steel] [stainless steel], pitched to the drain connection. Construct drain
pans water tight, treated to prevent corrosion, and designed for positive
condensate drainage. When 2 or more cooling coils are used, with one
stacked above the other, condensate from the upper coils shall not flow
across the face of lower coils. Provide intermediate drain pans or
condensate collection channels and downspouts, as required to carry
condensate to the unit drain pan out of the air stream and without moisture
carryover. Construct drain pan so that the pan may be visually inspected
easily including underneath the coil without removal of the coil and so
that the pan may be physically cleaned completely and easily underneath the
coil without removal of the coil. Casing insulation shall conform to NFPA
90A Single-wall casing sections handling conditioned air shall be
insulated with not less than 25 mm 1 inch thick, 24 kg/cubic meter 1-1/2
pound density coated fibrous glass material having a thermal conductivity
not greater than 0.033 W/m-K 0.23 Btu/hr-sf-F. Double-wall casing sections
handling conditioned air shall be insulated with not less than 50 mm 2
inches of the same insulation specified for single-wall casings.
Foil-faced insulation shall not be an acceptable substitute for use with
double wall casing. Double wall insulation must be completely sealed by
inner and outer panels. Factory applied fibrous glass insulation shall
conform to ASTM C 1071, except that the minimum thickness and density
requirements do not apply, and shall meet the requirements of NFPA 90A.
Air handling unit casing insulation shall be uniform over the entire
casing. Foil-faced insulation shall not be an acceptable substitute for
use on double-wall access doors and inspections doors [and casing
sections]. Duct liner material, coating, and adhesive shall conform to
fire-hazard requirements specified in Section 15080 THERMAL INSULATION FOR
MECHANICAL SYSTEMS. Protect exposed insulation edges and joints where
insulation panels are butted with a metal nosing strip or shall be coated
to conform to meet erosion resistance requirements of ASTM C 1071. Provide
a latched and hinged inspection door, in the fan and coil sections.
Provide additional inspection doors, access doors and access sections
[_____] [where indicated].
2.8.2.2
Heating and Cooling Coils
Coils shall be provided as specified in paragraph AIR SYSTEMS EQUIPMENT.
2.8.2.3
Air filters shall be as specified in paragraph AIR SYSTEMS EQUIPMENT for
types and thickness indicated.
2.8.2.4
Fans
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NOTE: Coordinate with paragraph Sound Attenuation
Equipment.
Refer to UFC 3-450-02, Design: Noise and Vibration
Control, for vibration criteria. Detail vibration
isolation required and include it in the appropriate
schedule on the drawings.
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Fans shall be double-inlet, centrifugal type with each fan in a separate
scroll. Fans and shafts shall be dynamically balanced prior to
installation into air handling unit, then the entire fan assembly shall be
statically and dynamically balanced at the factory after it has been
SECTION 15895
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