Where groundwater is available at an acceptable depth and in sufficient amounts, it offers the best possible seasonal performance factors. A constant temperature of 8 to 12 °C guarantees an optimum heating operation. This requires two wells to be constructed – one delivery and one return well. The return well should be at least 15 metres away from the delivery well in the flow direction of the groundwater. 1 kW heating output requires approximately 250 litres per hour groundwater. The capacity must be verified by a continuous pump test. The amount of suspended matter in the water must not exceed or undershoot certain thresholds, so a water analysis must be carried out. A permit from the local water board is required.

Active or passive cooling: the use of water as a heat sink is suitable for both active and passive cooling of building interiors. Design/engineering information