furnaces, wood stoves, and solar panels, while useful in specific circumstances, are not typically deployed directly in conjunction with heat pumps as a backup. Electric furnaces can sometimes be used, but they tend to be less economical when you have a more efficient gas furnace available. Wood stoves and solar panels serve different purposes and are not standardized in pairing with heat pumps for this backup functionality.