Fumus is always equipped with a fan in the lower part of the chimney. This fan 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 by means of a butterfly valve above the fan.
Depending on the position of the butterfly valve, anywhere between 100 percent fresh air (vertical position) and 100 percent 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 means that, depending on the ventilation requirements, the barn can be supplied with fresh air, mixed air or recirculated air.
For minimum ventilation (in the cold seasons or while heating is necessary), Fumus works with balanced pressure or slightly positive pressure. Fumus is available with the following diameters: 650, 730, 820 or 920 mm.