[1] Retaining heat from groundwater

‘The whole concept came into being gradually,’ recalls Kurt. ‘When we started building the house in 2000, the street was still without a natural gas network. I did not like the idea of heating our home by fuel oil, the most common alternative for natural gas. So I started looking around for residential heat pump systems. I finally bought a system from Nordic, a Canadian brand. The installer was a geologist, which was perfect since I could handle the electrical part of the installation myself.’

‘The system uses a closed circuit that consists of four 35 meter deep wells. In actuality, it does not retain heat from the ground but from a groundwater pool that has a more or less constant temperature. This is different from most heat pump systems in Europe. They usually have a long snake-like tube just below the surface of the ground. This results in a lower installation cost, but also in a lower efficiency since the temperature of the ground close to the surface is not constant.’