water heat recycling
Heat from shower drains is reclaimed and used to warm up the cold water supply for the shower. By preheating the cold water, less hot water is needed for an enjoyable shower.
how it works
The cold water that is put into a water heating device can be preheated using the reclaimed thermal energy from a shower so that the input water doesn’t need as much energy to be heated before being used in a shower, dishwasher, or sink. The water entering a storage tank is usually close to 11 °C but by recovering the energy in the hot water from a bath or dishwasher, the temperature of the water entering the holding tank can be elevated to 25 °C, saving energy required to increase the temperature of a given amount of water by 14 °C. This water is then heated up a little further to 37 °C before leaving the tank and going to the average shower. An in-house greywater recycling tank holds 150-175 litres allowing for the majority of waste water to be stored.
Sources : Wikipedia, Pinterest