Proper ventilation of your pig stable is of great importance, but can be realised in several ways.
Central extraction is often used and works through a central extraction duct, which is connected to the air washer in most cases.
Extraction per room is also used on a regular basis.
The inlet of the air is just as important as the extraction in the stable . This can be done by means of an inlet curtain on the side of your stable.
Another widely used system are the Fancom inlet valves.