Humidifiers
They are panels put on the walls (sometimes on the ceiling) of the farms in order to reduce the temperature. Water descends through them constantly and very slowly, through a cardboard or plastic framework. When hot air goes through this panel with water coming down through it, a great amount of water evaporates, and this causes an important decrease in the temperature of the air that comes in. The principle is the same as splashing a pig with water (when the water evaporates, the temperature of its skin goes down), but in this case, the evaporation is used to cool the air that enters the farm. This cold air will cool the animals down. Apart from reducing the temperature, these systems increase the environmental humidity.