42
RECOMMENDED SUPPORT FOR
VENT TERMINATION
It is recommended that sidewall vent terminations of over 24
inches (0.6 M) in length or rooftop vent terminations of over
36 inches (1 M) in length be supported by EITHER the
factory accessory vent termination kit or field--supplied
brackets or supports attached to the structure. A factory
accessory vent termination kit may be used for direct vent
terminations. Termination kits are available for 2--in. or 3--in.
pipe. See Table 10 for available options.
NOTICE
Table 10 – Vent Termination Kit for Direct Vent (2--pipe) Systems
Vent and
Combustion Air
Pipe Diameters
Approved Two- Pipe Termination Fittings
Allowable
Concentric Vent
Kit
1 1/2--in.
(38 mm)
2--in.
(51 mm)
2 1/2--in.
(64 mm)
3--in.
(76--mm)
4--in.
(102 mm)
1 1/2--in. (38 mm)
No
Yes
No
No
No
2--in. (51 mm)
2--in. (51 mm)
No
Yes
No
No
No
2--in. (51 mm)
2 1/2--in. (64 mm)
No
No
No
Yes
No
2--in. (51 mm)
3--in. (76 mm)
3--in. (76--mm)
No
No
No
Yes
No
3--in. (76 mm)
4--in. (102 mm)
No
No
No
Yes
Yes
3--in. (76 mm)
Direct Vent / 2-Pipe System
In a direct-vent (2-pipe) system, all air for combustion is taken
directly from outdoor atmosphere, and all flue products are
discharged to outdoor atmosphere. Combustion-air and vent pipes
must terminate together in the same atmospheric pressure zone,
either through the roof (preferred) or a sidewall. See Fig. 51 for
references to clearances required by National code authorities.
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. 40.
When sizing venting systems, the equivalent length of the
optional inlet pipe moisture trap must be taken into account.
NOTICE
Ventilated Combustion Air Systems
In a ventilated combustion air option, the vent terminates and
discharges the flue products directly to the outdoors similar to a
direct vent system. See Fig. 52 for references to clearances
required by National code authorities.
All air for combustion is piped directly to the furnace from a space
that is well ventilated with outdoor air (such as an attic or crawl
space) and the space is well isolated from the living space or
garage. Combustion air requirements for this option are the same
as the requirements for providing outside air for combustion for a
single pipe vent system. Refer to the “Air For Combustion and
Ventilation” Section.
OPTIONAL VENTING BELOW THE FURNACE
The venting system may be positioned below the furnace
ONLY
IF the factory accessory External Vent Trap Kit is used.
The External Vent Trap Kit is only approved for PVC/ABS
DWV venting systems.
CAREFULLY
FOLLOW
THE
INSTRUCTIONS
PROVIDED WITH THE EXTERNAL VENT TRAP KIT
FOR LAYING OUT THE VENTING SYSTEM AND
THE DRAIN SYSTEM.
The instructions included with this
furnace
DO NOT APPLY
to vent systems that are located
below the furnace.
NOTICE
CARBON MONOXIDE POISONING HAZARD
Failure to follow the instructions outlined below for each
appliance being placed into operation could result in carbon
monoxide poisoning or death.
The instructions included with this furnace
DO NOT APPLY
to vent systems that are located below the furnace.
CAREFULLY
FOLLOW
THE
INSTRUCTIONS
PROVIDED WITH THE EXTERNAL VENT TRAP KIT
FOR LAYING OUT THE VENTING SYSTEM AND
THE DRAIN SYSTEM
when all or part of the venting
system is placed below the furnace.
Proper configuration of the venting and drain system is critical
when placing all or part of the venting system below the level
of the furnace.
VENT GASSES COULD BE RELEASED
FROM THE DRAINAGE SYSTEM
if the instructions
provided with the External Vent Trap Kit are not followed.
!
WARNING
