When the fan is activated, the return flap used in the air intake opens as a result of generated pressure difference and remains in this position, until the fan is deactivated. The flap opening force can be adjusted. Air intakes are additionally equipped with protection metal grille preventing larger impurities from
entering ventilated areas. The air intake housing is made of the ABS material, while the return flap is made of polystyrene.
The MAXI air intakes are properly shaped so that the air is sucked from the bottom preventing rain drops or snow from entering the installation. When selecting locations for air intakes, make sure they are placed:
- at the northern or eastern side of a building,
- not in the direct vicinity of air polluting agents, such as dustbins, workshops, vent air outlets.
Air inlet velocity to the air intake opening should amount to approximately 3 [m/s]. Higher velocities can produce additional noise and higher pressure losses. Using given recommended velocities and dimensions of air intake entry opening, that is 0,2 x 0,5 [m], a proper and recommended fan output cooperating with the air intake can be selected. The outputs should range from 1100 to 1800 [m//h]. The required pressure difference, at which the flap is fully open, can be adjusted and ranges from 25 to 40 [Pa] (the difference between air atmospheric pressure and pressure below atmospheric in a room). The air intakes are equipped with a sliding front panel for closing the intake (e.g. in winter season).