Lennox SLP98UHV Installation Instructions Manual page 23

SLP98 DIRECT VENT APPLICATION
USING EXISTING CHIMNEY
8" - 12"
(203mm - 305mm)
Minimum 12" (305MM)
INTAKE PIPE
INSULATION (optional)
above chimney top
plate or average snow
accumulation
INSULATE
TO FORM
SEAL
*SIZE TERMINATION
PIPE PER TABLE 7.
NOTE - Do not discharge exhaust gases directly into any chimney or vent stack. If ver­
tical 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 terminate as illus­
trated. 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 con­
densate piping in upflow applications. In horizontal applica­
tions, the condensate trap must extend below the unit. An
8" service clearance is required for the condensate trap.
Refer to figures 31 and 33 for condensate trap locations.
Figure 39 shows trap assembly using 1/2" PVC or 3/4"
PVC.
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 31) 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 appropri­
ate pipe dope.
3 - Install the cap over the clean out opening at the base
of the trap. Secure with clamp. See figure 39.
4 - Install drain trap using appropriate PVC fittings, glue
all joints. Glue the provided drain trap as shown in fig­
ure 39. Route the condensate line to an open drain.
Condensate line must maintain a 1/4" downward slope
from the furnace to the drain.
STRAIGHT-CUT OR
ANGLE-CUT IN DIRECTION
OF ROOF SLOPE *
3" - 8"
(76mm-
203mm)
SHOULDER OF FITTINGS
PROVIDE SUPPORT
OF PIPE ON TOP PLATE
SHEET
ALTERNATE
METAL TOP
INTAKE PIPE
PLATE
3" - 8"
(76mm-
203mm)
EXTERIOR
PORTION OF
CHIMNEY
CONDENSATE TRAP AND PLUG LOCATIONS
(Unit shown in upflow position)
1-1/2 in.
NOTE - In upflow applications where side return
air filter is installed on same side as the conden­
sate trap, filter rack must be installed beyond
condensate trap or trap must be re-located to
avoid interference.
5 - Figures 34 and 36 show the furnace and evaporator
coil using a separate drain. If necessary the conden­
sate line from the furnace and evaporator coil can
drain together. See figures 35, 37 and 38.
Upflow furnace (figure 37) - In upflow furnace applica­
tions 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 38) - In horizontal furnace
applications the field provided vent must be a mini­
mum 4" to a maximum 5" length above the condensate
drain outlet connection. Any length above 5" may re­
sult in a flooded heat exchanger if the combined pri­
mary 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 - Appropriately sized tubing and barbed fitting
may be used for condensate drain. Attach to the drain
on the trap using a hose clamp. See figure 32.
Page 23
Plug
(same on left side)
FIGURE 31