STEAM EXPANSION PHASE 1PROJECT NO.: 9507400

UNIVERSITY OF CALIFORNIA, DAVIS

DAVIS, CALIFORNIA

SECTION 15890-DUCTWORK

PART 1 - GENERAL

1.1SCOPE OF WORK

  1. Provide labor, materials, and services necessary for a complete installation of the following:
  2. Low pressure ducts.
  3. Casings, plenums and equipment housing.
  4. Duct cleaning.
  1. quality assurance
  2. Refer to Section 15010 General Provisions Mechanical.
  3. Construct ductwork to NFPA 90A andNFPA 90B standards.
  4. Duct system shall be constructed, installed, sealed and insulated as provided in California Building Code 2001.
  5. SUBMITTALS
  6. Submit product data, drawings, and schedules for the following items per the provisions of Section 01334 Shop Drawings, Product Data and Samples.
  7. Product data: Manufacturer’s data on all factory made items specified herein.
  8. Drawings: Coordinated layout duct drawings that differ from ductwork shown on Contract Drawings. Mechanical equipment room plans and sections showing all equipment, curbs, and accessories at minimum 3/8 inch. scale, double line, showing sizes, transverse joints, transitions, elevations, clearances, accessories, and sections where required. Show details of casing and plenum construction.
  9. Schedules: Ductwork construction, including gauge and bracing schedules.
  10. DEFINITIONS
  11. Duct Sizes: Shown on the plans as clear inside dimensions. For lined ducts, maintain sizes inside lining.
  12. Seam: locks or weld applied longitudinally to close section of duct, e.g. longitudinal seam, spiral seam.
  13. Joint: abutting connection between duct sections for continuity of air passage, e.g. cross joint, transverse joint, coupling.
  14. Reinforcement: hardware applied to strengthen duct, e.g. girth angles, tie rods, fasteners (not connectors), etc.
  15. Stiffening: folding, bending, beading, crossbreaking or corrugating of sheets to achieve strength through shape, e.g. pocket lock secures joint and is transverse stiffener, with girth angle or fasteners applied (not connectors), joint or stiffener is reinforced.
  16. DUCT CLASSIFICATION
  17. Velocity:
  18. Low: to 2000 feet per minute.
  19. Medium or high: above 2000 feet per minute.
  20. Pressure:
  21. Based on following:
  22. Single duct systems: static pressure at respective point in ductwork during normal operation.
  23. Variable volume systems: from fan discharge to variable volume units, based on static pressure at beginning of fan discharge duct.
  24. Pressure classification: except as noted:
  25. Low: to 2 inch w.g.
  26. System Schedule:
  27. Low:
  28. Supply: air handling unit to outlets.
  29. Exhaust.
  30. Transfer.
  31. DELIVERY, STORAGE, AND HANDLING
  32. Refer to Section 01610 Basic Product Requirements for delivery, storage and handling requirements.

