The compact ventilation unit LG 350 and LG 450 comprise a compact thermally insulated EPP housing without thermal bridges, of galvanized sheet steel, externally powder-coated in RAL 9010. They have a highly efficient heat recovery system with an air/air counterflow heat exchanger made of recyclable plastic, with automatic 100% bypass and energy-saving radial fans driven by the latest EC motor technology. The integrated air flow rate measurement guarantees balanced operation on the supply and extract air sides. The standard air filters used for extract air are of quality class ISO ePM1 70% and for outdoor air of quality class ISO Coarse 80%. The operation is simple and intuitive via the MINI or TOUCH (optional) control unit and with connection to the Internet (LAN connection) via the Pichler app. The optional expansion options for the CO2 sensor module and the humidity sensor allow for demand-driven ventilation operation. The compact ventilation units LG 350 and LG 450 are suitable for floor or wall mounting in frost-free rooms.