The operation principle is based on the well-known surface discharge which can create ozone and hydroxyl radicals when humidified air is used as carrier gas. A long lifespan is granted by coated ceramics. Efficient deodorization and air refreshment saves energy costs in closed buildings and homes. Hygiene is increased in food storage premises. Fruits, vegetables and flowers can be stored and kept fresh for much longer, especially in lorries, containers, ships or planes.