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Southern Human Services Center Smith Sinnett /2020072 <br />HVAC and Roof Renovations Orange County,North Carolina <br />HVAC Ducts and Casings 23 31 00 - 4 <br />b.Hamlin <br />c.SMC <br />d.McGill Airflow <br />e.Or Approved Equal <br />B.Spiral Ducts: Round spiral lockseam duct with galvanized steel outer wall. <br />1.Manufacture in accordance with SMACNA (DCS). <br />2.Manufacturers: <br />a.EHG,a DMI Company <br />b.GSI,a DMI Company <br />c.Linx Industries,Inc,a DMI Company <br />d.MKT Metal Manufacturing <br />e.Or Approved Equal <br />C.Flexible Ducts: UL 181,Class 0,interlocking spiral of aluminum foil. <br />1.Insulation: Fiberglass insulation with aluminized vapor barrier film. <br />2.Pressure Rating: 8 inches WG positive or negative. <br />3.Maximum Velocity: 5000 fpm. <br />4.Temperature Range: Minus 20 degrees F to 250 degrees F. <br />5.Insulation:R6.0 <br />a.Insulation material shall not be exposed to airstream. <br />6.Manufacturers: <br />a.Lindab <br />b.Flexmaster <br />c.Clevaflex <br />d.Thermaflex <br />e.Or Approved Equal <br />2.06 LONGITUDINAL SEAM: <br />A.Rectangular Duct: <br />1.Unless otherwise indicated,use Pittsburgh lock seam construction. <br />2.Seal longitudinal seams with approved sealant or provide pre-sealed from factory with <br />encapsulated mastic. <br />3.Button punch snap lock construction (SMACNA L-2)is not allowed except for ductwork that is <br />both low pressure (2”WG or lower pressure class)and 18”and smaller duct width. <br />4.Button punch snap lock construction is not allowed for ductwork in chases and areas above <br />inaccessible ceilings. <br />5.Button punch snaplock construction is not allowed on exhaust ductwork or aluminum <br />ductwork <br />B.Round and Oval Duct <br />1.Unless otherwise indicated,longitudinal seams shall be in accordance with SMACNA HVAC <br />Duct Construction Standards with the following exceptions: <br />a.Snaplock seams are not allowed. <br />b.SMACNA seam types RL-3,6A,6B,7,and 8 shown in Figure 3-2 are not allowed, <br />except for 2"w.g.class round ducts 16"or less in diameter. <br />2.07 RECTANGULAR TRANSVERSE JOINT CONNECTORS: <br />A.Slide-on Transverse Joint Connectors: <br />1.Duct constructed using engineered slide-on connector systems must be submitted and <br />conform to manufacturer’s published duct construction standards and guidelines for joint <br />classification,sheet metal gauge,intermediate and joint reinforcement size and spacing, <br />unless otherwise specified. <br />2.Manufacturer of engineered connector system must have certified independent performance <br />testing for leakage,deflection and seismic stability. <br />3.All components of the engineered system must be clearly embossed with the manufacturer’s <br />name,model number or identifying marking. <br />DocuSign Envelope ID: 94E7997D-4F29-42F6-A9B4-0A160438D2A6