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 - 4 6.Variable frequency drives shall be factory wired and mounted in the unit.Fan motors shall be premium efficiency. H.Cooling Coils 1.DX Evaporator Coils a.Coil shall be rated in accordance to AHRI standards,designed to withstand 250 psig working pressure at 300 degrees F,and pressure tested to 600 psig. b.Coils shall be designed for use with R-410A refrigerant and constructed of copper tubes with aluminum fins mechanically bonded to the tubes and galvanized steel end casings. Fin design shall be sine wave rippled. c.Coils shall have interlaced circuitry and shall be standard capacity. d.Coils shall have interlaced circuitry and shall be minimum 6 row high capacity. e.Coils shall be hydrogen or helium leak tested. f.Coils shall be furnished with factory installed expansion valves. I.Hydronic Heating Coil (Reheat Position) 1.Unit shall be provided with AHRI rated hot water coil. a.Coil casing shall be constructed of 16 gage galvanized steel casing. b.Coil tubes shall be constructed of 1/2"diameter,0.016"thick seamless copper tubing. c.Coil shall be rated in accordance to AHRI standards,designed to withstand 250 psig working pressure at 300 degrees F,and pressure tested to 450 psig. d.Coil fins shall be constructed of 0.0060"thick aluminum fins. e.Coil shall be hydrogen or helium leak tested. 2.Unit shall include an insulated vestibule for piping hot water connections inside the unit. 3.Piping shall be provided by others in the field. 4.Control valve shall be provided by others in the field. 5.Unit controller shall provide a 0-10 VDC signal to operate field-provided control valve. J.Hot Gas Reheat Coil 1.Hot-gas reheat coil shall be separated from the evaporator coil by a minimum of 6”in the direction of airflow to prevent the re-evaporation of condensate,provide room for coil cleaning,and allow control system to monitor evaporator coil leaving dew point temperature. 2.Coil shall be rated in accordance to AHRI standards,designed to withstand 250 psig working pressure at 300 degrees F,and pressure tested to 600 psig. 3.Coil casing shall be constructed of 16 gage galvanized steel or 304 stainless steel. 4.Coil tubes shall be constructed of 5/16"diameter,0.012"thick seamless copper tubing. 5.Coil fins shall be constructed of 0.0060"thick aluminum fins. 6.Hot-gas reheat shall be controlled through a factory-supplied and controlled modulating 3- way valve. 7.Coil shall be hydrogen or helium leak tested. K.Refrigeration System 1.Unit shall be factory charged with R-410A refrigerant. 2.Compressors shall be scroll type with thermal overload protection and carry a 5 year non- prorated warranty,from the date of original equipment shipment from the factory. 3.Compressors shall be mounted in an isolated service compartment which can be accessed without affecting unit operation.Lockable hinged compressor access doors shall be fabricated of double wall,rigid polyurethane foam injected panels to prevent the transmission of noise outside the cabinet. 4.Compressors shall be isolated from the base pan with the compressor manufacturer’s recommended rubber vibration isolators,to reduce any transmission of noise from the compressors into the building area. 5.Each refrigeration circuit shall be equipped with expansion valve type refrigerant flow control. 6.Each refrigeration circuit shall be equipped with automatic reset low pressure and manual reset high pressure refrigerant safety controls,Schrader type service fittings on both the high pressure and low pressure sides and a factory installed replaceable core liquid line filter driers. 7.Unit shall include a variable capacity scroll compressor on the lead refrigeration circuit which shall be capable of modulation from 10-100%of its capacity. DocuSign Envelope ID: 94E7997D-4F29-42F6-A9B4-0A160438D2A6