2021-414-E-AMS-Riggs-Harrod Builders, Inc-SHSC Roof & HVAC Replacement

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Southern Human Services Center Smith Sinnett /2020072 HVAC and Roof Renovations Orange County,North Carolina VAV PACKAGED DX RTU 23 74 00 - 3 pressure,to reduce air leakage.Deflection shall be measured at the midpoint of the panel height and width.Continuous sealing shall be included between panels and between access doors and openings to reduce air leakage.Piping and electrical conduit through cabinet panels shall include sealing to reduce air leakage. 5.Roof of the air tunnel shall be sloped to provide complete drainage.Cabinet shall have rain break overhangs above access doors. 6.Access to filters,dampers,cooling coils,reheat coil,exhaust fans,energy recovery wheels, compressors,and electrical and controls components shall be through hinged access doors with quarter turn,zinc cast,lockable handles.Full length stainless steel piano hinges shall be included on the doors. 7.Exterior paint finish shall be capable of withstanding at least 2,500 hours,with no visible corrosive effects,when tested in a salt spray and fog atmosphere in accordance with ASTM B 117-95 test procedure. 8.Units with cooling coils shall include double sloped 304 stainless steel drain pans. 9.Unit shall be provided with horizontal discharge and return air openings.All openings through the base pan of the unit shall have upturned flanges of at least 1/2 inch in height around the opening. 10.Unit shall include lifting lugs on the top of the unit. D.Electrical 1.Unit shall be provided with factory installed and factory wired,non-fused disconnect switch. 2.Unit shall be provided with a factory installed and factory wired 115V,12 amp GFI outlet disconnect switch in the unit control panel. 3.Unit shall be provided with phase and brown out protection which shuts down all motors in the unit if the electrical phases are more than 10%out of balance on voltage,the voltage is more than 10%under design voltage or on phase reversal. E.Motorized Dampers 1.Frame shall be constructed of a 16 gage galvanized steel hat-channel. 2.Blades shall be constructed of 16 gage galvanized steel strengthened by three longitudinal 1 inch deep “vee”grooves. 3.Blades shall be symmetrical relative to its axle pivot point. 4.Axle bearings shall be synthetic sleeve-type and rotate inside extruded holes in the damper frame. 5.Blade seals shall be extruded vinyl permanently bonded to the appropriate blade edges. 6.Frame shall include flexible stainless steel compression-type jamb seals. 7.Modulating spring-return actuators shall be provided by the factory,installed on the damper, and wired to the control center. Each damper shall have a dedicated actuator.Single actuators with gear trains are not acceptable. 8.Damper leakage shall be no more than 3 cfm/sq.ft.at 1 in.wg static pressure. F.Supply Fans (VFD) 1.Unit shall include direct drive,unhoused,backward curved,plenum supply fans. 2.Blowers and motors shall be dynamically balance and mounted on rubber isolators. 3.Motors shall be premium efficiency ODP with ball bearings rated for 200,000 hours service with external lubrication points. 4.Variable frequency drives shall be factory wired and mounted in the unit.Fan motors shall be premium efficiency. 5.Fan wheel shall be tested in accordance to AMCA 210. G.Exhaust Fans (VFD) 1.Exhaust dampers shall be sized for 100%relief. 2.Fans and motors shall be dynamically balanced. 3.Motors shall be premium efficiency ODP with ball bearings rated for 200,000 hours service with external lubrication points. 4.Access to exhaust fans shall be through double wall,hinged access doors with quarter turn lockable handles. 5.Unit shall include direct drive or belt driven,unhoused,backward curved,plenum exhaust fans. DocuSign Envelope ID: 94E7997D-4F29-42F6-A9B4-0A160438D2A6