The article presents an up-to-date technical solution of the air dehumidification system for pig breeding premises. The analysis of the existing ventilation systems used in pig breeding is presented. The influence of microclimate parameters on pigs is considered. The required values of microclimate parameters make it possible to obtain maximum productivity from pigs, reduce feed consumption, and also reduce potentially dangerous diseases to a minimum. In turn, the microclimate also affects the pigsty and the equipment installed in it. Compliance with the required values of microclimate parameters is a difficult task, since for small farms the purchase of an air conditioning system is unaffordable. Therefore, it is necessary to develop and design systems that would be economically profitable. The main parameters of the microclimate that affect the productivity and health of pigs are temperature and relative humidity. These parameters affect animals both separately and in a complex. It is known that at high humidity, both high and low temperatures have a negative effect on the body of pigs. If the relative humidity is 85% or more, and the indoor air temperature is below 10 0C, then the animals gain less weight, but the feed consumption increases. To create and maintain a microclimate in a pigsty, it is necessary to design inexpensive and productive installations operating in automatic mode. By draining the air in the pigsty, with the help of natural cold, it is possible to increase the productivity of animals, as well as reduce energy consumption. An installation has been developed to maintain optimal relative humidity.