Introduction of Geo-Thermal Cooling System (GeTCo System)
Smart Life Ecology Co., Ltd.
The distribution of temperature 50cm under the ground is shown in the figure below (United States Department of Agriculture). Soil temperature of the Earth's surface is approximately proportional to the amount of radiant energy from the sun which is reached to the earth and is therefore high around the equator and less near the north and south poles.
The actual surface temperature is affected by the distance to the ocean, rainfalls or ocean currents, however the figure suggests that the underground temperature is determined largely by the relative angle of sun incidence (latitude).
Underground temperature of the desert (orange) is lower than that of the tropical rain forest (red) and is around 22 ℃.
The temperature 3 - 5 m under the ground in the desert regions becomes 22 ℃ or less, which is closer to the approximate average value of 15 ℃ of surface/underground temperature of the whole earth, and is stable throughout the year at about 20 ℃. On the other hand, the Earth's surface temperature in the desert region is in anhydrous state and become very hot, rising 40 - 50 ℃ in the sunshine hours.
Geo-Thermal cooling system (GeTCo System), proposed by Smart Life Ecology Co., Ltd., intends to promote energy saving by optimizing the energy diffusion path as Exergy.
In particular, very long tubes are filled with water which has the heat capacity 10 times higher than that of the sands, and placed to the ground surface and the underground. With the aid of circulation pump, the water is circulated through the tubes between the surface and the underground continuously day and night, so that the surface and underground temperatures get close to each other at an average of 24 hours.
Existing evaporative cooling system and ventilation fans are only used for peak cutting and it is possible in this way to greatly reduce the amount of the cooling water.
As the demand of fresh vegetables in the desert region is high, in many of the agricultural greenhouses, evaporative cooling system (Pat & fan system) have been introduced. Since five time more cooling water is consumed than the plant irrigating water, depletion of precious underground water has become a major issue in the desert regions.
Geo-thermal cooling system (GeTCo System) is shown in the figure above. By utilizing well water for heat exchange process, the consumption of total cooling water can be reduced. The temperature near the plants can be lowered by placing a sufficiently long tube around them. Furthermore, it is attractive for users to build their own system by himself by combining material which can be easily obtained in the local market with reasonable prices.