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Heat from grey water:

The concept: Warm waste water -
a previously unexploited heat source!

Grey water is the waste water discharged from bath tubs, showers, sinks and the washing machine (not from the kitchen because of fats). It is produced in almost constant quantities, irrespective of the seasons or weather conditions. With the ThermoCYCLE® we make use of this repeated occurrence of heat before it is lost for ever in the sewer network.

With the highly efficient process principle of the patented ThermoCYCLE®, the valuable energy is extracted from the discharged grey water within the temperature range of 28°C - 40°C. This free heat is used indirectly for pre-warming the service water or for assisting the heating system. Approximately 15 kWh can be recovered from around 1,000 litres of grey water.

Drained shower water as a heat source

shower in a public bath

Hot water circuit: When we use the shower, the heat of the grey water can be used with a slight delay for heating the service water.

washing machine

Depending on the washing programme, the temperature of the grey water discharged from washing machines is relatively high, especially in laundries.


Energy Globe 2013

Patented and award-winning
The ThermoCYCLE (TC-BM) is a waste heat recovery system in which hot, discharged grey water is collected and filtered. The heat is recovered by means of a heat exchanger and transferred to a Hygienic Storage System (HS-TC) for pre-warming the service water and for heating system assistance.
Savings of up to 25 percent are realistic for recharging the Hygienic Storage System.


  • Service water
  • Room heating
  • Service water and room heating
  • Use of the recovered heat is also possible as an energy source for a heat pump!



  • Grey water (e.g. shower, washing machine ...)


Collection storage tank
+ Fine filter
+ Heat exchanger
+ Cleaning module
= TC-WHR module



ThermoCYCLE System
The exact layering of the HS-TC Hygienic Storage System permits maximum utilisation of the thermal energy recovered with the TC-BM ThermoCYCLE. The system can be used anywhere where hot water is drained, for example at camping sites, recreational facilities, hotels, swimming pools or apartment buildings with approximately five or more apartments.

Service water and/or room heating
TC-BM ThermoCYCLE + HS-TC Hygienic Storage System


Heating accumulator
+ Service water exchanger
+ Stratification system
+ Solar exchanger
+ NEXT hard foam insulation
= Heat management centre


Further information is available in pdf format in the download area or in German.



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