Specifications

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Piping
1. All units should be connected to supply and return
pipinginatwo-pipereversereturnconguration.
A reverse return system is inherently self-balancing
and requires only trim balancing where multiple
quantities
ofunitswithdifferentowandpressure
drop characteristics exist in the same loop. Check
for proper water balance by measuring differential
temperature reading across the water connections.
T
oinsureproperwaterow,thedifferentialow
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owbalancingismore
difculttoachieveandmaintain.
2. The piping can be steel, copper or PVC.
3. Supply and return runouts usually join the unit via
shortlengthsofhighpressureexiblehosewhich
are sound attenuators for both unit operating noise
and hydraulic pumping noise. One end of the hose
should
haveaswiveltting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 14 for typical piping setup.
4.
Someexiblehosethreadedttingsaresupplied
withsealantcompound.Ifnot,applyTeon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
owrequired.
6. No unit should be connected to the supply and return
piping until the water system has been cleaned and
ushed
completely.Afterthecleaningandushing
has taken place, the initial connection should have
all valves wide open in preparation for water system
ushing.
7.
Condensate piping can be steel, copper or PVC.
Each unit includes a condensate connection.
8.
The condensate disposal piping must have a trap.
The piping must be pitched away from the unit not
less
than1⁄4"perfoot(21mmpermeter).Generally,
the condensate trap is made of copper and soldered
on the unit. A piece of vinyl hose from the trap to
the drain line is used for simple removal. A complete
copper or PVC condensate system can also be used.
Union
ttingsinthecopperlinesshouldbeapplied
to facilitate removal. Factory supplied condensate
hose
assemblieshavepipethreadttingstofacilitate
connectionofaexiblevinylorsteelbraidedhose.
9. Do not locate any point in the drain system above
the drain connection of any unit.
10.
Automaticowcontrolleddevicesmustnotbe
installedpriortosystemcleaningandushing.
11. A high point of the piping system must be vented.
12.Checklocalcodefortheneedfordielectricttings.
Figure 14: Typical Piping
Do not overtorque fittings. The maximum torque without
damage to fittings is 30 foot pounds. If a torque wrench is
not available, use as a rule of thumb, finger-tight plus one
quarter
turn. Use two wrenches to tighten the union, one
to hold the line and one for simultaneous tightening of the
nut
.
CAUTION
Balancing Valve
with Close-off
Shutoff Valve
Flexible Hoses
Condensate Drain with
Trap and Clean-out
Water Return
Water Supply