There are three types of ventilation systems. All of them are aimed at creating comfortable conditions. The first option. Air comes in naturally, and the exhaust is forced. Exhaust ducts are located in the kitchen, bathroom, utility room and are equipped with adjustable dampers. Fresh air is supplied through supply wall or window ducts. The advantage is the absence of noise. The disadvantage is the need for high-quality filters that effectively trap dust. The second option is exhaust ventilation of cottages. In some cases, the system can process the heat of the exhaust air and use it for its own purposes. A distinctive feature is that one system supplies and takes air. The air extracted from the street is cleaned and heated if necessary. After this, the air masses are sent to the desired rooms through ceiling lamps. Heating occurs with the help of a plastic recuperator. The third option is a combination of ventilation and air conditioning systems. In this case, 2 units are installed: one outside, the other inside. This variation is considered the most convenient due to its versatility.