Furnish and install Anemostat Model PD-L, PD-F, PD-C, PD-T, PD-D, PDX-L, PDX-F, PDX-C, PDX-T, or PDX-D perforated supply diffusers to match ceiling system type located as shown on plans. The diffusers shall have a nominal 24” x 24” drawn back pan with a square or round neck for supply duct connection, and shall include earthquake loops. Pattern control vanes shall be attached to the back pan and shall be configurable in the field for a 1, 2, 3, or 4 way side or diagonal air pattern. Deflectors or vanes attached directly to the perforated face are not approved. Pattern adjustment shall be made by removing, rotating, and reattaching the vanes to the back pan. Diffusers requiring closure of louvers/vanes or utilizing blank-offs for pattern adjustment are not approved. (Optional) Volume dampers shall be located in the neck of the diffuser for balancing. The perforated face plate shall be constructed of minimum 22 gauge steel with not less than a 50% free area pattern. Face plates of expanded metal or directional louvers formed out of the face material are not approved. The face plate shall be removable from the back pan by concealed spring clips. The face shall lie in the same plane as the bottom surface of the ceiling in which it is mounted (exception is surface mounted Model PFD and PFD-X). The complete unit shall be finished white, including face, backpan, and controllers.

RETURN UNITS
Furnish and install Anemostat Type 3RPLD, 3RPFD, 3RPCD, 3RPTD, or 3RPMD perforated returns to match perforated supply diffusers. Construction and finish shall be identical to the perforated supply diffusers (without pattern control vanes).