Air humidifier quiet series stadler form oskar power 18 watt power consumption in use 18 watt room size 50 m maximum room size 125 m humidifying capacity 88 l24 h water tank 35 litres power settings 2 max noise emission 39 db operation cold evaporation features humidistat filter system humidifying filter safety features automatic shut off filter change indicator material plastic dimensions 29 x 246 x 246 cm weight 31 kg