Features and Construction: The Rosenberg roof fans are used for ventilation of department stores, supermarkets, factories, swimming pools, kitchens, dining halls, warehouses, garages, farms and stables. The fans are suitable for mounting on a flat or any shaped roof. There are different types of roof units: Type DH with horizontal discharge for less polluted air Type DV with vertical discharge for heavily contaminated air. Can be supplied as swing-out version on request.