Table of Contents
Advertisement
Multistory and common venting are prohibited.
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. A factory accessory vent
termination kit MUST be used in a direct vent (2-pipe) system.
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. A factory-supplied perforated
disk assembly (in loose parts bag) MUST be used in
combustion-air pipe elbow.
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each appliance
connected to the venting system being placed into operation
could result in carbon monoxide poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into operation,
while all other appliances connected to the venting system
are not in operation:
1. Seal any unused openings in venting system.
2. Inspect the venting system for proper size and
horizontal pitch, as required in the National Fuel Gas
Code, ANSI Z223.1-2006/NFPA 54-2006 or the
CSA B149.1, Natural Gas and Propane Installation
Code and these instructions. Determine that there is
no blockage or restriction, leakage, corrosion and
other deficiencies, which could cause an unsafe
condition.
3. As far as practical, close all building doors and
windows and all doors between the space in which
the appliance(s) connected to the venting system are
located and other spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not
connected to the venting system. Turn on any
exhaust fans, such as range hoods and bathroom
exhausts, so they are operating at maximum speed.
Do not operate a summer exhaust fan.
6. Follow the lighting instructions. Place the appliance
being inspected into operation. Adjust the thermostat
so appliance is operating continuously.
7. Test for spillage from draft hood equipped appliances
at the draft hood relief opening after 5 minutes of
main burner operation. Use the flame of a match
or candle.
8. If improper venting is observed during any of the
above tests, the venting system must be corrected in
accordance with the National Fuel Gas Code, ANSI
Z223.1-2006/NFPA 54-2006 and/or CSA B149.1,
Natural Gas and Propane Installation Codes.
9. After it has been determined that each appliance
connected to the venting system properly vents when
tested as outlined above, return doors, windows,
exhaust fans, fireplace dampers and any other
gas-fired burning appliance to their previous
conditions of use.
MATERIALS
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 7 for approved materials for use in
the U.S.A.
!
FIRE AND EXPLOSION HAZARD
Failure to follow this warning could result in property damage,
personal injury, or death.
Solvent cements are combustible. Keep away from heat,
sparks, and open flame. Use only in well-ventilated areas.
Avoid breathing in vapor or allowing contact with skin
or eyes.
In Canada, construct all combustion-air and vent pipes for this
unit of CSA or ULC listed schedule-40 PVC, PVC-DWV or
ABSDWV pipe and pipe cement. SDR pipe is NOT approved
in Canada.
In direct vent (2-pipe) systems, combustion air and vent pipes
must terminate together in same atmospheric pressure zone,
either through roof or sidewall (roof termination preferred), using
accessory termination kit. See Table 8 for required clearances.
In non-direct vent (1-pipe) system, vent pipe termination must be
installed with adequate clearances to building openings and
equipment to comply with national and local codes. See Table 9
for required clearances.
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in property damage,
personal injury, or death.
All combustion-air and vent pipes must be airtight and
watertight. Pipes must also terminate exactly as shown in Fig.
42 for direct vent (2-pipe) system and Fig. 43 for non-direct
vent (1-pipe) system.
An abandoned masonry chimney may be used as a raceway for
properly
insulated
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. 42 for Direct Vent (2-Pipe) system and Fig. 43 for
Non-Direct Vent (1-Pipe) system.
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.
!
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent
unit operation.
When vent pipe is exposed to temperatures below freezing,
such as when it passes through an unheated space or when a
chimney is used as a raceway, pipe must be insulated as
shown in Table 10 with Armaflex-type insulation.
Furnace combustion air and vent pipe connections are sized for
2-in. (51 mm) pipe. Any pipe size change should be made outside
furnace casing in vertical pipe. The transition has to be made as
close to the furnace as reasonably possible.
COMBUSTION AIR PIPE
General
Furnace combustion-air connection must be attached as shown in
Fig. 37. Combustion-air intake housing plug may need to be
relocated in some applications.
- - 32 - -
WARNING
WARNING
and
supported
combustion-air
CAUTION
(when
Advertisement
Table of Contents
