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DocuSign Envelope ID: 9826C043- 4C32- 49CD- A4CC- DC28ABAB7CE7 <br />SECTION 239150 - AIR DUCT ACCESSORIES <br />2.9 DUCT ACCESSORY HARDWARE <br />A. Instrument Test Holes: Cast iron or cast aluminum to suit duct material, including screw cap and <br />gasket. Size to allow insertion of pitot tube and other testing instruments and of length to suit duct - <br />insulation thickness. <br />B. Adhesives: High strength, quick setting, neoprene based, waterproof, and resistant to gasoline and <br />grease. <br />PART 3 - EXECUTION <br />3.1 INSTALLATION <br />A. Install duct accessories according to applicable details in SMACNA's "HVAC Duct Construction <br />Standards - Metal and Flexible" for metal ducts and in NAIMA AH116, "Fibrous Glass Duct <br />Construction Standards," for fibrous -glass ducts. <br />B. Install duct accessories of materials suited to duct materials; use galvanized -steel accessories in <br />galvanized -steel and fibrous -glass ducts, stainless -steel accessories in stainless -steel ducts, and <br />aluminum accessories in aluminum ducts. <br />C. Install backdraft dampers at inlet of exhaust fans or exhaust ducts as close as possible to exhaust <br />fan unless otherwise indicated. <br />D. Install volume dampers at points on supply, return, and exhaust systems where branches extend <br />from larger ducts. Where dampers are installed in ducts having duct liner, install dampers with hat <br />channels of same depth as liner, and terminate liner with nosing at hat channel. <br />1. Install steel volume dampers in steel ducts. <br />2. Install aluminum volume dampers in aluminum ducts. <br />E. Set dampers to fully open position before testing, adjusting, and balancing. <br />F. Install test holes at fan inlets and outlets and elsewhere as indicated. <br />G. Install fire and smoke dampers according to UL listing. <br />H. Install duct access doors on sides of ducts to allow for inspecting, adjusting, and maintaining <br />accessories and equipment at the following locations: <br />1. On both sides of duct coils. <br />2. Downstream from manual volume dampers, control dampers, and equipment. <br />3. Adjacent to and close enough to fire or smoke dampers, to reset or reinstall fusible links. <br />Access doors for access to fire or smoke dampers having fusible links shall be pressure relief <br />access doors; and shall be outward operation for access doors installed upstream from <br />dampers and inward operation for access doors installed downstream from dampers. <br />4. At each change in direction and at maximum 50 -foot spacing. <br />5. Upstream of turning vanes. <br />6. Elsewhere as indicated. <br />I. Install access doors with swing against duct static pressure. <br />J. Access Door Sizes: <br />1. One -Hand or Inspection Access: 8 by 5 inches. <br />2. Two -Hand Access: 12 by 6 inches. <br />3. Head and Hand Access: 18 by 10 inches. <br />4. Head and Shoulders Access: 21 by 14 inches. <br />5. Body Access: 25 by 14 inches. <br />6. Body plus Ladder Access: 25 by 17 inches. <br />K. Label access doors according to Division 23 Section "Identification for HVAC Piping and Equipment" <br />to indicate the purpose of access door. <br />L. Install flexible connectors to connect ducts to equipment. <br />M. For fans developing static pressures of 5 -inch wg and more, cover flexible connectors with loaded <br />vinyl sheet held in place with metal straps. <br />N. Connect terminal units to supply ducts directly or with maximum 12 -inch lengths of flexible duct. Do <br />not use flexible ducts to change directions. <br />O. Connect diffusers or light troffer boots to low- pressure ducts directly or with maximum 60 -inch lengths <br />of flexible duct clamped or strapped in place. <br />P. Connect flexible ducts to metal ducts with adhesive plus sheet metal screws. <br />Q. Install duct test holes where required for testing and balancing purposes. <br />R. Install thrust limits at centerline of thrust, symmetrical on both sides of equipment. Attach thrust limits <br />at centerline of thrust and adjust to a maximum of 1/4 -inch movement during start and stop of fans. <br />3.2 FIELD QUALITY CONTROL <br />A. Tests and Inspections: <br />1. Operate dampers to verify full range of movement. <br />2. Inspect locations of access doors and verify that purpose of access door can be performed. <br />3. Operate fire and smoke dampers to verify full range of movement and verify that proper heat - <br />response device is installed. <br />4. Inspect turning vanes for proper and secure installation. <br />END OF SECTION 239150 <br />Reece, Noland & McElrath, Inc. 239150-3 Orange County Board of Elections <br />Orange Co., NC 05/04/18 <br />