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General
If this furnace replaces a furnace that was connected to a vent
system or chimney, the vent or vent connectors of other remaining
appliances may need to be re- -sized. Vent systems or vent
connectors of other appliances must be sized to the minimum size
as determined using appropriate table found in the current edition
of National Fuel Gas Code NFPA 54/ANSI Z- -223.1. In Canada,
refer to CAN/CSA- -B149.1.
An abandoned masonry chimney may be used as a raceway for
properly
insulated
and
supported
applicable) and vent pipes. Each furnace must have its own set of
combustion- -air and vent pipes and be terminated individually, as
shown in Fig. 40 for Direct Vent (2- -Pipe) system, or Fig. 41 for
single- -pipe or ventilated combustion air option.
A furnace shall not be connected to a chimney flue serving a
separate appliance designed to burn solid fuel.
Other gas appliances with their own venting system may also use
the abandoned chimney as a raceway providing it is permitted by
local code, the current edition of the National Fuel Gas Code, and
the vent or liner manufacturer's installation instructions. Care must
be taken to prevent the exhaust gases from one appliance from
contaminating the combustion air of other gas appliances.
Do not take combustion air from inside the chimney when using
ventilated combustion air or single- -pipe vent option.
These furnaces can be vented as direct- -vent (two- -pipe), ventilated
combustion air or non-direct (single- -pipe) vent system. Each type
of venting system is described below. Common venting between
these furnaces or other appliances is prohibited.
Materials
U.S.A.
Combustion air and vent pipe, fittings, primers, and solvents must
conform to American National Standards Institute (ANSI)
standards and American Society for Testing and Materials (ASTM)
standards. See Table 17 for approved materials for use in the
U.S.A. This furnace is also CSA approved for venting with M&G
DuraVentR PolyProR polypropylene venting systems.
Canada
Special Venting Requirements for Installations in Canada,
Installation in Canada must conform to the requirements of
CAN/CSA B149 code. Vent systems must be composed of pipe,
fittings, cements, and primers listed to ULC S636. M&G DuraVent
PolyPro polypropylene venting systems are ULC S636 listed.
NOTE: When using polypropylene venting systems, all venting
materials used, including the vent terminations must be from the
same manufacturer.
Venting Systems
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. 44 for
references to clearances required by National code authorities.
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 Fig. 51.
When sizing venting systems, the equivalent length of the
optional inlet pipe moisture trap must be taken into account.
combustion- -air
(when
34
NOTICE
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
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.
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. 45 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.
Non-Direct Vent (1-pipe) System
In a non direct-vent (1-pipe) system, all air for combustion is taken
from the area adjacent to furnace, and all flue products are
discharged to outdoor atmosphere. Air for combustion must be
supplied as described in the Air For Combustion and Ventilation
Section. Do not use an abandoned chimney to supply outside air to
the furnace. See Fig. 45 for references to vent clearances required
by National code authorities.
A combustion air pipe to the outdoors is not required for a
single- -pipe vent system. A 12-in. (304 mm) long pipe with a 2- -in.
(51 mm) tight radius 90 degree elbow is required to be attached to
the combustion air pipe adapter on the furnace. See Fig. 50. This
short inlet air pipe helps to ensure stable combustion, as well as
allow for sound attenuation. To aid sound attenuation, point the
inlet air pipe away from occupants. An extra elbow and/or five
feet of pipe may be used to accomplish the sound attenuation
function.
WARNING
!
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
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.
THE
INSTRUCTIONS
THE
INSTRUCTIONS
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