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Southern Human Services Center Smith Sinnett /2020072 <br />HVAC and Roof Renovations Orange County,North Carolina <br />HVAC Power Ventilators 23 34 23 - 2 <br />D.Fabrication: Comply with AMCA 99. <br />E.UL Compliance: UL listed and labeled,designed,manufactured,and tested in accordance with UL <br />705. <br />F.Electrical Components: Listed and classified by Underwriters Laboratories Inc.as suitable for the <br />purpose specified and indicated. <br />G.Enclosed Safety Switches: Comply with NEMA 250. <br />2.03 ROOF EXHAUSTERS <br />A.Fan Unit: V-belt or direct driven as indicated,with spun aluminum housing;resilient mounted <br />motor;1/2 inch mesh,0.62 inch thick aluminum wire birdscreen;square base to suit roof curb with <br />continuous curb gaskets. <br />B.Roof Curb: ​24 inch​high​self-flashing​of ​galvanized steel​with continuously welded seams,​built-in <br />cant strips,insulation and curb bottom,and factory installed nailer strip​. <br />C.Disconnect Switch: Factory wired,non-fusible,in housing for thermal overload protected motorand <br />wall mounted solid state speed controller or EC motor,refer to fan schedule.. <br />D.Backdraft Damper: Gravity actuated,aluminum multiple blade construction,felt edged with offset <br />hinge pin,nylon bearings,blades linked. <br />E.Sheaves: Cast iron or steel,dynamically balanced,bored to fit shafts and keyed;variable and <br />adjustable pitch motor sheave selected so required rpm is obtained with sheaves set at mid- <br />position;fan shaft with self-aligning pre-lubricated ball bearings. <br />PART 3 EXECUTION <br />3.01 INSTALLATION <br />A.Install in accordance with manufacturer's instructions. <br />B.Secure roof exhausters with cadmium plated steel lag screws to roof curb. <br />C.Extend ducts to roof exhausters into roof curb. Counterflash duct to roof opening. <br />D.Provide sheaves required for final air balance. <br />E.Install backdraft dampers on inlet to roof and wall exhausters. <br />F.Provide backdraft dampers on outlet from cabinet and ceiling exhauster fans and as indicated. <br />END OF SECTION <br />DocuSign Envelope ID: 94E7997D-4F29-42F6-A9B4-0A160438D2A6