pressure drop kPa feet, temperature drop/rise degree C degree F, and
capacity W Btu/hr.
a.
Cabinet: Provide manufacturer's standard galvanized steel cabinet
finished with corrosion resistant epoxy coating or lacquer
acrylic. Provide access panels for inspection and access to
internal parts. Insulate cabinet with minimum 12 mm 1/2 inch
multi-density, fiberglass insulation with exposed edges sealed or
tucked under flanges to prevent introduction of fibers into the
airstream. Female threaded pipe condensate drain connections,
supply water connections, and return water connections shall be
copper threaded fittings mechanically fastened to the cabinet.
Water piping shall be insulated. Construct cabinet with
compartments and locate the compressor, reversing valve, and water
coil out of the airstream. Insulate the divider between the
compressor and fan sections. The control box shall be located
within the unit.
b.
Fans: Provide centrifugal type, direct drive fans with
permanently lubricated motors. Motors shall be permanent split
capacitor (PSC) type with thermal overload protection.
c.
Refrigerant-to-Air Heat Exchanger: Provide coil constructed of
rifled copper tubes with plate aluminum fins designed for
refrigerant working pressure of 3102 kPa 450 psi. The condensate
drain pan shall be epoxy coated and insulated. Provide internal
traps on vertical units. Provide drain pan with overflow
protection.
d.
Filter Section: Provide [replaceable (throwaway) [25 mmone inch] [
50 mm2 inch] thick UL listed fiberglass] [permanent washable] type
filters with [standard dust-holding capacity] [a mean efficiency
of [35] [65] percent when tested in accordance with ASHRAE 52.1].
Mount filters in filter frames and provide access panels or doors
for removal and replacement of filters.
e.
Compressor: Provide hermetically sealed type compressor,
installed on vibration isolators enclosed in an acoustically
treated enclosure. Provide high and low pressure switches, low
suction temperature cut-out, motor thermal overload protection, 5
minute anti-recycle timer, and start capacitor kit. Provide
capability to reset compressor lockout circuit at the remote
thermostat and at the disconnect. [Provide units with factory
installed sound attenuation package.]
f.
Reversing Valve: Provide solenoid activated refrigerant reversing
valves energized only during the cooling mode and designed to fail
in the heating position.
g.
Refrigerant-to-Water Heat Exchangers: [Provide
refrigerant-to-water heat exchangers of coaxial type, with inner
cupronickel water tube and outer steel refrigerant tube.] Heat
exchanger shall be tested and rated for 3102 kPa 450 psi
refrigerant working pressure. A parallel capillary tube/thermal
expansion valve assembly shall provide superheat over [one to 43
degree C30 to 110 degree F] [7 to 32 degree C45 to 90 degree F]
liquid temperature range.
[h.
Factory-Installed Domestic Hot Water Desuperheater:
Provide
SECTION 15741N
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