Geothermal energy is a branch of geophysics that is dedicated to the study of the thermal conditions of the Earth. One of the applications of this study is to obtain energy, which is stored under the surface in the form of heat. Different uses that can be made of it are investigated, such as converting it into electrical energy, but one of the ones that gives the best results and is easier to carry out is the air conditioning of homes. Despite this, the energy stored under the Earth is one of the least known renewable energy sources.
Although the geothermal air conditioning system is based on taking advantage of the heat of the Earth, in reality it is not only used for heating in winter, but it is a regulating system that can also help keep environments cooler in summer. Using this system, a group of engineers from the University of Córdoba (Argentina) managed to maintain an environment at a constant temperature of 18ºC for a whole year.
The system used by the team of young civil engineers is known in the world as surface or low enthalpy geothermal energy, and consists of the installation of pipes or tubes placed in shallow excavations to function as heat exchangers. With the help of a fan, the tubes help to extract the warm air that accumulates underground in winter, and the cold air in summer.
This is possible because the temperature of the earth a few meters below the surface is usually always close to the annual average of the area, while above the surface, the temperature fluctuates more rapidly. In winter, the earth retains the heat of the solar radiation of summer, and in that season, the temperature of the dark subterranean redoubts is much lower than on the surface, in the sun’s rays.
The system designed by this team has already been tested with very good results in two homes in Córdoba; one located in the city and the other, in the Mayu Sumaj locality, in the Punilla Valley. The next step will be to test its operation in a building in Ciudad Universitaria. This technology ensures significant energy savings and is very low cost.
The method is not entirely new to the world; and in some European countries, as well as in the United States and Japan, a similar system is quite widespread, but with the difference that air does not circulate through the tubes, but water or another fluid; and this makes its cost much higher, due to the need for an electric pump that forces the circulation of the liquid.
The adoption of a simple but effective technique such as this could be an economic solution for the extreme conditions of cold and heat that are experienced in different parts of the world and that affect, above all, those who do not have the economic resources to obtain the systems of most common heating and cooling. All this without mentioning the damage that these systems, such as air conditioners, or stoves that use gas, a fossil fuel, do to the planet; and that with simpler systems like this could be avoided.