Which heating mechanism is used by a heat pump water heater?

• A. Gas Burner
• B. Electric resistance coils
• C. Refrigeration system
• D. Solar energy collection

Answer: (C)

Heat pump water heaters move heat rather than generate it directly. They use a refrigeration system—like a fridge or air conditioner: a refrigerant absorbs heat from the surrounding air in an evaporator, is compressed to a higher temperature, and then releases that heat into the water as it passes through a condenser. The cycle repeats, transferring warmth from the air into the tank with electric power mainly used to run the compressor and fans. This method makes heat pump water heaters much more efficient than electric resistance heating because they multiply the input energy by moving existing heat rather than creating it from electricity.

Gas burners heat water by burning fuel directly. Electric resistance coils convert electricity straight into heat. Solar energy collection uses sunlight to heat water, typically via solar collectors. These approaches are different mechanisms than the refrigeration-cycle method used by a heat pump water heater.