Fumus is equipped with a fan in the lower part of the chimney, which pushes the fresh air drawn in by the chimney through the fresh air distributor and into the barn. The amount of air entering the barn is regulated using a butterfly valve above the fan.
Depending on the position of the butterfly valve, anywhere between 100% fresh air (vertical position) and 100% recirculated air (horizontal position) enter the barn. Between these positions, a certain amount of fresh air is mixed with the house air, which is drawn in through the 10 cm wide opening at the chimney. This allows the barn to be supplied with fresh air, mixed air or recirculated air, depending on ventilation requirements.
For minimum ventilation (in the cold seasons or while heating is necessary), Fumus works with balanced pressure or slightly positive pressure.