PART 3 - EXECUTION 3.1 APPLICATION AND INSTALLATION A. Install duct accessories according to applicable details in SMACNA's "HVAC Duct Construction and Flexible" for metal ducts and in NAIMA AH116, "Fibrous Glass Duct Construction Standards," for fibrous-glass ducts. B. Provide duct accessories of materials suited to duct materials; use accessories in galvanized-steel and fibrous-glass ducts, stainless-steel accessories in stainless-steel ducts, and aluminum accessories in aluminum ducts. C. Install backdraft dampers on exhaust fans or exhaust ducts nearest to outside and where indicated. D. Install volume dampers in with liner; avoid damage to and erosion of duct liner. E. Provide balancing dampers at points on supply, return, and exhaust systems where branches lead from larger ducts as required for air balancing. Install at a minimum of two duct widths from branch takeoff. F. Provide test holes at fan inlets and outlets and elsewhere as indicated. G. Install fire and dampers, with fusible links, according to manufacturer's UL- approved written instructions. H. Install duct silencers independent of ducts with flexible duct connectors, lagged with loaded vinyl sheet on inlets and outlets. I. Install duct access doors to allow for inspecting, adjusting, and maintaining accessories and terminal units as follows: 1. On both sides of duct coils. 2. Downstream from volume dampers, turning vanes, and equipment. 3. Adjacent to fire or smoke dampers, providing access to reset or reinstall fusible links. 4. To interior of ducts for cleaning; before and after each change in direction, at maximum 50-foot (15-m) spacing. 5. On sides of ducts where adequate clearance is available. J. Install the following sizes for duct-mounting, rectangular access doors: 1. One-Hand or Inspection Access: 8 by 5 inches (200 by 125 mm). 2. Two-Hand Access: 12 by 6 inches (300 by 150 mm).
PART 3 - EXECUTION 3.1 APPLICATION AND INSTALLATION A. Install duct accessories according to applicable details in SMACNA's "HVAC Duct Construction and Flexible" for metal ducts and in NAIMA AH116, "Fibrous Glass Duct Construction Standards," for fibrous-glass ducts. B. Provide duct accessories of materials suited to duct materials; use accessories in galvanized-steel and fibrous-glass ducts, stainless-steel accessories in stainless-steel ducts, and aluminum accessories in aluminum ducts. C. Install backdraft dampers on exhaust fans or exhaust ducts nearest to outside and where indicated. D. Install volume dampers in with liner; avoid damage to and erosion of duct liner. E. Provide balancing dampers at points on supply, return, and exhaust systems where branches lead from larger ducts as required for air balancing. Install at a minimum of two duct widths from branch takeoff. F. Provide test holes at fan inlets and outlets and elsewhere as indicated. G. Install fire and dampers, with fusible links, according to manufacturer's UL- approved written instructions. H. Install duct silencers independent of ducts with flexible duct connectors, lagged with loaded vinyl sheet on inlets and outlets. I. Install duct access doors to allow for inspecting, adjusting, and maintaining accessories and terminal units as follows: 1. On both sides of duct coils. 2. Downstream from volume dampers, turning vanes, and equipment. 3. Adjacent to fire or smoke dampers, providing access to reset or reinstall fusible links. 4. To interior of ducts for cleaning; before and after each change in direction, at maximum 50-foot (15-m) spacing. 5. On sides of ducts where adequate clearance is available. J. Install the following sizes for duct-mounting, rectangular access doors: 1. One-Hand or Inspection Access: 8 by 5 inches (200 by 125 mm). 2. Two-Hand Access: 12 by 6 inches (300 by 150 mm).