Since 2010 the REGEL-air® window-ventilation systems are complemented by our REGEL-air® RF that can be fitted in the vertical window frame. Now it is possible to increase the air change with a flexible combination of all three REGEL-air® products: The REGEL-air® FL, REGEL-air® RF and the Überschlagslüfter (which is situated at the overlap of the casement). That enables the compliance of the ventilation requirements of DIN 1946-6 – from Feuchteschutzlüftung to Nennlüftung. The REGEL-air® RF reacts like the approved window-fold ventilator from REGEL-air® to changes of wind pressure around the building and is concealed in the window-fold. REGEL-air® can be used for requirements of DIN 1946-6 and combustion air.