A abstract an air filtering and distribution system includes a first planar section hung from the ceiling of an enclosure which includes air filter modules light modules and blank filler panels a second planar section spaced from and hung below and generally parallel to the first planar section houses a plurality of membrane diffusion panels for uniformly distributing air through an enclosure without turbulence the membrane diffusion panels are composed of a fibrous filter panel mounted on a grid shaped ceiling panel application_number US 73555085 A description referring to fig1 the membrane diffusion panel 10 of the present invention comprises ceiling panel 12 preferably a polystyrene ceiling panel comprising 70 to 80 percent open area ceiling panel 12 is preferably translucent to allow lighting fixtures affixed thereabove to provide adequate illumination for the clean air work area as shown in fig1 ceiling panel 12 may take the form of a grid having substantially parallel longitudinal and lateral bars defining apertures therebetween a fiber sheet 14 is mounted onto ceiling panel 12 retainer clips 16 preferably composed of an extruded plastic secure fiber sheet 14 to ceiling panel 12 to comprise the membrane diffusion panel 10 fiber sheet 14 includes a clip 18 along its edges to provide assurance against unfiltered air leaking past the edges of the fiber sheet fiber sheet 14 preferably comprises a translucent spunbound polyester structure.