COMFORT-AIRE GUH95C, Installation Instructions Manual

Page: 34 / 58

507716-01 Page 34 of 58 Issue 1717
Condensate Piping
This unit is designed for either right or left side exit of
condensate piping in upflow applications. In horizontal
applications, the condensate trap must extend below the
unit. An 8” service clearance is required for the condensate
trap. Refer to Figure 52 for condensate trap locations.
Figure 59 shows trap assembly using 1/2” PVC or 3/4”
PVC.
Figure 52.
NOTE: If necessary the condensate trap may be installed
up to 5’ away from the furnace. Use PVC pipe to connect
trap to furnace condensate outlet. Piping from furnace
must slope down a minimum of 1/4” per ft. toward trap.
1. Determine which side condensate piping will exit the
unit, location of trap, field-provided fittings and length
of PVC pipe required to reach available drain.
2. Use a large flat head screw driver or a 1/2” drive
socket extension and remove plug (Figure 52) from
the cold end header box at the appropriate location
on the side of the unit. Install provided 3/4 NPT street
elbow fitting into cold end header box. Use Teflon tape
or appropriate pipe dope.
3. Install the cap over the clean out opening at the base
of the trap. Secure with clamp. See Figure 54.
4. Install drain trap using appropriate PVC fittings, glue
all joints. Glue the provided drain trap as shown in
Figure 59. Route the condensate line to an open drain.
Condensate line must maintain a 1/4” downward slope
from the furnace to the drain.
5. Figure 55 and Figure 56 show the furnace and
evaporator coil using a separate drain. If necessary
the condensate line from the furnace and evaporator
coil can drain together. See Figure 57 and Figure 58.
Upflow furnace (Figure 53) - In upflow furnace
applications the field provided vent must be a minimum
1” to a maximum 2” length above the condensate drain
outlet connection. Any length above 2” may result in a
flooded heat exchanger if the combined primary drain
line were to become restricted.
Horizontal furnace (Figure 55) - In horizontal furnace
applications the field provided vent must be minimum
4” to a maximum 5” length above the condensate drain
outlet connection. Any length above 5” may result in a
flooded heat exchanger if the combined primary drain
line were to become restricted.
NOTE: In horizontal applications it is recommended to
install a secondary drain pan underneath the unit and
trap assembly.
NOTE: Vinyl tubing may be used for condensate drain.
Tubing must be 1-1/4” o.d. X 1” i.d. and should be
attached to the drain on the trap using a hose clamp.
Do not use copper tubing or existing copper condensate
lines for drain line.
CAUTION
6. If unit will be started immediately upon completion of
installation, prime trap per procedure outlined in Unit
Start-Up section.
Condensate line must slope downward away from the
trap to drain. If drain level is above condensate trap,
condensate pump must be used. Condensate drain line
should be routed within the conditioned space to avoid
freezing of condensate and blockage of drain line. If
this is not possible, a heat cable kit may be used on the
condensate trap and line. Heating cable kit is available in
various lengths; 6 ft. (1.8 m) - kit no. 26K68; 24 ft. (7.3 m) -
kit no. 26K69; and 50 ft. (15.2 m) - kit no. 26K70.
A separate drain line must be run to the drain from the
condensate trap to ensure proper drainage and pressure
switch operation. DO NOT connect the condensate trap
drain into the drain line from the evaporator coil.
CAUTION