Laserfiche WebLink
DUCTWORK <br />Section 15890 <br />15-1207 <br />2. Limit expanding tapers to a maximum of 20 degrees. <br />D. Run ductwork parallel to adjacent walls unless shown otherwise on plans. <br />E. Ductwork exposed to weather to be cross -broken to shed water. <br />1. At contractor's option, ductwork can be manufactured with a sloped top, with a <br />minimum angle of 5 degrees. <br />F. Joint Sealing: <br />1. Seal all concealed ductwork within the building, all ductwork within mechanical <br />rooms, and all ductwork exposed to weather air tight. Seal all standing seams, <br />transverse joints, manufactured joints and seams with duct sealant. Duct Sealant to <br />be rated for indoor and outdoor use. Sealant to be as follows: <br />a. Ductmate Proseal <br />b. McGill Airflow Uni-Coat <br />C. Or Equal <br />2. Seal punched holes, corner cracks, and all sheet metal screws. <br />3. After testing, reseal joints found to be leaking. <br />4. At ductmate joints, in addition to ductmate gaskets, seal all bolted corners to <br />eliminate air leakage at corners. <br />5. Pressure sensitive tapes shall not be considered. <br />G. Provide sheet metal angle frame at all duct penetrations to wall, floor, roof, or ceiling. <br />1. Ducts to penetrate perpendicular to walls, ceilings and floors. <br />H. Internal Duct Liner: <br />1. Provide internal duct liner as follows: <br />a. All Transfer air ducts. <br />b. Supply and return air ductwork downstream of AC Units and ducted heat <br />pumps — minimum length to be 8'-0" unless noted or shown otherwise. <br />C. All rectangular supply and return air ductwork. <br />d. Elsewhere as indicated on the drawings. <br />e. All supply and return air ductwork exposed to weather. <br />2. Internal duct liner for ducts within building installed over conditioned spaces to be as <br />follows: <br />a. 1" thick, 1.5 -pound density (minimum) with matt facing. <br />b. Thermal Performance - C Value — 0.24 BTU / (h * FT * °F) — minimum <br />C. Thermal Performance - R Value — 4.2 (h * FT * °F) / BTU — minimum <br />11 <br />