The France Air BVX 3 filtering ceiling is a very simple and reliable filter tightening system. The airtightness is maintained by placing plenum and filters. The Norm NFS 90-351 describes diffusion grille generating, protection of the whole surface and a uni-directional flow of air. The 7 standard dimensions used from 1390 x 1330 to 2975 x 2060, supplied airflow from 1330 m3/h to 8000 m3/h, a standard height of 450 mm., a filtration V.H.E. of H14 or U15 in standard heights or thickness of 68 mm. The filtering ceiling with uni-directional flow enables obtaining of ISO 5 according to EN ISO 14644-1 for rate required renewal. This is widely used in sterile rooms, aseptic bedclothes, hospital and pharmaceutical industries. The wall version of BVX 3 has horizontal flow.