PART 2 - PRODUCTS

2.1MANUFACTURERS

  1. Flat oval and round duct and fittings:
  2. United Sheet Metal Division.
  3. United McGill Corporation.
  4. US Air Duct Corporation.
  5. O equal
  6. Flexible ducts (low pressure):
  7. General Environment Corporation.
  8. H.K. Porter Co.
  9. Wiremold Co.
  10. Clevaflex Div.
  11. Clevepak Corp.
  12. Flexaust Co.
  13. Or equal
  14. Duct Sealants:
  15. Benjamin Foster Corp.
  16. Minnesota Mining Manufacturing Co. (3M)
  17. United Sheet Metal Division.
  18. United McGill Corporation.
  19. Miracle Adhesives, Corp.
  20. HardCast, Inc.
  21. Or equal
  22. Spring Fasteners
  23. Dzus.
  24. Simmons "Quick-Lock".
  25. Or equal
  26. Mechanical Duct Coupling Systems:
  27. Ductmate Industries, Inc., or equal.
  1. MATERIALS
  2. Metal sheets shall be as follows:
  3. Galvanized steel shall be in accordance with ASTM 5261; black or galvanized as herein after specified.
  4. DUCTWORK
  5. Ductwork shall be galvanized steel, except as noted, in accordance with SMACNA HVAC Duct Construction Standard, except as noted. Provide gauges, construction and reinforcement as follows:
  6. Pressure class 2 inch. w.g.
  7. Sheet metal gauge and reinforcement shall be in accordance with SMACNA Table 1-5 and 1-10 through 1-13 and based on a minimum of 2 inch. w.g. duct pressure class regardless of possible lower pressures. Round ductwork shall be spiral or longitudinal seam. Cross breaking shall be as required for rigid support.
  8. Watertight construction where noted with edges bent 1/2 in. for watertight seal. Longitudinal seam sealant shall be 3M Brand No. 800; Alcoa, Aluminastic Type C, or
    equal; Stiffeners shall be plug or spot welded. Transverse joints shall be bolted companion angles with 1/4 in. cadmium plated bolts with 6 in. minimum on centers and gasket.
  9. Airtight construction where noted with longitudinal seams soldered. Stiffeners shall be plug or spot welded. Transverse joints shall be bolted companion angle with 1/4 inch cadmium plated bolts with 6 in. minimum or centers and gasket. Exposed, uninsulated ductwork shall be flush flat seam. Provide airtight concrete, masonry and other construction materials for plenums and shafts only where noted.
  10. Outside air, exhaust and relief duct shall be as follows:
  11. Aluminum.
  12. Within 10 feet. of louvers.
  13. Louvers to casings.
  14. Watertight.
  15. FLEXIBLE DUCTS
  16. General:
  17. Use only where specified or indicated.
  18. UL 181, Class I Air Duct.
  19. Labeled for compliance with UMC.
  20. Low Pressure:
  21. Insulated Flexible Duct:
  22. Minimum working pressure 2 inch w.g. positive and 1.5 inch w.g. negative.
  23. Nominal 1 in. insulation with vapor barrier.
  24. Maximum thermal conductivity 0.27 BTUH/sq. ft. degrees F/in at 75 degrees F.
  25. Use at following locations:
  26. Connection to ceiling supply air outlets.
  27. As indicated.
  28. Wiremold Type WG or equal.
  29. Flexible duct shall be constructed in accordance with NFPA 90A; U.L. 181 Class 1 (maximum flame spread: 25, maximum smoke developed: 50). Performance and installation shall be in accordance with SMACNA HVAC Duct Construction Standards, Metal and Flexible. Maximum length shall be 18 inches with no intermediate seams.
  30. Flexible duct for class 2 inch w.g. shall be polyester reinforced aluminum foil over corrosion resistant wire helix, Wiremold WC or equal.
  31. Flexible duct for pressure class 2 inch w.g. shall be high temperature copolymer impregnated glass fabric, locked to cold rolled flat steel spiral, Wiremold 57 or equal.
  32. Flexible duct connections to oval collars shall be with preshaped oval ends. Secure flexible duct with clamps and sealer or screws, sealer and tape for metal flexible ducting. Attach to rectangular supply air duct with low entrance loss, bellmouth type connector on air inlet end. Flexible shall not lay across lighting fixtures or other surfaces; provide hanger supports as required.
  33. CASINGS, HOUSINGS AND PLENUMS
  34. Pressure class 2 inch w.g. shall be galvanized steel unless otherwise noted:
  35. Single wall, minimum No. 16 USSG.
  36. Provide for outdoor air intake plenums, exhaust plenums open to weather, and blow through units from fan discharge to leaving side of coil, as follows:
  37. Aluminum; single wall, watertight.
  38. AUTOMATIC DAMPERS
  39. Install automatic dampers supplied by Contractor. Notch end of rod and label duct or casing to indicate open and closed position.
  40. FLEXIBLE CONNECTIONS
  41. Flexible connections for ductwork shall be in accordance with SMACNA HVAC Duct Construction Standards, Metal and Flexible, except as noted. Flexible connections with metal collars shall be installed with 2 in. slack in fabric and minimum movement of 1 in. Provide flexible at connections to fans, building expansion joints, at connection between copper and stainless steel ductwork and at penetrations of mechanical equipment room walls.
  42. Provide neoprene coated glass fabric, 30 oz. per sq. yd. with sewn and cemented seams, Vent Fabrics, Inc. or equal. For kitchen exhaust, provide wire imbedded glass cloth with sewn seams as manufactured by Vent Fabrics, or equal.
  43. TURNING VANES
  44. For galvanized steel ductwork, provide galvanized steel, except as noted. For other ductwork, provide same material as ductwork. Turning vanes shall be single thickness with flat trailing age, in accordance with SMACNA HVAC Duct Construction Standards, except as noted.
  45. Install at square duct elbows and as noted on Drawings. Maximum unsupported vane length shall not exceed 48 inch. Provide separate equal size sections for greater lengths. Refer to turning vane detail. ASHRAE and SMACNA show better performance for single thickness.
  46. Angles, tie rods and shapes for reinforcing joints shall be in accordance with SMACNA HVAC Duct Construction Standards, except for the following:
  47. Reinforcing angle spacing shall not exceed 24 inch. spacing and applied to four sides for following distances from fan inlet and outlet for each system.
  48. Ten ft. for fans with wheel diameter to 27 inch.
  49. Twenty ft. for fans with wheel diameters exceeding 27 inch.
  50. Galvanized and aluminum sheets: Provide galvanized steel.
  51. Stainless steel sheets: Provide stainless steel.
  52. Copper sheets: Provide stainless steel, brass or bronze.
  53. Screws and rivets: Provide the same material as sheet, except as noted. On aluminum sheets, provide cadmium plated or stainless steel. Zinc or cadmium plated will be permitted on galvanized sheets. Minimum screw size shall be No. 10; maximums pacing shall be 10 in. Minimum rivet size shall be 4 lb.; maximum spacing shall be 6 inch.
  54. Duct sealants:
  55. Provide sealing compound for brush applications, 3M Brand No. 800 or equal and other applications, 3M Brand No. 900 or equal. Provide tape, 3M No. 474 or equal. For gaskets, provide continuous, reinforced, inert self-conforming type, 1/8 inch. thick and width to match angle connection, 3M Weatherban 1202-T ribbon sealer or equal.

