The Combi Systems (solar thermal systems for domestic hot water generation and space heating) are included in the wider category of the forced circulation solar systems. These systems combined with thermal energy distribution systems of low temperature, because the medium (water or air) is heated in temperatures of 50-60°C.
It is thus best combined with floor heating systems, fan coil units and central cooling systems.
It is worth mentioning that a cooling device consists of a copper heating element with aluminium fins a fan and different regulation components. The water flows through the heating element and the fan recirculates the space air and forces the air to circulate within the heating element.

According to the external conditions, the automation system of the system ensures the correct utilization of the solar power. Thus, if the solar radiation is adequate, the thermal needs are covered straight by the collectors. In case there is adequate solar radiation but there are no thermal needs, the energy is accumulated in the water storage tank. If there is only accumulated energy available, the thermal needs are covered straight by the storage tank.
Lastly, if there is no energy stored, the thermal needs are covered by the auxiliary energy source.

The said systems consist of the solar collectors, the hot water storage tank, the water storage tank for space heating, the heat exchangers, the auxiliary energy source, as well as the heat pumps and automations needed for the smooth operation of the system.

The installation of the above described systems significantly decreases the cost of the buildings, because, if configured correctly, they can provide the building with space heating during the winter months and cooling during the summer ones, covering at the same time the needs in domestic hot water.