The plenum box DP100 is used for installation with square or rectangular diffusers and grilles. Both fixed mounting and central screw fixing possible. For an even air pattern through the diffuser, the plenum can be equipped with a perforated diffusor plate. Flow control is possible because of a perforated damper in the inlet spigot of the plenum. The plenum can be delivered with side or top entry, insulated plenum boxes can be supplied if required.