Did you know that ancient man used closed spaces in caves to preserve certain foods? And that these spaces had natural air inlets and outlets that allowed the miracle of refrigeration?... Do you want to know more?

From the most remote times, man used at an empirical level, the use of closed spaces that allowed certain foods to be preserved at a temperature lower than that of the environment. In general, these spaces were caverns that, by having natural air currents in and out, allowed for the miracle of conservation.
Another use of cold spaces in ancient times was carried out by the Egyptians by placing their grains on the banks of the Nile River, to preserve certain crops in times of drought. In pre-Columbian America, the Aztec emperors organized groups of individuals for their exclusive service, who carried out the task of bringing ice to the craters of non-active volcanoes, near the Valley of Mexico, for the conservation of their crops. This ice from snowy mountain glaciers was also used by the Greeks and Romans.

In the 19th century, artificial refrigeration was a product of industrialization. The current refrigerator is the result of more than a century of evolution. The construction of the first artificial refrigerator is attributed to the French engineer Carlos Tellier, in the year 1863, who, through a liquefaction system, managed to lower the temperature to -79 degrees Celsius. Two years later he created his first liquid ammonia gas circulation refrigeration machine, for the production of cold for domestic and industrial use. This invention, which transformed the modern world, was improved in 1865. Years later he built a liquid gas mechanical compression machine and installed it in the factory of the master chocolatier Menier in France.

After considering the above points, the question inevitably arises: why is the use of refrigeration more essential today than in ancient times? Perhaps it can be answered with the following explanation. Previously, the sun's rays fell on the Earth and were absorbed by the ground, since it was in its natural form. In today's cities, the use of asphalt and cement in general, and the spacing between the floors and the roofs of the houses, do not allow the heat of the sun's rays to be absorbed, but, on the contrary, make it rebound. When the heat rises, the density of the smoke-fog (smog) in the air stops it and bounces it back to the ground (greenhouse effect). This concentration of hot air is what makes the use of domestic refrigerators and air conditioners indispensable.