Allied Air A97USMV Installation Instructions Manual page 24

DIRECT VENT APPLICATION
USING EXISTING CHIMNEY
NOTE: Do not discharge exhaust gases directly into any chimney or
vent stack. If vertical discharge through an existing unused chimney
or stack is required, insert piping inside chimney until the pipe open
end is above top of chimney and terminates as illustrated. In any
exterior portion of chimney, the exhaust vent must be insulated.
Figure 30
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 34 for condensate trap locations.
NOTE: If necessary the condensate trap may be installed
up to 5 ft. away using PVC pipe from the furnace. Piping
from furnace must slope down a minimum of 1/4" per ft.
toward trap.
CONDENSATE TRAP AND PLUG LOCATIONS
(Unit shown in upflow position)
NOTE: In upflow applications where side return air filter is installed on
same side as the condensate trap, filter rack MUST be installed beyond
condensate trap or trap must be relocated to avoid interference.
Figure 31
Page 24 of 74
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 1/2" rachet drive or flat blade screw driver and
remove plug (Figure 31) from the cold end header box
at the appropriate location on the side of the unit. Install
field-provided 3/4 NPT male 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 38.
4. Install drain trap using appropriate PVC fittings, glue
all joints. Glue the provided drain trap as shown in
Figure 38. Route the condensate line to an open drain.
Condensate line must maintain a 1/4" downward
slope from the furnace to the drain.
5. Figures 33 and 34 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 Figures 35, 36 and 37.
Upflow furnace (Figure 32) - In upflow furnace
applications the field provided vent must be 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 33 or 37) In horizontal furnace
applications the field provided vent must be a 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.
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.
Do not use copper tubing or existing copper condensate
lines for drain line.
Issue 1622
CAUTION
507028-03