designed for rooms with special requirements (computer centres, libraries, and archives) Description The diffuser backside is provided with a filter housing designed for the installation of a filter. The filter consists of a classic filter insert of a 200mm thickness, to be replaced when the pressure drop due to congestion increases. The filter is of the EU 3 quality class. The initial pressure drop caused by the filter, at the volume flow of 500 m3/h and the velocity in the diffuser vef=1.4 m/s, equals to 50 Pa. Installation The diffuser is designed for the installation in raster ceiling structures with 600 x 600 partitions.