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VENT TERMINATION CLEARANCES
These instructions should be used as a guide-
line and do not supersede local codes in any
way. Install vent according to local codes,
these instructions, the current National Fuel
Gas Code (ANSI-Z223.1) in the USA or the
current standards of CAN/CGA-B149.1 and
-B149.2 in Canada.
Terminate multiple vent terminations according to
the installation codes listed above.
Terminate single vent caps relative to building
components according to Figure 5.
Vertical Vent Termination Clearances
TERMINATION HEIGHTS FOR VENTS ABOVE
FLAT OR SLOPED ROOFS
Horizontal Overhang
2 FT
MIN.
2 FT MIN.
Lowest
Discharge
Vent
Opening
Termination
H*
Storm Collar
12
Flashing
Roof Pitch is X/12
1 inch (25.4 mm) Minimum
Clearance to Combustibles
Concentric
*H = MINIMUM HEIGHT FROM ROOF TO
Vent Pipe
LOWEST DISCHARGE OPENING OF VENT
The vent / air intake termination clearances
above the high side of an angled roof is as
shown in the following chart:
Termination Heights For Vents
Above Flat Or Sloped Roofs
Ref. NFPA 54 / ANSI Z223.1, 7.6
Roof Pitch
* Feet
Flat to 6/12
1.0
6/12 to 7/12
1.25
7/12 to 8/12
1.5
8/12 to 9/12
2.0
9/12 to 10/12
2.5
10/12 to 11/12
3.25
11/12 to 12/12
4.0
12/12 to 14/12
5.0
14/12 to 16/12
6.0
16/12 to 18/12
7.0
18/12 to 20/12
7.5
20/12 to 21/12
8.0
Figure 5
Horizontal Vent Termination Clearances
The horizontal vent termination must have a minimum of 3" (76 mm) clearance to any overhead
combustible projection of 2 1/2" (64 mm) or less. For projections exceeding 2 1/2" (64 mm), see
Figure 6. All horizontal terminations may be located as close as 6" (152mm) to any combustible
exterior sidewall. This distance may be decreased to 2" (51mm) if the SV4.5HT-2 or SF4.5HT-2
termination is used and the exterior sidewall is non-combustible only. For additional vent location
restrictions refer to Figure 7 on Page 8.
greater than
Ventilated
Soffit
Vertical
Wall
18"
(457 mm)
X
Note - See Figure 33 on Page 20 for the exterior wall recess allowances of the square horizontal termination.
Figure 6
* Meters
0.3
0.38
0.46
0.61
0.76
0.99
1.22
1.52
1.83
2.13
2.29
2.44
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
Horizontal Vent Termination Clearances
Combustible Projection
2-1/2 inches or less in length
Combustible Projection
inches in length
2-1/2
Unventilated
Soffit
3"
(76 mm)
12"
(305 mm)
Termination Kit
All horizontal terminations
may be located as close
as 6" (152mm) to any
(non-combustible and
combustible) exterior
sidewall. This distance
may be decreased to
2" (51mm) for non-
combustible exterior
sidewalls only, if the
SV4.5HT-2 or SF4.5HT-2
termination
is used.
Termination Kit
Side Elevation View
7
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