Dual-Fuel System
An HVAC configuration pairing an electric heat pump with a gas furnace, automatically switching to gas when outdoor temperatures drop below the heat pump economic crossover point.
Why It Matters
Dual-fuel provides the efficiency of a heat pump most of the year while using gas backup for the coldest days when heat pump efficiency drops. A transitional step toward full electrification.
Related Tools
Related Terms
Heat Pump
An efficient HVAC system that transfers heat rather than generating it, providing both heating and cooling. Air-source heat pumps are most common; ground-source (geothermal) are most efficient.
Cold-Climate Heat Pump (ccASHP)
A heat pump specifically designed to maintain high heating capacity at very low outdoor temperatures (typically rated to -13°F/-25°C or lower).
COP (Coefficient of Performance)
The ratio of heating or cooling output to electrical energy input for a heat pump. A COP of 3.0 means the system produces 3 kWh of heat for every 1 kWh of electricity consumed.