Sustainable building - Geothermal
Use of Geothermal energy in single-family houses
Geothermal can be used in single-family homes to provide heating and cooling. Although the use of geothermal energy in single-family homes is less common than in multi-story buildings or massive housing projects, more and more luxury homeowners are opting for this option due to its energy efficiency and low environmental impact.
They normally drill wells to a depth of 100 to 150 meters. The cold water is pumped from the surface to the bottom of the well, where it is heated or cooled when it comes into contact with the rock, (every 100 meters of depth reached, one degree is gained). The hot or cold water is pumped back to the surface, where it is used to heat or cool the house through a heat exchanger.
The larger the home and therefore its energy needs, the more wells and depth will have to be made. The maximum depth per well is 150 meters, although they are usually 100m. One well can be estimated for every 120 m2 built (with habitability uses), so for a single-family house of about 500 to 600 m2, 4 or 5 wells will be made, depending on the dimensioning of the installation and the energy requirements.
In general, the vertical type installation is better than the horizontal one, since the horizontal installation has worse performance and leaves the terrain conditioned. Only if there is no other remedy is the horizontal work field usually used. In 95% of the land, vertical drilling can be carried out without problems.
The main advantage of using geothermal energy in luxury single-family homes is energy efficiency, since the natural heat or cold of the subsoil is used to heat or cool the house. In addition, it does not require fossil fuels, which reduces CO2 emissions and contributes to the fight against climate change. However, the cost of installation can be high and requires a significant investment to implement.
In general, it can be said that for this type of facility, for every 1 KW of electricity that we consume from the electrical network, the machine generates 4-5 KW of heat.
Operation of a heat pump:
A geothermal heat pump works through a process in which heat is extracted from the ground and used to heat a building. The process begins with the use of a heat transfer liquid, such as glycol, which is pumped through pipes buried in the ground. As the liquid passes through the pipes, it cools on contact with the cooler ground and, at the same time, warms on contact with the warmer ground. This temperature change in the liquid is geothermal energy that is drawn from the ground.
Then, the hot liquid returns to the evaporator of the heat pump, where it gives up its heat to the refrigerant that circulates through the refrigeration circuit, causing it to heat up and evaporate. The hot refrigerant is then compressed by the compressor and becomes a hot gas that passes to the condenser, where its heat is transferred to the heating or hot water generation system. The refrigerant is cooled through an expansion valve and the cycle begins again.