SPECIFICATIONS

Fort Nelson NRRM AIR SECTION 15880
Airport Terminal Building DISTRIBUTION Page: 1
Washroom Renovations
15890 DUCTWORK
1. Duct construction shall be in accordance with recommendations set forth in the current edition
of Sheet Metal and Air Conditioning National Association Duct Construction Standards.
2. Unless noted otherwise, ductwork shall be fabricated from G90 commercial quality galvanized
steel. All materials used shall be new and in good condition. Where ductwork is exposed,
provide materials which are free from visual imperfections including pitting, dents, and other
imperfections, including those which would impair painting.
3. The drawings do not attempt to show all offsets. The contractor shall make necessary offsets at
no additional cost to the Owner. Offset angles shall be as small as possible.
4. Curved elbows are preferred and shall have a centre-line radius equal to 1 1/2 times the duct
width. Air turning vanes shall be installed in all abrupt or square elbows. They shall be
standard manufactured products, quiet and free from vibration when system is operating.
5. Volume dampers shall be installed in each branch duct to allow proper balancing. Dampers
shall be complete with quadrant and locking device equal to Duro Dyne K-4, K-5 for rectangular
ducts, K-2 or KR-3 dial for round ducts. Dampers shall be Model MBD-57 or MB-RD-84 as
manufactured by Price Ltd. or approved equal. In rectangular ducts, dampers 305mm [12"] in
height or less shall be single blade type. Larger rectangular ducts shall have opposed blade type.
Round ducts 610 mm [24"] dia. or less, shall have single blade dampers. Larger ducts shall
have opposed blade dampers.
6. ULC labelled fire dampers shall be provided where indicated. Fusible links shall have a melting
point of 71°C (160°F) or approximately 30°C (54°F) higher than maximum anticipated
temperature, whichever is higher. Unless noted otherwise on drawings, dampers shall be as
manufactured by Controlled Air Manufacturing Ltd., dynamic type, low resistance type B, or
approved equal. Provide access doors for fusible link inspection or replacement. Static type fire
damper is not acceptable.
7. Where ducts pierce floors, walls, or ceilings that are fire rated assemblies or fire separations,
they shall be tightly fitted and equipped with fire dampers as noted in .06. The installation shall
conform to Part 3, Sub-section 3.1.8 of the 2006 B.C. Building Code.
8. All ductwork shall be supported and restrained, as outlined in SEISMIC RESTRAINT Clause
15245, by solid straps, at not more than 3 m (10 ft.) centres, of adequate strength extending
down side of duct and turned under the bottom. On each strap provide two sheet metal screws
on side and one in bottom. Where SMACNA standards are more stringent, they shall apply.
9. Provide Duro Dyne DURALON flexible connections where indicated on drawings and for duct
connections to equipment which is not internally isolated.
February 2012 JM BEAN & CO. LTD 1130.10