Daikin DPSA Manual page 36

C. Dehumidification operation with Hot gas reheat
shall use direct air temperature feedback from the
leaving face of the evaporator coil for controlling
the compressor cooling capacity and the reheat
will be fully modulate to maintain the leaving/
supply air temperature set point. The leaving/supply
air temperature set point can be reset based on
outside, space, and return temperature or humidity.
D. Dehumidification operation with liquid sub-cool
reheat shall use direct air temperature feedback
from the leaving face of the evaporator coil for
controlling the compressor cooling capacity and
the reheat will be fully modulate to maintain the
leaving/supply air temperature set point. If the
liquid sub-cool coil does not have the capacity
to meet the leaving air temperature set point,
then the modulating hot gas reheat will trim the
remaining reheat load required. The leaving/supply
air temperature set point can be reset based on
outside, space, and return temperature or humidity.
2 . 1 1 Chilled Water Coils
A. The cooling coil section shall be installed in a draw-
through configuration, upstream of the supply air
fan. The coil section shall be complete with factory
piped cooling coil and sloped drain pan. Hinged
access doors on both sides of the section shall
provide convenient access to the cooling coil and
drain pan for inspection and cleaning.
B. All coils are fabricated of seamless 5/8" diameter
copper tubing that is mechanically expanded into
high efficiency aluminum plate fins. Coils shall
be multi-row, staggered tube design per the job
schedule. All coils shall be factory leak tested with
high-pressure air under water. All coils shall be ARI
certified.
C. Chilled water coils shall have copper headers
complete with supply, return and threaded vent
connections. Chilled water coils shall also include
threaded drain connections. Glycol shall be used to
the water circuit to protect against coil freeze-up. c
D. 2-way chilled water control valves shall be factory
installed and controlled and will be characterized Cv
ball valves.
CAT 258 • REBEL APPLIED ROOFTOP
2 . 1 2 Hot Water Heat Coils
A. A hot water heating coil shall be factory installed
in the heat section. The rooftop unit shall include a
piping vestibule. The coil connection shall terminate
in the vestibule. All coil connections shall be copper,
steel connections shall not be allowed in order to
prevent dielectrics and corrosion.
B. Coils shall be fabricated of seamless 5/8" diameter
copper tubing that is mechanically expanded into
high efficiency rippled and corrugated aluminum
plate fins. All coil vents and drains shall be factory
installed. Hot water coil shall be fully cased to allow
for easy replacement.
C. The coil shall have freeze protection and shall
be controlled by the unit DDC controller. With the
detection of a freeze condition the heating coil valve
shall be driven fully open. The unit controller shall
indicate an alarm.
D. Coil shall be factory leak tested with high pressure
air under water.
E. Provide with a factory installed and control two-way
characterized control valve with a normally open
spring close actuator
F. Provide with a factory installed and control two-way
characterized control valve with a normally open
spring close actuator and valve isolation valves
G. Provide with a factory installed and control three-
way characterized control valve with a normally
open spring close actuator
H. Provide with a factory installed and control three-
way characterized control valve with a normally
open spring close actuator and valve isolation valves
2 . 1 3 Steam Heat Coils
A. A steam heating coil shall be factory installed in
the unit heat section. Coils shall be fabricated
of seamless 5/8" diameter copper tubing that is
mechanically expanded into high efficiency HI-F
rippled and corrugated aluminum plate fins. Steam
coils shall be of the jet distributing type. A factory-
tested diffuser shall be used in order to provide air
distribution across the coil. Hinged access doors
shall provide convenient access to the coil and valve
for inspection and cleaning.
B. A factory installed two-way modulating control valve
and spring return valve actuator shall provide control
of the steam. The valve actuator shall be controlled
by the factory installed main unit control system.
C. Coils shall be factory leak tested with high pressure
air under water.
36
General Specification
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