The Case for a ventilation device Is the ideal solution for living space of approx. 40-80m², depending on the individual ventilation requirement. Heat exchanger: Cross current heat exchanger made of plastic with turbulent surface (200x200x160x2.4mm) We manufacture heat exchangers in every size according to your requirements. Let us know your desired air output and the required efficiency - we will make you an individual offer. Uniflex wall grille Central ventilation shell construction WRG ventilation system ventilation grille Distribution box DN75 200/15 Central living space ventilation shell construction distribution box KWL Uniflex wall grille Central ventilation shell construction WRG ventilation system ventilation grille Distribution box DN75 200/15 Central living space ventilation s.