While temperatures above ground change a lot from day to day and season to season, temperatures in the earth's surface below the "frost line" (usually about one meter deep) hold nearly constant between 8-13 °C all year round.

For most areas, this means that soil temperatures are usually warmer than the air in winter and cooler than the air in summer. Geothermal Systems use the earth's constant temperatures to heat and cool buildings.

They transfer heat from the ground into buildings using heat pumps in winter and reverse the process in the summer.

The transfer of heat is accomplished with the help of the flow of relatively cold fluid (water antifreeze) into the ground and the return of this fluid, after its temperature has risen by a few degrees by means of heat transfer.

The heat pump removes the heat from the fluid in the earth connection, concentrates it, and then transfers it to the building. The water that "lost" its heat is returned to the ground (closed circuit) to begin the process again. According to environmental protection bodies, Geothermal Heat Systems are the most energyefficient, environmentally clean, and costeffective systems for temperature control.

Since the transport part of the Geothermal System is constructed of polyethylene pipes, Plasson's proven ElectroFusion technology provides not only the long term seal, but also offers fully computerized control and monitoring during the system construction.