Rainwater collector combined with heat exchanger

by: Mirjam Visser, 2011-06-07 04:00:17 UTC
Sustainability Aspects: Saves 50% of the tapwater an average household uses as well as 25-30% of the energy used to heat water for central heating


A rainwater collector based under the ground floor of the house combined with a heatexchanger that makes use of the water in the collector instead of drilling a well of several hundred meters deep. It saves both on drinking water and on energy at the same time!

The HR KlimaRain system exists of a water bag with big capacity which is placed in the crawling space underneath the building or house. Rainwater is collected via a self cleaning filter, the heat exchanger takes the energy out of the temperature of the rainwater. By making use of the rainwater instead of drilling a well about 7500 euro’s can be saved on installation cost.

Energy from water.
The heat of the earth underneath the crawling space, the temperature of rainwater and the heating losses of the building heat up the water in the water bag. In case of lack of rain the bag is automatically filled with a small amount of tap water to guarantee the functioning of the heat exchanger. As long as the temperature is above 3,5 degrees Celsius the heat exchanger can recover heat from the water.

For new as well as existing buildings
The advantage of new buildings is that they are much better isolated and there might be an option to integrate the system with other energy sources like solar collectors. The system is most effective for installations with a thermal power of 5-8kW, for bigger systems it makes sense to combine it with solar collectors

The advantages of the HR KlimaRain System:

  • Doesn’t need a well so saves on installation cost
  • Saves 25-30% on the heating bill compared wih gas fuelled central heating installation
  • No calcium in rainwater so less cleaning agents needed to clean toilet, bath and washing machine
  • Saves 30% on cleaning agents and laundry detergents
  • Cooling options
  • CO2 emission reduction
  • Buffers with heavy rain and prevents overflows
Designer: efrarain, klimaatconcept
Manufacturer: Klimarain Solutions
Category: save drinking water and energy
Websites: www.klimarain.nl/


Liters waterconsumption
Liters waterconsumption
per person per day per activity in the Netherlands by Efrarain

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