Cubic ventilation box with low-loss pipe connection nozzles on the pressure and suction side including flexible sleeves to prevent structure-borne noise and variably usable housing panels for optimal adaptation to structural conditions. Easy positioning thanks to standard crane hooks. Self-supporting housing frame construction made of aluminum hollow profiles. Double-walled, 20 mm thick side panels made of galvanized sheet steel, sound and heat insulated by lining with non-flammable mineral wool. The housing panels can be replaced as required with accessories such as weather protection grilles and condensate trays. Additional accessories, wall bracket and weather protection roof can be mounted inside and outside for any installation. High-performance radial impeller made of steel with backwards curved blades on a galvanized steel disk, directly driven. Vibration-free operation due to dynamic balancing together with the motor in accordance with quality level 6.3 according to DIN ISO 1940 T.1. Driven by single-phase AC external rotor motor, closed, maintenance-free design, speed can be controlled by reducing the voltage, built-in thermal contacts wired in series with the winding, self-resetting, sealed, low-noise ball bearings with long-term lubrication. Mains connection on the terminal box integrated in the device (IP54).