PART 3 - EXECUTION

3.1DUCTWORK INSTALLATION

  1. General:
  2. Construct with gauges, joints, bracing, reinforcing, and other details per latest UMC (or CMC), ASHRAE, SMACNA, (or NFPA) unless specified otherwise.
  3. Comply with most stringent.
  4. Provide ducts with NFPA 90A gauges when traversing smoke zones.
  5. Construct of galvanized sheet metal, except where otherwise indicated.
  6. Diagonally crossbreak all panels on metal rectangular ducts over 18 inches in either direction.
  7. Beading for reinforcing not acceptable.
  8. Crossbreak outward in ducts having positive internal pressure.
  9. Crossbreak inward in ducts having negative internal pressure.
  10. Duct dimensions indicated are net, inside, clear, dimensions.
  11. For internally lined ducts, add lining thickness to determine metal duct dimensions.
  12. Classification: Classify and construct ducts per latest regulation as follows:

LP / LP / LP
SMACNA: / 1/2 / 1 / 2
SP inch:
  1. Alter duct sizes on basis of equal friction where required to facilitate installation.
  2. Avoid penetrations of ducts.
  3. Provide airtight rubber grommets at unavoidable penetrations of hanger rods.
  4. At exposed duct penetrations of walls, floors and ceilings, provide sheet metal angle type escutcheons.
  5. At supply diffusers, grilles or registers extend branch duct 1 foot beyond air outlet, except as detailed otherwise.
  6. Install exposed ducts to maintain not less than 7 ft. head clearance, unless indicated otherwise.
  7. Tapers:
  8. Pitch sides of duct in "diverging" or "converging" airflow maximum of 1 to 4 taper.
  9. Duct openings:
  10. Provide openings where required to accommodate thermometers smoke detectors, controllers, etc.

