ComfoFond - geothermal heat exchangers
The Zehnder Comfosystems are fresh air systems that recycle approx. 90% of the heat in the exhaust air and use it to heat the fresh air. This saves considerable heating costs. An upstream earth heat exchanger pre-conditions the outside air. This increases the effective heat recycling efficiency by another 4 to 5 %.
The earth heat exchanger systems Zehnder ComfoFond use the slow-changing temperature of the earth in approx. 1.50 to 2.00 m depth. In winter, the earth has an approximate temperature of 8°C, and warms the air before it reaches the ventilation system. In summer, the earth temperature is approx. 12°C and the principle works in reverse. The warm outside air is cooled in the earth and directly piped into the house. This cooling effect makes it possible to keep the windows closed and to keep the warm air outside.
The earth heat exchanger packet ComfoFond includes matched components for simple installation:
- Appealing air intake tower made of stainless steel
- Cleanable pipes with smooth inside, made of plastic (HDPE) with large heat-exchanging surface due to an outside profile
- Wall bushing that is simple to install
- Collection box with condensate drain
- Whole system radon-tight
The brine earth heat exchanger Zehnder ComfoFond-L was specifically designed for building on a small piece of land, buildings with cellars exposed to pressurised water or buildings without cellars. The ComfoFond-L takes up the environmental energy (heat or coolth) through a PE pipe filled with brine, which is pumped to a water-air heat exchanger. The controls required for this purpose are integrated in several devices. The heat exchanger transfers the heat or coolth to the incoming external air before it enters the ventilation system. The PE pipe is installed in 1.5 m depth, e.g. in the building pit or in the area of the house connections.