External louvres and caps in the HVAC ventilation system
Louvers are very simular to dampers, except that the slats or vanes are manufactured at a fixed non-adjustable angle. Louvers are normally installed into a wall or other location to provide positive ventilation for a room or enclodes area. Louvers are available in all shapes, sizes and flow capatibilities. Typically, louvers are made from sheet metal. Materials typically used are aluminum,or galvanized steel. A louver (American English) or louvre (British English) is a window blind or shutter with horizontal/vertical slats that are angled to admit light and air, but to keep out rain and direct sunshine. The angle of the slats may be adjustable, usually in blinds and windows, or fixed.