1)Insert through airtight rubber grommets.

  1. Provide pitot tube openings where required for testing of systems:

1)Complete with metal cap with spring device or screw to ensure against air leakage.

2)For Pitot tube tests install Ventlok No. 699, 699-2, or equal instrument

test holes.

  1. Where openings are provided in insulated ductwork, install insulation material inside metal ring.
  1. Flexible Duct Connections:
  2. Coated glass fabric.

1)For indoor or outdoor use as specified hereinbefore.

  1. Install at:

1)Connections to fans and air handling units.

2)In high velocity ducts at penetrations of mechanical equipment room walls.

a)As specified for fans.

3)Additional as indicated on Drawings.

  1. Volume dampers.
  2. See Section 15910 Ductwork Accesories.
  3. Install damper in every branch.
  1. Elbows and Transitions:
  2. Construct radius elbows with inside radius not less than duct width.
  3. Use square turns in rectangular ductwork, unless indicated otherwise, at following locations:
  4. Exposed elbows.
  5. Immediately upstream from supply air outlets.
  6. Where required to facilitate installation.
  7. Provide turning vanes in miter elbows in round and rectangular ducts.
  8. Where indicated, provide elbow with splitter vanes of special size and shape, per SMACNA Duct Standards, Section 5.
  9. In high and medium pressure ductwork spot weld turning vane to duct.
  10. Two-way splits:
  11. Supply, return and exhaust.
  12. Two elbows:

1)Proportionally sized per SMACNA Duct Standards.

2)Radius or square.

  1. Single fitting acceptable.

1)With turning vanes.

2)Duct openings sized as above.

  1. Rectangular Duct Joints:
  2. Standing seams, except where flush drive slip seam called for.
  3. Use flush, drive-slip, for:
  4. Exposed ducts:

1)Except in garages, mechanical rooms.

  1. Where required for clearance.
  1. "Ductmate" system joints, may be used in lieu of standing seams.
  2. In ducts no wider than 60 in.
  1. Joint Sealing:
  2. Seal transverse and longitudinal joints of sheet metal ducts by one of following methods:
  3. Six ounce canvas strip, six in. wide.

1)Adhere with lagging adhesive.

  1. Hardcast PS-S tape or equal.
  2. United Hi-Velocity sealer or equal.
  3. Applications as recommended by manufacturer.
  1. Seal punched holes and corner cracks.
  2. After installation and testing reseal joints found to be leaking.
  1. DUCT HANGERS AND SUPPORTS
  2. General:
  3. Support horizontal ducts with hangers of size and spacing as indicated in pertinent SMACNA Duct Construction Standards.
  4. Attachment to structure: As specified in Section 15145 Pipe Hangers, Supports and Guides.
  5. Vibration isolation for ducts: As specified in Section 15242 Vibration Isolation.
  6. Horizontal Duct Supports:
  7. Install hangers at each change in direction of duct.
  8. Strap hangers:
  9. Extend strap down both sides of ducts.
  10. Turn under bottom 1 inch minimum.
  11. Metal screw hangers to:

1)Bottom of duct.

2)Upper and lower sides of ducts.

3)Not more than 12 inches on center.

  1. Angle hangers:
  2. Provide angle hangers formed by extended vertical bracing angles.
  3. Or by rods connecting to bottom angles if size or bracing angles conform to hanger schedule.
  4. Vertical duct supports:
  5. Support vertical ducts at every floor:

1)Use angles or channels riveted to ducts.

2)Set angles or channels on floor slab or structural steel members placed in opening, unless otherwise noted.

END OF SECTIOn 15890

April 13th, 2007DUCTWORK

Revision: 015890-1