The company Venta-Luftwascher offers a fifth generation of the airwashers series LW15, LW25, LW45 with a worldwide unique technology. The airwasher works without filter pads. Dry indoor air is drawn into the appliance and passes through the disk stacks rotating in water. The air is literally washed. Impurities in the air, stale tobacco smoke, household dust, pollen and allergens are trapped in the water. Only clean, humidified air evaporates. The Venta-Airwasher works on the principle of natural evaporation which is widely recognized as the best method of humidification. No ions, no ozone, no white dust; will not over-humidify.