A geothermal energy cooling / heating system is based on using the full potential of the constant temperature and thermal conductivity of the earth’s substructure.
We can see this phenomenon in basement areas where during the summer the area is cool and during the winter warm without the use of air conditioning.
Geothermal energy can be broken down into two categories: Open loop systems and closed loop systems.
Open loop geothermal energy for cooling / heating is the pumping of underground water source through a Heat pump (or VRV) and the return of the water after the energy transfer. This method needs a constant water supply.
Closed loop Geothermal energy systems can be divide into two categories.
Horizontal closed loop Geothermal energy system is installed at least 1.5 meters below the ground with pipe spacing of at least 1.8 – 2.2 Rm per m². Output is 20 – 35W/m². This system has the disadvantage of requiring a large area to be installed.
Vertical closed loop Geothermal energy system where the loop is installed in a vertical bore well (6” – 8” diameter) and 60 – 120 deep. The minimum distance between the wells is 5 meters and the output is 40-70W/meter of depth, and depending on the soil structure. This system is more popular as you need less space and have a higher output.
The heat which is collected from the earth is transferred to the system(Heat pump, CHILLER, VRV e.t.c.) and the exchange is made via heat exchangers and transferred to the cooling circuit of the unit as in a normal system. Due to the fact that the temperature is constant in the earth (±18.5°C) the energy required for this this process is much less than in a normal system where the air temperature is 40°C in summer and 5-10°C in winter.
Geothermal energy can be used for under floor heating, fan coils, or for VRV systems, and the savings in comparison to a normal Air to water system can be up to 50-60% depending on the application and use of system.