86 may be cast or sheet metal plastic reinforced plastic composite or other appropriate material motorized impeller 36 is secured to mounting plate 86 which plate may be configured so that different sizes of motorized impeller 32 may be attached to it and used with the air cleaner of this invention additionally other mounting components may be used with larger or smaller or differently configured motorized impellers as is easily seen in fig8 a control panel 16 is attached to the upper portion of cover 36 in a sloping orientation making it easy to see and readily accessible panel 16 is mounted between two ribs 37 that protrude from outlet cover 36 above the panel 16 and protect the panel and relatively delicate components on it from inadvertent damaging contact that might otherwise occur during transportation or use of the unit 10 particularly in building remediation or construction environments of the sort in which air filtration units are used the panel 16 can carry various components including switches and other controls indicator lamps outlets power cords and any other appropriate devices portions of such devices on the inside of panel 16 are housed within and isolated from cavity 72 by a box 38 that may be a rectilinear box as depicted in the drawings or any other appropriate shape of metal plastic or other appropriate material the lower portion of cover 36 is penetrated by a large round opening 88 providing the air exhaust 18 attached to the cover 36 around the opening 88 protruding outside the cover 36 is a short cylindrical tube 90 through which filtered air is exhausted a grill 92 positioned within tube 90 blocks access to.