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DocuSign Envelope ID: 9826C043- 4C32- 49CD- A4CC- DC28ABAB7CE7 <br />G. <br />Service <br />Types <br />SECTION 238100 - HVAC INSULATION <br />seams and joints for vapor tight installation. For elastomeric insulation, apply full bed of adhesive to <br />both surfaces. For polyeolefin, seal factory preglued seams with roller and field seams and joints with <br />full bed of hot melt polyolefin glue to both surfaces. Cover elastomeric insulation on systems <br />operating below 40 degrees F with vapor barrier mastic. <br />EXTRUDED POLYSTYRENE AND POLYISOCYANURATE: Secure insulation sections with two <br />wraps of nylon filament tape 9 " -12" on center. On single insulation layer systems and on the outer <br />layer of double insulation layer systems, apply a thin coat of elastomeric joint sealant rated for <br />system operating temperatures to all longitudinal and butt insulation joints covering entire face of <br />joint. Allow sealant to fully cure before applying protective covering. For piping service below 0 °F, use <br />two layers of insulation with inner and outer butt and longitudinal joints staggered and offset 90 <br />degrees. Where two layers of insulation are used, do not use sealant on the inner layer or adhere the <br />inner layer to the outer layer. Fill voids in factory molded or built -up valve and fitting insulation with <br />foamed in place urethane insulation. Apply vapor stop bead of joint sealant between pipe and <br />insulation on both sides of valves, expansion /contraction joints, flanges, thermometers /gauges, <br />attached vent and drain lines. Insulate attached non - circulated lines, control lines, vents, etc. for a <br />minimum distance of 6" from pipe. Cover insulation with a protective covering of 2 coats of vapor <br />barrier mastic with fabric reinforcing. Do not penetrate protective covering or insulation with <br />mechanical fasteners. <br />PIPE INSULATION SCHEDULE: <br />1. Provide insulation on new and existing remodeled piping as indicated in the following <br />schedule: <br />Insulation Insulation Thickness by Pipe Size <br />Refrigerant Elastomeric <br />(Both Discharge and Suction) <br />Copper Condensate Elastomeric <br />1" and 1 -1/4" 2 -1/2" 5" to 6" 8" and <br />smaller to 2" to 4" larger <br />1" 1" 1" <br />1" 1" 1" 1" 1" <br />3.3 DUCT INSULATION <br />A. General: <br />1. Secure flexible duct insulation on sides and bottom of ductwork over 24" wide and all rigid <br />duct insulation with weld pins or speed clips. Space fasteners 18" on center or less as <br />required to prevent sagging for flexible duct insulation. Space fasteners not less than 3" from <br />edge or corner and 12" on center or less for rigid duct insulation. Install weld pins without <br />damage to the interior galvanized surface of the duct. Clip pins back to washer and cover <br />penetrations with tape of same material as jacket. Firmly butt seams and joints and cover with <br />4" tape of same material as jacket. Seal tape with plastic applicator and secure with staples. <br />All joints, seams, edges and penetrations to be fully vapor sealed. <br />2. Stop and point insulation around access doors and damper operators to allow operation <br />without disturbing insulation or jacket material. <br />3. External supply duct insulation is not required where ductwork contains continuous 1" <br />acoustical liner. Provide 4" overlap of external insulation over ends of acoustically lined <br />sections. <br />B. GREASE DUCTS: Strictly adhere to manufacturer's installation instructions and rating requirements <br />for application of fire -stop insulation. Cover all exhaust ducts serving Type I kitchen hoods with fire - <br />stop insulation from a point prior to penetration of ceiling, wall, floor or concealment through building <br />to termination at outside of building. Extend fire -stop insulation through roof curbs. <br />C. Duct Insulation Schedule: <br />1. Provide duct insulation on new and existing remodeled ductwork in the following schedule: <br />Service Insulation Type Insulation Thickness <br />Outside air ducts (to hru's and ahu's) Flex. / Rigid Fiberglass 2" <br />Mixed air ducts Flex. / Rigid Fiberglass 2" <br />Exposed supply ducts* Flex. / Rigid Fiberglass 2" <br />Concealed supply / return ducts Flex. / Rigid Fiberglass 2" <br />Exhaust and relief ducts downstream (uninsulated) <br />of motorized backdraft dampers <br />All ducts exposed to weather Rigid Fiberglass 3" <br />Exhaust ducts to / from Flex. / Rigid Fiberglass 2" (from 20' from unit only) <br />of heat recovery units and dessicant dryers <br />Grease ducts serving Type I Fire -Stop As Req'd. for Specified <br />Kitchen hoods Hourly Rating <br />Exposed supply main and branch ducts located in the space they are serving do not require insulation. Ex- <br />posed supply main ducts running through spaces they serve shall be insulated as exposed supply ducts <br />scheduled above. <br />3.4 EQUIPMENT INSULATION <br />A. GENERAL:Do not insulate over equipment access manholes, fittings, nameplates or ASME stamps. <br />Bevel and seal insulation at these locations. <br />Reece, Noland & McElrath, Inc. 238100-4 Orange County Board of Elections <br />Orange Co., NC 05/04/18 <br />