Free Cooling makes it possible to cool the home naturally in summer. The heat pump is not in operation, so the function is practically energy and cost neutral.
Geothermal probe heat pumps and groundwater heat pumps utilise the low temperatures of the ground or water to lower the room temperature. Cold water flows through the underfloor heating via a heat exchanger, extracting around 2 - 4 °C of heat from the interior rooms. This excess heat is temporarily stored in the ground and is used by geothermal probe heat pumps during the winter months for energy-efficient heating with improved efficiency.
The energy requirement for circulating the coolant is minimal. As the heat stored in the ground increases the efficiency of the heat pump during the heating period, the energy consumption remains almost neutral. The average cost of passive cooling in a detached house is around CHF 30 per year (based on an electricity price of 20 centimes/kWh). Compared to the high operating costs of air conditioning systems, this is an extremely cost-effective solution.
Advantages
Low investment costs
No draughts
Low operating costs
Conservative use of resources
Free cooling only works with geothermal probe heat pumps and groundwater heat pumps. With air/water heat pumps, some models have the option of active cooling. In this case, the cooling circuit of the heat pump is reversed and the pump is actively operated to achieve lower temperatures in the rooms.
This technical detail ensures that the ambient heat is channelled directly into the geothermal probe and stored there.