Daikin Skyline OAH003GDAC Installation And Maintenance Manual page 22

Valves
• Do not use modulating steam valves on high pressure
systems.
• Properly size modulating valves. Do not undersize.
• Avoid freezing conditions (entering air temperatures
below 35°F).
• Daikin strongly recommends 5JA, 8JA, 5RA and 8RA coils.
• Supply 5 psi steam to coils at all times.
• Do not use modulating valves. Provide control by face
and bypass dampers.
• Consider using two or three coils in series with two
position steam control valves on the coil or coils that
handle 35°F or colder air. Use a modulating valve on the
downstream coil to provide the desired degree of control.
• Thoroughly mix fresh air and return air before it enters the
coil. Also, to obtain true air mixture temperatures, properly
locate temperature control elements.
• As additional protection against freeze-up, install the
trap sufficiently below the coil to provide an adequate
hydrostatic head to remove condensate during an
interruption in the steam pressure. Estimate three feet for
each 1 psi of trap differential required.
• On startup, admit steam to coil ten minutes before
admitting outdoor air.
• Close fresh air dampers if steam supply pressure falls
below the minimum specified.
IM 777-18 • SKYLINE OUTDOOR AIR HANDLER
Pipe Chases
Follow the these guidelines when routing piping through the
bottom of a unit.
• Cut a hole as small as possible – while still allowing
piping to run through - at the desired location(s).
— The base of a Skyline unit has a secondary drip
shield installed below every panel that drains potential
moisture to the outside frame trough. It is critical that
any cut is adequately sealed to prevent any moisture
getting through the penetration.
• The hole(s) must penetrate both the floor panel and the
secondary drip shield. Hole(s) must be located fully within
panels or sheet metal opening covers. Do not run pipes
through 4" wide intermediate panels or on the very edge
of the panel.
• Seal the holes through the floor panel and secondary
drip shield to divert any moisture away from the opening
and prevent moisture leakage through the holes.
Recommended sealing options include flashing material,
caulk, spray foam, cork tape, or other similar sealing
material.
• The installer is responsible for ensuring the penetrations
are sufficiently sealed.
NOTE: Do not support piping off of the unit or secondary drip
shield.
Figure 45: Base and Drip Shield
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