AAON RL-240 - Manual (Page 36)

36
Figure 14 - Gas Heater Rain Hood Screws
Condensate Drain Piping
Unit is equipped with 2 or more condensate
drain pan connections. A drain line with p-
trap must be installed on every drain
connection, with the p-trap not to exceed 6”
from the drain connection. The lines should
be the same pipe size or larger than the drain
connection and pitched away from the unit
at least 1/8 inch per foot. An air break
should be used with long runs of condensate
lines.
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.
Note: The drain pan connections are 1.5”
MPT fitting.
Condensate drain trapping and piping should
conform to all applicable governing codes.
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 drip pad should be
placed below the drain to protect the roof
from possible damage.
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. Blow-through coils
will have a positive static pressure in the
drain pan. The condensate piping on these
drain pans must be trapped to prevent
pressure loss through the drain.
When locating gas fired units, it is
recommended the unit be installed so
that the flue discharge vents are
located at least 120 inches away
from any opening through which
combustion products could enter the
building.
WARNING
All exterior heater rain hoods must be
in place before the gas fired heater is
initially
started. Improper and
dangerous operating conditions will
otherwise result.
WARNING
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