Pool heaters are used to heat water in swimming pools, spas, and hot tubs. Pool heaters include both electric and gas-fired products.
DOE finalized the current efficiency standards for pool heaters in 2010, and they took effect in 2013. The current standards apply to gas-fired pool heaters only and require a minimum thermal efficiency of 82%.
Pool heaters use energy both directly through the energy used to heat the water as well as indirectly by adding friction to the pool pumping system. The additional friction added causes the pool pump to use additional energy even when the pool heater is off. Additional energy savings could be achieved by encouraging hydraulically-efficient pool heater designs. Most electric pool heaters are heat pumps, which use a refrigeration system to transfer heat from the air to the pool water. However, some electric pool heaters still use electric resistance heating elements. Electric resistance pool heaters use more than three times as much energy as heat pump pool heaters.