What is Drain Water Heat Recovery?

Water is the most expensive natural element to heat and carries a significant amount of energy. Any hot water that goes down the drain carries away energy with it. That's typically 80–90% of the energy used to heat water in a home. Drain-water (or greywater) heat recovery systems capture this energy to preheat cold water entering the water heater or going to other water fixtures.

How does Drain Water Heat Recovery Work?

Drain water heat recovery technology works well with all types of water heaters. Drain-water heat exchangers can recover heat from the hot water used in showers, bathtubs, sinks, dishwashers, and clothes washers.

Water enters the home between 5-12ºC and is heated to 50ºC in the hot water tank. Showerhead temperature is approximately 41ºC and this water is flushed down the drain at 37ºC.

This energy can be brought back into your home to substantially reduce hot water heating costs. The drain waste heat exchanger will heat water coming into your home by 12ºC using the energy from water being flushed down the drain.