The refrigeration circuit consists of four essential elements:
through which the refrigerant undergoes changes of state which make possible the transfer of thermal energy.
Evaporator the refrigerant fluid extracts heat (to fluid of the external environment in heat pump mode, to the fluid environment to be conditioned in chiller mode); passing from the evaporator to compressor the refrigerant receives an additional intake of energy in the form of pressure and temperature.
To exploit the external air source can be advantageous to design the heating system so that the heat pump withdraw the air flow it needs, not directly from the outside but from a thermal environment within the most favored.
For this purpose they lend tunnels surrounding the basements of houses or ventilated crawl spaces: in the shelter of these structures and the heat input of the house and grounds, maintain a higher temperature in winter and lower in summer than outside.
The fulfillment of a heat requirement is achieved not with a drilling very deep but with more perforations with a maximum depth of 150 m.
The design of a probe system requires you to consider a number of factors that affect the efficiency of the geothermal system.
Depending on the space available, it is necessary to study the geometry of the system of probes so as to give them a distance mutual sufficient to prevent the thermal interference between a probe and the other: the range is variable between 4 8 m and also according to the conductivity of the soil.
The solution with geothermal horizontal probes requires less initial investment than the solution with vertical development due to the lack of charges against perforazione.Di is a less efficient because the more superficial layers of the soil most affected by changes in the weather outside.
Are required surfaces of land very ampie up to two times the surface area to be air conditioned.
The most common type of geothermal plants exploits probes of the vertical type which penetrate into the ground through geothermal wells of limited depth, the order of 100 m.
For a single plant are required more wells the number of which depends on the thermal requirement to be met and the thermal output of the subsoil from which the thermal energy must be extracted. The construction of the wells is preceded by a series of investigations aimed at the determination of: