Unit Installation; Piping - Daikin Enfinity Installation And Maintenance Manual

Piping

1 . All units should be connected to supply and return
piping in a two-pipe reverse return configuration. A
reverse return system is inherently self-balancing
and requires only trim balancing where multiple
quantities of units with different flow and pressure
drop characteristics exist in the same loop. Check
for proper water balance by measuring differential
temperature reading across the water connections.
To insure proper water flow, the differential flow
should be 10°F to 14°F (5°C to 8°C) for units in
cooling mode. A direct return system may also work
acceptably, but proper water flow balancing is more
difficult to achieve and maintain.
2 . The piping can be steel or copper.
WARNING
Polyolester Oil, commonly known as POE oil is a synthetic oil
used in many refrigeration systems. POE oil, if ever in contact
with PVC/CPVC will coat the inside wall of PVC/CPVC pipe
causing environmental stress fractures. It is recommended
that PVC/CPVC piping is not used in the installation of the loop
system, as system failure and property damage could result.
Figure 12: Typical piping
Water
Return
Water
Supply
IM 1059-12 LARGE VERTICAL WSHP
Balancing Valve
with Close-off
Shutoff Valve
Flexible Hoses
3 . Supply and return run-outs usually join the unit via
short lengths of high pressure flexible hose which
are sound attenuators for both unit operating noise
and hydraulic pumping noise. One end of the hose
should have a swivel fitting to facilitate removal for
service. Hard piping can also be brought directly to
the unit. This option is not recommended since no
vibration or noise attenuation can be accomplished.
The hard piping must have unions to facilitate unit
removal. See Figure 12
4 . Some flexible hose threaded fittings are supplied
with sealant compound. If not, apply Teflon tape to
assure a tight seal.
5 . Supply and return shutoff valves are required
at each conditioner. The return valve is used for
balancing and should have a "memory stop" so that
it can always be closed off but can only be reopened
to the proper position for the flow required.
6 . No unit should be connected to the supply and return
piping until the water system has been cleaned and
flushed completely. After the cleaning and flushing has
taken place, the initial connection should have all valves
wide open in preparation for water system flushing.
7 . Condensate piping can be steel, copper or PVC.
Each unit includes a condensate connection.
Condensate Drain with
Trap and Clean-out
12
u i
nit nstallation
for typical piping setup.
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