43
Table 12 – Vent Termination Kit for Direct Vent (2--pipe)
Systems
DIRECT VENT
(2---PIPE)
TERMINATION KIT
TERMINATION
SYSTEM
DIAM. OF COMBUS-
TION AIR AND VENT
PIPES --- IN. (mm)
2---in. (51 mm)
Concentric Vent Kit
Single Penetration of
Wall or Roof
1, 1---1/2, 2, or 2---1/2
(24, 36, 51, 64 mm)
3---in. (76 mm)
Concentric Vent Kit
Single Penetration of
wall or Roof
2---1/2, 3 or 4
(64, 76, 102 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. 45 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. 52.
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. 46 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
Locating the Vent Termination
General
NOTE:
Termination Requirements for the Provinces of
Alberta and Saskatchewan are located at the end of this
section.
Combustion--air inlet pipe (direct vent/2--pipe system only) and
vent pipe must terminate outside structure, either through sidewall
or roof.
For vent termination clearance, references to National codes are
shown in Fig. 45 for Direct Vent/2--Pipe system and Fig. 46 for
Ventilated Combustion Air system. For exterior termination
arrangements, refer to Fig. 47 for Direct Vent/2--Pipe system and
Fig. 48 for Ventilated Combustion Air system. Contact Local code
authorities for other requirements to and/or exemptions from the
National codes shown in the figures.
Roof termination is often preferred since it is less susceptible to
damage or contamination, is usually located away from adjacent
structures, is less prone to icing conditions, and it often has less
visible vent vapors. Sidewall terminations may require sealing or
shielding of building surfaces with a corrosive resistance material
due to the corrosive properties of combustion products from the
vent system, as well as protection of adjacent structures.
RECOMMENDED SUPPORT FOR
VENT TERMINATIONS
It is recommended that sidewall vent terminations in excess of
24 inches (0.6 M) or rooftop terminations in excess of 36
inches (1 M) in vertical length be supported by
EITHER
the
Direct Vent Termination Kit shown in Table 12 or by
field--supplied brackets or supports fastened to the structure.
NOTICE
When determining appropriate location for termination, consider
the following guidelines:
1. Comply with all clearance requirements stated in Fig. 45 or
Fig. 46 per application.
2. Termination or termination kit should be positioned where
vent vapors will not damage plants/shrubs or air condi-
tioning equipment.
3. Termination or termination kit should be positioned so that
it will not be affected by wind eddy, such as inside building
corners, nor by recirculation of flue gases, airborne leaves,
or light snow.
987MA
