Do you know that you can heat or cool your house by ground heat? Geothermal air conditioning principal is very simple. Ground surface temperature is stable at 16 - 18° C. As a result we can profit from the temperature difference (between ground and surface), we can heat and cool rooms both during winter and summer. The geothermal - solar house provides heating - cooling without fossil sources. A very environmental friendly solution. Passive Solar Heating is the most cost effective means of providing heat to buildings. In general terms, the amount of solar energy that falls on the roof of a house is more than the total energy consumed within the house. Passive and active solar applications, when included in initial building design, add little to the cost of a building, yet have the effect of realizing a reduction in operational costs and reduced equipment demand.

Hybrid heating and cooling system using geothermal and solar energy

Solar collectors hot water is transferred in an insulated storage tank, heating the central heat water and the hot use water. If the amount of hot water isn't enough then geothermal heat pump starts working , contributing to the needed energy. Great reduction in fossil fuels expenses and environmental friendly. Storage tank being the heart of this solar - geothermal system is properly and carefully designed and insulated for this purpose.

Storage tank function is totally automatic, helping user to enjoy perfect living conditions.

Storage tank contains water heated by solar collectors.
This water is not under pressure and it remains the same playing the role of heat transfer to two exchangers: one plastic, connected with water supply network and a metal one connected with the heat network.
As a result, when hot water use is needed, cold water from water supply passes through the storage tank plastic exchanger and going out has the static water temperature.
In the same way , central heat hot water before entering the pump will pass through the storage tank metallic exchanger gaining static water temperature.
As a result , when solar energy is enough for static hot water up to 70° C, then the geothermal will not operate at all, since the returning hot water temperature , will , already , be higher than needed ( since underfloor heating uses 45° C hot water)
As a matter of fact, central heat uses a percentage from the static water deposited energy , though the rest is used for hot water use.
This is a totally free of charge solar energy system used for both central heating and hot water use.

When sun is not enough, during night or cloudy days, then the geothermal heat pump operates and heats central heating water. If in the same time ,hot water use is needed, then a three way valve opens and hot water circulates from the heat pump to the metallic exchanger. In this case hot water is heated by the pump.
Since Greece has more than enough sunny days , even during winter time, especially in Southern areas, it's obvious that this combination can achieve big energy and money savings, especially combining with low temperature heating systems (e.g. underfloor heating system).