Specifications - City of Montpelier, Vermont

Title:Montpelier District HeatingCity of Montpelier, VT15891 – Metal Ductwork & AccessoriesIssue Date:September 28, 2012Page #:10 of 192.7 DUCT ACCESS DOORSA. General: Provide where indicated, duct access doors per the following schedule(adjust as required to suit specific equipment needs):Access Door Scheduleduct size (exposed width) door size30" 18" x 18"B. Construction: Construct per the requirements of SMACNA HVAC DuctConstruction Standards, Figures 72 & 73. Provide insulated doors for insulatedductwork. Provide flush frames for uninsulated ductwork, extended frames forexternally insulated duct. Provide one side hinged, other side with latchingdevices per the SMACNA schedule.C. Manufacturers: Subject to compliance with requirements, provide duct accessdoors of one of the following:1. Air Balance Inc.2. Buckley Associates3. Duro Dyne Corp.4. Register & Grille Mfg. Co., Inc.5. Ruskin Mfg. Co.6. Ventfabrics, Inc.2.8 FLEXIBLE CONNECTIONSA. General: Provide flexible duct connections wherever ductwork connects tovibration isolated equipment. Construct flexible connections of Durolon base,Hypalon coated flameproof fabric crimped into duct flanges for attachment toduct and equipment. Make airtight joint. The fabric shall remain serviceablefrom 40°F to 250°F, and shall be resistant to mildew and ultraviolet rays.Minimum fabric weight is 24 ounces per square yard. Provide adequate jointflexibility to allow for thermal, axial, transverse, and torsional movement, andalso capable of absorbing vibration of connected equipment. The connector widthshall be 3" of 24 gauge (min) sheet metal, 3" of fabric, and 3" of 24 gauge (min)sheet metal.METAL DUCTWORK AND ACCESSORIES 15891 10