Carrier PG96MSA Installation, Start-Up, Operating And Service And Maintenance Instructions page 38

PG96MSA: Installation, Start-up, Operating and Service and Maintenance Instructions
Fig. 48 – Alberta and Saskatchewan Vent Termination
Size the Vent and Combustion Air Pipes
General
Furnace combustion air and vent pipe connections are sized for 2-in. (50
mm ND) PVC/ABS DWV pipe. The combustion air and vent pipe
connections also accommodate 60 mm polypropylene venting systems
with outside diameters of approximately 60 mm (2-3/8 inches). Any pipe
diameter change should be made outside furnace casing in vertical pipe.
Any change in diameter to the pipe must be made as close to the furnace
as reasonably possible. See Fig.
The Maximum Vent Length for the vent and combustion air pipe (when
used) is determined from the Maximum Equivalent Vent Length in
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
49.
Table 14 minus the number of fittings multiplied by the deduction for
each type of fitting used from
NOT IN
HORIZONTAL
SECTION
Fig. 49 – Combustion Air and Vent Pipe Diameter Transition
Location and Elbow Configuration
Recommended Combustion Air Inlet Moisture Trap
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 Fig.
When sizing venting systems, the equivalent length of the optional
moisture trap (15 feet/5 M) must be taken into account.
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. See Fig.13. 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
casing. See Fig. 50.
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.
A13078A
38
Table 15.
FURNACE
PIPE DIAMETER
TRANSITION IN
VERTICAL SECTION
NOTICE
!
50.
Fig.
A93034
50.