seal joints, [stationary] [adjustable] galvanized steel louvers with
birdscreen, and bearing AMCA Certified Ratings Seal in accordance with AMCA
500-D.
2.2.2
Dampers
Provide with factory mounted [outside and return air dampers in mixing
boxes] [face and bypass dampers] [multi-zone dampers] of galvanized steel
blades, [with vinyl bulb edging] [and edge seals] in galvanized frame, in
[parallel] [opposed] blade arrangement with non-slip keyed connecting rods
and linkages. Permanently secure damper blades on a single shaft with
self-lubricating [nylon] [brass] [oil impregnated bronze] bearings.
Position damper blades across short air opening dimension. Maximum leakage
is 2 percent at 1000 Pa 4 inch water gage differential pressure when sized
for 10 m/s 2000 fpm face velocity.
2.2.3
Supply Blower (Fan) Sections
[Centrifugal fan of [backward-inclined] [forward-curved] [airfoil] blades
with [direct] [or] [V-belt] drive motor] [or] [vaneaxial fan with
[direct-drive TEAC motor] [or] [V-belt drive motor, adjustable, with belt
guards for external mounted motors. Belt guards are not required for
internally mounted motors]]. Provide [manual inlet vanes] [automatic inlet
vanes or variable speed motor as indicated]. Bearings shall be
grease-lubricated ball-bearing type, with minimum average life of 200,000
hours at design operating conditions.
2.2.4
Vibration Isolation
For the entire fan, motor, and drive assembly, provide 50 mm 2 inchnominal
deflection spring vibration isolators, internally mounted at the factory
together with fan discharge flexible connection and thrust restraint
springs. As an alternate, vibration isolation may be provided external to
air handlers. When alternate is chosen, provide 50 mm 2 inch nominal
deflection springs, pipe and duct flexible connections, thrust restraint
springs, and spring type pipe hangers on pipes directly-connected to such
air handlers.
2.2.5
Filter Sections
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NOTE: Select air filters based on ASHRAE "Handbook,
Equipment." Provide two sets of filters for
application requiring high infiltration efficiency
above 85 percent per ASHRAE 52.1. Prefilters shall
be viscous or dry throw-away type, 60 percent
minimum efficiency per ASHRAE 52.1; after-filters
shall be of dry media type, absolute, or
electrostatic precipitators. The following may be
used as a guide only; selection of filters should
suit the project requirements.
1.
General Application:
Air Handling Type
m/3 Range
Filter Type
Air Handling Type
CFM Range
Filter Type
Factory-fabricated
Up to 4,000
Viscous or
dry type
SECTION 15720N
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