friction loss and indicate fan static pressure on
drawings for the designed ductwork configuration.
Indicate the location of each duct smoke detector in
the HVAC system and include the detectors on the
schematic and associated ladder diagram. Provide
duct smoke detectors according to NFPA 90A. Duct
detectors are intended to shut associated air
distribution fans and smoke dampers, if provided.
Duct smoke detectors are not for use inside ducts
where ambient temperatures exceeds 38 degrees C (100
degrees F).
When the building is equipped with a fire alarm
system, connect the duct smoke detectors to the fire
alarm control panel (FACP) for alarm initiation.
Show wiring to the FACP for either new or existing
fire alarm systems.
**************************************************************************
Fans shall be tested and rated according to AMCA 210. Calculate system
effect on air moving devices in accordance with AMCA 201 where installed
ductwork differs from that indicated on drawings. Install air moving
devices to minimize fan system effect. Where system effect is unavoidable,
determine the most effective way to accomodate the inefficiencies caused by
system effect on the installed air moving device. The sound power level of
the fans shall not exceed 85 dBA when tested per AMCA 300 and rated per
AMCA 301. All fans shall have an AMCA seal. Connect fans to the motors
either directly or indirectly with V-belt drive. Use V-belt drives
designed for not less than [150] [140] [120] percent of the connected
driving capacity. Motor sheaves shall be variable pitch for 11 kW 15 hp
and below and fixed pitch as defined by ARI Guideline D. Select variable
pitch sheaves to drive the fan at a speed which will produce the specified
capacity when set at the approximate midpoint of the sheave adjustment.
When fixed pitch sheaves are furnished, provide a replaceable sheave when
needed to achieve system air balance. Provide motors for V-belt drives
with adjustable rails or bases. Provide removable metal guards for all
exposed V-belt drives, and provide speed-test openings at the center of all
rotating shafts. Provide fans with personnel screens or guards on both
suction and supply ends, except that the screens need not be provided,
unless otherwise indicated, where ducts are connected to the fan. Provide
fan and motor assemblies with vibration-isolation supports or mountings as
indicated. Use vibration-isolation units that are standard products with
published loading ratings. Select each fan to produce the capacity
required at the fan static pressure indicated. Sound power level shall be
as indicated. Obtain the sound power level values according to AMCA 300.
Standard AMCA arrangement, rotation, and discharge shall be as indicated.
Power ventilators shall conform to UL 705 and shall have a UL label.
2.7.1.1
Centrifugal Fans
Centrifugal fans shall be fully enclosed, single-width single-inlet, or
double-width double-inlet, AMCA Pressure Class I, II, or III as required or
indicated for the design system pressure. Impeller wheels shall be rigidly
constructed, accurately balanced both statically and dynamically. [Fan
blades may be forward curved or backward-inclined airfoil design in wheel
sizes up to 750 mm 30 inches. Fan blades for wheels over 750 mm 30 inches
in diameter shall be backward-inclined airfoil design]. [Booster fans for
exhaust dryer systems shall be the open-wheel radial type. These fans
SECTION 15895
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