Our planet is constantly accumulating energy, so much so that 99% of it is at a temperature above a thousand degrees Celsius. The Earth works like a huge battery that is constantly recharging with the sun’s rays and the heat coming from the deepest layers.
This inexhaustible source can be used to heat and/or cool buildings and houses, which is why it is an attractive option to increase the efficiency and sustainability of buildings.
Geothermal air conditioning systems use the thermal inertia of the subsoil at a shallow depth. By means of a machine it is possible to extract the energy and then transfer it to the interior of the buildings, achieving an optimal temperature with an operation similar to that of air conditioning.
Geothermal energy extraction systems
Depending on the characteristics of the terrain, at a certain depth the temperature becomes constant. To access this heat, several holes between 10 and 15 centimeters in diameter must be made in which geothermal probes are installed, tubes filled with liquid through which heat exchange occurs.
The liquid circulates through the closed circuit, descends, heats or cools and rises again, activating a pump. When this happens, the surrounding medium loses its temperature to transfer it to the system used for heating inside the house, which can be air or water. When it comes back down, it takes the energy from the underground to take it back to the building. In this way, the continuous exchange that allows air conditioning occurs.
There are also horizontal circuits, in them the pipes are installed only one and a half meters deep. For this system it is necessary to have a large piece of land with a plant cover and a good contribution of solar radiation. The extension of the circuit must be calculated considering the location of the building, the surface to be heated, the construction techniques and the characteristics of the terrain.
Advantages and disadvantages of geothermal air conditioning
Like all options for energy efficiency, geothermal air conditioning has advantages and disadvantages that must be considered when evaluating its implementation in a project. Below we list the main characteristics that it is advisable to analyze:
- Its operation is economical.
- It allows a certain level of energy independence.
- It produces very little waste and has a low environmental impact.
- It provides a constant flow of energy throughout the year.
- It is a renewable and inexhaustible energy.
- The installation is complex.
- It requires a large area.
- It is little developed in our country, so the initial investment in materials and installation is high.