Energy saving in greenhouse production is considered as essential to reduce the cost of the out of season agricultural products. Geothermal fields of low enthalpy exist in many rural areas in Greece and the heating systems of low operational cost, such as the geothermal, are easily adopted by the farmers. Also, materials introduced by this research seek the interest of the relevant manufactures.
System of pipes located on the ground surface, between the plant rows or directly in the plant rows at the greenhouse. It can be arranged in unit loops but also with a parallel system of two or three pipes in a loop.
The installations are proven as very good and convennent for the Mediterranean (as unit) and other climate regions (in combination with other types of heating installations). Simple maintenance and feasibility for easy arrangement of heat exchangers between the plant rows or in the plant canopy. Sim-ple change of heat exchangers and their rearrangement, even during the heating season. In general, it is not convenient for temperatures below 35 Deg.C because resulting with very dense arrangement of numerous pipes in the greenhouse interior. They are not convenient for cold climates as unit installation inside because not of¬fering the protection against the cold radiation of the environment