primaries, automatic dampers, fire dampers, coils, thermostats, and other
apparatus requiring service and inspection in the duct system. Provide
access doors upstream and downstream of air flow measuring primaries and
heating and cooling coils. Doors shall be minimum 375 x 450 mm 15 x 18
inches, unless otherwise shown. Where duct size will not accommodate this
size door, the doors shall be made as large as practicable. Equip doors
600 x 600 mm 24 x 24 inches or larger with fasteners operable from inside
and outside the duct. Use insulated type doors in insulated ducts.
2.6.2.2
Fire Dampers
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NOTE: Indicate the location of each fire damper and
details of the damper installations according to
NFPA 90A. Three-hour rated fire dampers must be
specifically identified on the drawings. Pressure
relief damper upstream of the fire damper will be
used for Army and Air Force projects only.
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Use 1.5 hour rated fire dampers unless otherwise indicated. Fire dampers
shall conform to the requirements of NFPA 90A and UL 555. The Contractor
shall perform the fire damper test as outlined in NFPA 90A. Provide a
pressure relief damper upstream of the fire damper. If the ductwork
connected to the fire damper is to be insulated then this pressure relief
damper shall be factory insulated. Fire dampers shall be automatic
operating type and shall have a dynamic rating suitable for the maximum air
velocity and pressure differential to which it will be subjected. Fire
dampers shall be approved for the specific application, and shall be
installed according to their listing. Fire dampers shall be equipped with
a steel sleeve or adequately sized frame installed in such a manner that
disruption of the attached ductwork, if any, will not impair the operation
of the damper. Equip sleeves or frames with perimeter mounting angles
attached on both sides of the wall or floor opening. Construct ductwork in
fire-rated floor-ceiling or roof-ceiling assembly systems with air ducts
that pierce the ceiling of the assemblies in conformance with UL Fire
Resist Dir. Fire dampers shall be [curtain type with damper blades] [in
the air stream] [out of the air stream] [or] [single blade type] [or]
[multi-blade type]. Dampers shall not reduce the duct or the air transfer
opening cross-sectional area. Install dampers so that the centerline of
the damper depth or thickness is located in the centerline of the wall,
partition or floor slab depth or thickness. Unless otherwise indicated,
comply with the installation details given in SMACNA Install Fire Damp HVAC
and in manufacturer's instructions for fire dampers. Perform acceptance
testing of fire dampers per paragraph Fire Damper Acceptance Test and NFPA
90A.
2.6.2.3
Manual Balancing Dampers
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NOTE: Show all volume dampers on the drawings. Do
rely upon diffuser and register volume dampers for
balancing.
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Furnish manual balancing dampers with accessible operating mechanisms. Use
chromium plated operators (with all exposed edges rounded) in finished
portions of the building. Manual volume control dampers shall be operated
by locking-type quadrant operators. Dampers shall be 2 gauges heavier than
SECTION 15895
Page 18
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