AAON RQ-006 - Manual (Page 49)

49
Piping systems should not exceed 10 ft/sec
fluid velocity to ensure tube wall integrity
and reduce noise.
Condensate Drain Piping
2-6 ton units are equipped with one
condensate drain pan connection, on the
right side of the unit, and are furnished with
a p-trap for field installation.
All drain connections must be used and
individually trapped to ensure a minimum
amount of condensate accumulation in the
drain pans. ABS type cement should be used
to join the drain pipe connections.
Drainage of condensate directly onto the
roof may be acceptable in certain areas, refer
to local codes. If condensate is to drain
directly onto the roof a small drip pad
should be placed below the drain to protect
the roof from possible damage.
If condensate is piped into the building
drainage system, the drain pipe should
penetrate the roof external to the unit itself.
The drain line should be pitched away from
the unit at least 1/8 inch per foot. On longer
runs an air break should be used to ensure
proper drainage.
Draw-through cooling coils will have a
negative static pressure in the drain pan area.
This will cause an un-trapped drain to back
up due to air being pulled up through the
condensate drain piping.
Condensate drain trapping and piping should
conform to all applicable governing codes.
Discharge and Suction Line Piping
There are two different locations to pipe out
of the unit, the post corner hole location and
the post back hole location. The post corner
hole location is to run pipe along the roof
and then down by the disconnect switch
(Figure 22 and Figure 24). The post back
hole location is to run the pipe along the
roof, back across the coil, and come out near
the blower access panel (Figure 23 and
Figure 25).
When drilling the holes, use a 1 ¼ inch hole
for the suction line and a 1 inch hole for the
liquid line (Figure 22 and Figure 23). For
pipe sizing, refer to appropriate guidelines in
the condenser or condensing unit installation
manual. The grommets will help seal in
between the holes in the sheet metal and the
piping. If you are piping through the back
post foam panel, attach grommet to the
inside skin of the foam part. If you are
piping through post corner hole location, use
caution around electrical wires. You will
need to turn off power to the unit.
Unit should not be operated without a
p-trap. Failure to install a p-trap may
result in overflow of condensate
water into the unit.
CAUTION