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other requirements to and/or exemptions from the National codes
shown in the figures.
Roof termination is the recommended termination location. Roof
terminations provide better performance against sustained
prevailing winds. The roof location is preferred since the vent and
combustion
air system is less susceptible
to damage or
contamination. The termination is usually located away from
adjacent structures or other obstacles such as inside corners,
windows, doors or other appliances. It 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. 55 or
Fig. 56 per application.
2. The vent termination must be located at least 3 feet from an
inside corner and follow the clearance distances in the In-
side Corner Termination drawing.
3. Termination or termination kit should be positioned where
vent vapors will not damage plants/shrubs, air conditioning
equipment or utility meters.
4. Do not locate termination directly into prevailing winds.
Termination should be positioned so that it will not be
affected by sustained prevailing winds over 30 mph, wind
eddy, such as inside building corners, or by recirculation of
flue gases, airborne leaves, or light snow.
5. Termination or termination kit should be positioned where it
will not be damaged by or subjected to foreign objects such
as stones, balls, etc.
6. Termination or termination kit should be positioned where
vent vapors are not objectionable
.
Direct Vent / 2-Pipe System
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.
For all venting configurations for this appliance and other gas
appliances placed into operation for the structure, provisions
for adequate combustion, ventilation, and dilution air must be
provided in accordance with:
U.S.A. Installations
: Section 9.3 of the current edition of
NFPA 54/ANSI Z223.1 Air for Combustion and Ventilation
and applicable provisions of the local building codes.
Canadian Installations
: Part 8 of the current edition of
CAN/CSA--B149.1. Venting Systems and Air Supply for
Appliances and all authorities having jurisdiction.
!
WARNING
Direct vent (2--pipe) vent and combustion air pipes must terminate
outside the structure. See Fig. 55 For references to vent clearances
required by National code authorities.
Allowable vent and
combustion air terminations are shown in Fig. 41.
Abandoned masonry
used as raceway
(per code)
12 in. (305 mm) min. from
overhang or roof
Maintain 12 in. (305mm)
minimum clearance
above highest anticipated
snow level or grade
whichever is greater.
Side wall termination
with 2 elbows (preferred)
12 in. min. (305 mm)from
overhang or roof
Maintain 12 in. (305mm)
minimum clearance
above highest anticipated
snow level or grade
whichever is greater
6 in. (152mm) minimum clearance
between wall and end of vent pipe.
10 in. (254mm) maximum pipe length
Sidewall Termination
with Straight Pipe (preferred)
Roof Termination (Preferred)
Vent
Maintain 12 in
.
minimum clearance
above highest anticipated
snow level maximum of
24 in. (610mm) above roof
.
90
°
(305mm)
A05091
Fig. 40 -- Vent Pipe Termination for Non--Direct Vent and Ventilated Combustion Air System