RAKU roof area fan
To prevent damage to wooden and metal parts and insulation due to structural moisture and moisture from use, heat-insulated roofs require sufficient aeration. For this purpose, aeration openings must be provided at the lowest point and ventilation openings at the highest. Here, the RAKU roof ventilation product range offers a variety of design possibilities.
For slate, fibrated cement plate or bitumen shingle roof cladding types
RAKU trapezoid, bull’s-eye and pitched dormer fans
RAKU DD fans
RAKU roof ridge fans
For standing or batten seam roof cladding types
RAKU trapezoidal, bull’s-eye and pitched dormer hoods of the Akropolis [Acropolis] roof ridge ventilation system
For bitumen or film sheet roof cladding types
Akropolis roof ridge ventilation system
Calculation of the ventilation cross-section
Air layers between the aerated roofs must be connected to the outdoor air. A sufficient dimensioning of the aeration and ventilation openings and the height of the ventilation space must be taken into consideration during planning. Fundamentally, aeration openings must be provided at the lowest point of the roof structure and ventilation openings at the highest.
Minimum ventilation cross-sections:
for roofs with a roof slope starting at 5° according to DIN 4108-3
Eaves and monopitch roof end piece:
0.2% of the pertinent roof area, but at least 200 cm²/m
Roof ridge and hip:
0.05 % of the pertinent roof area, but at least 50 cm²/m
Roof area:
The roof area must have a clear height of 2 cm; the barrier value below the aeration level amounts to ≥ 2 m.
Protection against snow and rain
Continuous base plate, inner ventilation hole arranged at a higher position and, if desired, additional protective plates combine to form effective protection against snow and rain.
Active ventilation
The RAKU Aktiv [Active] roof ridge fan is designed in such a way that a suction effect arises inside the fan due to wind. This suction effect extracts the air right out of the rear section of the roof space being ventilated.
This results in a multiplication of the ventilation cross-section. As a positive side effect, the penetration of driving rain and blowing snow from strong wind in particular is prevented due to the counterpressure.
Penetrating rainwater is conducted away from the fan through the two-chamber system.