DOUBLE-WALLED VENTILATING BUILDING UNITS FOR THE BUILDINGS WITH THE OVERPRESSURE VENTILATING OR CONDITIONING INSTALLATION

A double-wall facade element for buildings having an overpressure ventilating or air conditioning installation wherein at the region of a horizontal edge of the element there is provided at its inner wall a throughpassage opening for exhaust air and at the region of the other horizontal edge there is provided at its outer wall a blow-off or exhaust opening for the exhaust air, both openings being in flow communication with one another via an intermediate space or compartment between the inner wall and the outer wall. The flow cross-section of the throughpassage opening is greater than the flow cross-section of the blow-off or exhaust opening, but smaller than the flow cross-section of the intermediate compartment. Further, at the region of the exhaust opening there is arranged a check valve responsive to increasing external pressure in order to throttle its flow cross-section, so that in the intermediate compartment there can be adjusted a pressure gradient between the throughpassage opening and the blowoff or exhaust opening which is smaller than the difference between the water vapor partial pressure in the interior of the building and the water vapor partial pressure in the outside area in the presence of external temperatures which are lower in relation to the internal temperature.