Drain heat recovery pipes are a simple technology that saves energy used to heat water. This pipe uses warm water flowing down the drain pipe to preheat the water entering the hot water tank. Preheating water reduces the energy required to heat the water to the set temperature. The technology is simple. The cold water entering your home flows through a series of coils tightly wound around the drain. The heat from the drain is transferred through the copper wall of the heat recovery device, heating the cold water before it enters the water heater. The heat is transferred, but the discharged water will never mix with fresh water.
Drain water heat recovery