VentoVind PRO Special user manual
© Corroventa Avfuktning AB
2020.12
14 (39)
Vents and Dampers
Inlet and outlet vents must have satisfactory capacity in order to achieve the correct air flows and
pressure ratio. The recommended size of the inlet vent is a diameter that is at least as large as the
supply air fan's duct. In simpler attics, that consist of a single space, the air is most easily taken in at
one end and evacuated at the other. The inlet vent is then equal in size to the outlet vent. For larger
attics, you should use several outlet vents to distribute the air flow throughout the attic space. The
size of the inlet vent is then not the same as the outlet vent because you want to distribute incoming
air to two or more outlet vents by creating a small overpressure in the attic space. The size of the
vents is determined by the air volume that is to pass through the attic space.
For more complex attics that are divided up into multiple areas, you must ensure that the air can
pass freely between the areas. It is important to control the air streams without creating
counterpressure in the flow, this is to achieve optimum through-flow and drying out in the entire
cold attic space. See images 1
–
3.
•
Inlets and outlets can also occur through roof hoods. Roof hoods, which are purchased
separately from alternative suppliers and installed in accordance with their instructions.
•
Avoid using insufficiently large vents with gills or insect net equipped vents as these are very
likely to cause whistling sounds when the fan operates at full power.
When installing in large attic spaces, the location of the inlet and outlet vents are projected on the
building drawing in consultation with a specialist.
Sealing cold attic spaces
How the attic is sealed is important as the VentoVind™
function works best the better sealed the
cold attic is against uncontrolled air exchange from outside or from the living space. This should of
course be done in different ways for different houses and house constructions. The idea is that all air
that ventilates the attic space should be controlled by the
VentoVind™
system, to create the best
conditions to keep the moisture levels down.
Even if the following instructions only give a general description of a smaller cold attic, the principle
is the same for large constructions. It is intended to give an understanding of what has to be
achieved and some of the relevant materials. If in doubt about what kind of material and which
principle is best suited for a specific house construction, consult a professional.