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DocuSign Envelope ID: 9826C043- 4C32- 49CD- A4CC- DC28ABAB7CE7
<br />SECTION 239150 - AIR DUCT ACCESSORIES
<br />indicated on the drawings. Damper fire rating to be compatible with the rating of the building
<br />assembly in which the damper is used.
<br />2.4 ACCESS DOORS
<br />A. Access door to be designed and constructed for the pressure class of the duct in which the door is to
<br />be installed. Doors in exposed areas shall be hinged type with cam sash lock. Hinges shall be steel
<br />full length continuous piano type. Doors in concealed spaces may be secured in place with cam
<br />sash latches. For both hinged and non hinged doors provide sufficient number of camp sash latches
<br />to provide air tight seal when door is closed. Do not use hinged doors in concealed spaces if this will
<br />restrict access. Use minimum 1" deep 24 gauge galvanized steel double wall access doors with
<br />minimum 24 gauge galvanized steel frames. For non - galvanized ductwork, use minimum 1" deep
<br />double wall access door with frame that shall use materials of construction identical to adjacent
<br />ductwork. Provide double neoprene gasket that shall provide seals from the frame to the door and
<br />frame to the duct. When access doors are installed in insulated ductwork or equipment provide
<br />insulated doors with insulation equivalent to what is provided for adjacent ductwork or equipment.
<br />Access doors constructed with sheet metal screw fasteners will not be accepted.
<br />B. Use insulated, 1 -1/2 hour UL 555 listed and labeled access doors in kitchen exhaust ducts.
<br />2.5 FLEXIBLE DUCT
<br />A. Manufacturers: Anco Products, Clevaflex, Thermaflex, Flexmaster or approved equal.
<br />B. Factory fabricated , UL 181 listed as a class 1 duct, and having a flame spread of 25 or less and a
<br />smoke developed rating of 50 or under in accordance with NFPA 90A.
<br />C. Suitable for pressures and temperatures involved but not less than a 180 °F service temperature and
<br />±2 inch pressure class, depending on the application.
<br />D. Duct to be composed of polyester film, aluminum laminate or woven and coated fiberglass fabric
<br />bonded permanently to corrosion resistant coated steel wire helix. Two -ply, laminated, and
<br />corrugated aluminum construction may also be used.
<br />E. Where duct is specified to be insulated, provide a minimum 1 inch fiberglass insulation blanket with
<br />maximum thermal conductance of 0.23 K (75 degrees F.) and vapor barrier jacket of polyethylene or
<br />metalized reinforced film laminate. Maximum perm rating of vapor barrier jacket to be 0.1 perm.
<br />2.6 DUCT FLEXIBLE CONNECTIONS
<br />A. Material to be fire retardant, be UL 214 listed, and meet the requirements of NFPA 90A.
<br />B. Connections to be a minimum of 3 inches wide, crimped into metal edging strip, and air tight.
<br />Connections to have adequate flexibility and width to allow for thermal expansion /contraction,
<br />vibration of connected equipment, and other movement.
<br />C. Use coated glass fiber fabric for all applications. Material for inside applications other than corrosive
<br />environments, fume exhaust, or kitchen exhaust to be double coated with neoprene, air and water
<br />tight, suitable for temperatures between -10 °F and 200 °F, and have a nominal weight of 30 ounces
<br />per square yard. Material used for outdoor applications other than corrosive environments, fume
<br />exhaust, or kitchen exhaust to be double coated with HypalonZ,air and water tight, suitable for
<br />temperatures between -10 °F and 250 °F, and have a nominal wight of 26 ounces per square yard.
<br />D. For corrosive environments or fume exhaust applications indoors or outdoors, use a material coated
<br />with Teflon that is air and water tight, suitable for temperatures between -20 °F and 500 °F, and has a
<br />nominal weight of 14 ounces per square yard.
<br />2.7 SOUND ATTENUATORS
<br />A. Manufacturers: Industrial Acoustics Company, Environmental Elements Corporation, Semco,
<br />Dynasonics, United McGill, Rink, or approved equal.
<br />B. Construct of a 22 gauge galvanized steel outer casing, and 26 gauge galvanized, perforated steel
<br />inner liner. Seams and joints of outer casing to be air tight.
<br />C. Fill annular space between outer casing and inner liner with acoustic fill that is inert, inorganic, and of
<br />a density sufficient to obtain the specified acoustic performance. Material must meet requirements
<br />of NFPA 90A with a flame spread index of 25 or less and smoke developed rating of 50 or less.
<br />D. Acoustical and aerodynamic performance is indicated on schedules on the drawings.
<br />2.8 HOODS FOR INTAKE AND EXHAUST
<br />A. Manufacturers: Acme, Ammerman, Carnes, Cook, Greenheck, Louvers and Dampers, Penn, or
<br />approved equal.
<br />B. Use low silhouette type hoods or louvered penthouse type hoods with drainable blade louvers, as
<br />shown on drawings.
<br />C. Construct hoods of aluminum (mill finish) or galvanized steel with a baked enamel finish; color to be
<br />selected by the Architect during the submittal stage.
<br />D. For hoods and louvered penthouses maintain minimum 30 inches from bottom of air intake to
<br />finished roof.
<br />E. Provide accessories as shown on drawings.
<br />Reece, Noland & McElrath, Inc. 239150-2 Orange County Board of Elections
<br />Orange Co., NC 05/04/18
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