Extensive earthworks, which are necessary when setting up earth-coupled systems, or expensive drillings of bore holes are not required. When set up outside, channels for air intake and air outlet are not necessary, only the ductwork for heating purposes and an electrical connection are required. The ground on which the unit will be placed must be firm enough.
Modern air/water heat pumps can operate and extract heat in external temperatures down to minus 20°C. But the efficiency of regular air/water heat pumps is reduced as the temperature of outside air drops. That’s why, on extremely cold days, the water which has been pre-heated by the heat pump must be further heated by an electrical heating element or a boiler.
More effective are heat pumps with special vapour injection systems (EVI cycle) – the next step in the development of the heat pump – the efficiency of which is only slightly reduced as external air temperature drops. These systems make use of vapour injection (comparable with turbo chargers used in cars), which is activated only when the temperature difference between the external air and the heating system is substantial. This allows for effortless integration of such heat pumps with existing radiators of the existing heating system. They can easily function as the only heat source for room and water heating, throughout the year.
Air/water heat pumps which are designed for outside use are made of weather resistant, anti-corrosion materials, which make it possible to use these pumps throughout the year. The housing and the vaporizer of state-of-the-art units have a special coating which makes the pump suitable for continuous use in heavily saline environments as well (close to seashores, for example).
Special construction and acoustic insulation of the external coating make sure that the fan and the compressor are inaudible. The unit has extremely low sound emissions. Still, certain conditions must be considered when selecting a location for the unit:
Convectors are used for cooling and additional or independently heating. In contrast to air-conditioning systems, where the medium is refrigerant, the convector use water. Regulation of convector is usually not connected with a heat pump. Heat pump only makes hot or cold water available, which is then, according to the needs, used or not.