If you intend to disconnect from the electricity grid or simply want to reduce the CO2 emissions produced by your home by increasing home comfort, you can consider install a geothermal heat pump. A geothermal system with heat pump well sized, it allows you to heat and cool the entire house for free.
The purchase costs of the plant, as well as the investment for install the geothermal heat pump they are not comparable to those of a classic methane-powered system, but the cost is amortized over the years as such a system can eliminate all costs related to domestic space heating, the production of domestic hot water and summer cooling.
The ideal is to design the geothermal system in conjunction with the construction works of the same house, however it is also possible to install a geothermal heat pump on a pre-existing building, but in this case the design phase must be even more accurate. .
Ageothermal heat pumptakes advantage of thelandas a source of energy. For the installation it will be necessary to organize a series of horizontal pipes buried at a minimum depth ranging from 1 to 1.5 meters; it is necessary to respect this minimum depth to ensure that the system is not affected by the temperature fluctuations of the outside air: the earth has the advantage of undergoing fewer changes in temperature than the air and enjoying the thermal energy transmitted by the sun.
Who points to onegeothermal heat pumpmust have an area of land 2 to 3 times greater than the extension of the rooms to be heated. When it comes toheat pumps, the geothermal one, is the most expensive both for the need for space and for the complexity of the system.
Then it must be said that there are two types ofgeothermal heat pumps, one that indirectly exploits the sun, using the heat of solar radiation accumulated in the ground, and one that exploits thegeothermal energy properly said. In the latter case, it is not necessary to have a large surface area but, unless you live in particular areas of Italy, you will need to dig deeper. Not everyone can take advantage of geothermal energy proper (independent of the sun) but in some places in Italy this is possible even without reaching extreme depths; just think of the example of the Neapolitan, in particular those who live in the area ofsolfataraand inCampi Flegrei.
When you want to install ageothermal heat pumpable to exploit the surface thermal energy, the pipe laying depth varies from 80 cm up to 4 meters. What we have called "pipes" in reality, are real heat exchangers which, according to the quantity of rooms to be heated, must occupy a more or less extensive surface.
The heat exchangers can be structured in different ways: serpentine or spiral, they can be spiral, ring or basket. The choice of the type of development of the heat exchangers is made by evaluating various factors: shaded areas, the type of soil ... It is important to remember that, even if the exchangers are placed underground, it will not be possible to use that surface to install buildings. Any cover making shade would render thegeothermal heat pump. The surface can be used for the cultivation of a turf but without hedges or trees that can provide shade.
In the design of ageothermal heat pumpit will be necessary to identify the presence of cables and non-hydraulic pipes: electrical network, telephone cables ... any system must be located at a safety distance of at least 1.5 meters from the heat exchangers and at least 2 m away from hydraulic networks (water sanitary, waste water ...) so as to allow any maintenance intervention.
The yield of ageothermal heat pumpvaries based on many factors. In good conditions, if the heat exchangers are installed in a clayey soil rich in stagnation, the efficiency can reach 40 W / m2 with coil or spiral exchangers.
You might be interested in reading Geothermal energy: how it works
Photo from: caleffi.com