Wastewater calories can now be used to heat water in the home or even to heat the home itself. Some elements of explanation on this new technology.
Every day, with a shower and the current needs of the house (dishwasher, sink, washing machine, etc.), more than a hundred liters of hot water per person go down the drain. This wastewater is called "gray water". They represent an important calorific deposit, which it is possible today to exploit.
How does it work?
There are several technologies for recovering the heat from this gray water. With the Degrés Bleus offer from Suez Environnement, a heat pump and an exchanger recovers the calories contained in the sewers. This is how the Levallois-Perret swimming pool is heated, for example, and soon an entire Nanterre eco-district. Biofluides Environnement's ERS offer works on the same principle. There is also a simpler and less expensive system, the ThermoCycle, which stores wastewater in an accumulator through which a preheating coil. Or, the EcoRC36 from EHTech recovers the calories from the shower in real time and sends them back to the mixer or the tank to continue heating the water. Finally, the Power-Pipe simply consists of a drain pipe surrounded by a flat copper coil. It is connected to the hot water tank, the shower mixer or both.
How much does it cost ?
The Suez Environnement and Biofluides Environnement installations cost around € 2,000 excluding tax per accommodation for a building. ThermoCycle costs around 650 € per accommodation for a building of around 30 apartments, as well as the Power-Pipe. For EHTech, it will take around 800 €.