935SA: Installation, Start-up, Operating and Service Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
31
Any change in diameter to the pipe must be made as close to the furnace
as reasonably possible (see
).
The Maximum Vent Length for the vent and combustion air pipe (when
used) is determined from the Maximum Equivalent Vent Length
) minus the number of fittings multiplied by the deduction for
each type of fitting used (
).
A200089
NOTE:
Only connect combustion air inlet moisture drain downstream
of the furnace trap assembly as shown.
A170122A
Fig. 43 – Recommended Combustion Air Inlet Moisture Trap
A12220
Representative drawing only, some models may vary.
Fig. 44 – Sample Inlet Air Pipe Connection for Polypropylene
Venting Systems
A93034
Fig. 45 – Combustion Air and Vent Pipe Diameter Transition
Location and Elbow Configuration
Recommended Combustion Air Inlet Moisture Trap
Recommended to prevent moisture from trickling into the furnace
vestibule, a trap can be installed in the intake air pipe near the furnace.
To prevent moisture, connecting a drain line to the trap is recommended
as trace amounts of moisture will evaporate into the intake air stream. If
the combustion air inlet is located near a moisture exhaust duct, or there
are other concerns of excessive moisture being drawn into the
combustion air inlet, it is encouraged to connect a drain line to the trap.
The trap can be constructed from a running tee of the same diameter of
the intake air pipe with
EITHER
a removable cap attached to a 6-inch
long pipe connected to the tee or the External Vent Trap Kit to help
prevent contaminants from entering the furnace (see
).
The External Vent Trap Kit accessory may be used as a trap for the
combustion air inlet pipe if a large amount of moisture must be removed.
The drain line may be connected to the same drain as the furnace
condensate and the evaporator coil condensate line
ONLY
if the inlet air
trap drain and the evaporator coil drain empty into an open segment of
pipe above the drain. The drain line must be connected downstream of
the condensate trap float switch (see
). When using the External
Vent Trap Kit, refer to those instructions for proper drain connections.
The tee may also be connected to the intake air pipe on the side of the
).
In any configuration, it will be necessary to add the equivalent length of
the tee (15 feet/5 M) to the Total Equivalent Vent Length of the venting
system.
NOTICE
!
OPTIONAL CONFIGURATION FOR COMBUSTION
AIR INLET PIPE
In applications where there is a risk of excessive moisture entering the
combustion air inlet pipe, a moisture trap may be added to the inlet pipe
to help prevent moisture from entering the furnace from the combustion
air inlet pipe. (see
).
When sizing venting systems, the equivalent length of the optional
moisture trap (15 feet/5 M) must be taken into account.
Representative drawing only, some models may vary in appearance.
TO CODE--APPROVED DRAIN OR CONDENSATE PUMP
Tee
Dry Well
Cap
(water tight
and removable)
Tee
Dry Well
Cap
(water tight
and removable)
Tee
Dry Well
Cap
(water tight
and removable)
Recommend “T” fitting with 4--inch minimum height standpipe (
A
) of same diameter or larger extending upward.
A
A
A
EXAMPLE FOR
UPFLOW INSTALLATIONS.
MAY BE APPLIED TO
OTHER CONFIGURATIONS.
FURNACE
NOT IN
HORIZONTAL
SECTION
PIPE DIAMENTER
TRANSITION IN
SECTION
