An exhaust air heat pump system enables client to significantly reduce the energy costs of building and makes carbon footprint smaller.
The system is based on recovering the ‘waste heat’ in the exhaust air. This is carried out by a heat recovery unit placed in the attic or on the roof. The temperature of the waste heat is increased in a heat pump so that the recovered heat can be used for heating air and water in the building. The technology involved has been used for years and has proven very reliable. The system can use existing ducts and fans in the building.

Integration in heat recovery system

Exhaust air fans can be integrated in a heat recovery unit but that is not required for the system to operate. If the fans are integrated in the heat recovery unit, the old fans, which often consume a lot of energy, can be discarded. The heat pumps and water heaters are placed in a heat distribution room or some other available space, such as an old cold-storage cellar. The greatest advantages can be achieved in buildings in which the ventilation system uses forced exhaust, which is the case in most of the blocks of flats built in the 1970s to 1990s. The system has a payback period of 5–7 years. The return on investment is about 16%. The useful life, or the life cycle of the system, is approximately 20 years.