VERTICAL SIDEWALL INSTALLATIONS
Since it is very important that the venting system maintain its balance between the combustion air intake and the flue gas exhaust, certain limitations as to vent configurations apply and must be strictly adhered to.
The graph showing the relationship between vertical and horizontal side wall venting will help to determine the various lengths allowable. Fig. 11a or 11b.
Minimum clearance between vent pipes and combustible materials is one (1") inch (25mm) on top, bottom and sides unless otherwise noted.
When vent termination exits through foundations less than 20" below siding outcrop, the vent pipe must flush up with the siding. A 7DVSS must also be used.
It is always best to locate the fireplace in such a way that minimizes the number of offsets and horizontal vent length.
The horizontal vent run refers to the total length of vent pipe from the flue collar of the fireplace to the face of the outer wall.
For each 45 degree elbow installed in the hori- zontal run, the length of the horizontal run MUST be reduced by 18" (45cm). This does not apply if the 45 degree elbows are installed on the vertical part of the vent system.
The maximum number of elbow degrees in a system is 270o (See Fig. 8).
Sample: | 1 | - |
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| 90o |
| 2 | - |
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| 45o |
| 3 | - |
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| 45o |
| 4 | - |
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| 90o |
| Total |
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| 270o |
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Fig. 8
Horizontal plane means no vertical rise exists on this portion of the vent assembly.
VERTICAL SIDEWALL APPLICATIONS
The maximum number of 90 degree elbows per side wall installation is three (3).
For D232 the maximum horizontal run off a minimum 12" vertical rise is 3'. (See Fig. 9)
3 FT |
(92cm) |
x |
D232x=12" |
Fig. 9 |
7.5 ft. |
2286mm |
A + B = 17ft. |
Fig. 10 |
If a 90 degree elbow is used in the horizontal vent run (level height maintained) the maximum horizontal vent length is reduced by 36 inches. Fig. 10. This does not apply if the 90 degree elbows are used to increase or redirect a vertical rise (Fig. 11).
Example: According to the chart the maximum horizontal vent length is 20' and if a 90 degree elbow is required in the horizontal vent it must be reduced to 17'.
(Fig. 10 Dimension A plus B must not be greater than 17').
The maximum number of 45 degree elbows permitted per side wall installation is two (2). These elbows can be installed in either the vertical or horizontal run (Fig. 8).
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| 20 FT |
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| (610cm) |
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| PIPE STRAPS |
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| EVERY 3' |
(2286m) |
| (92cm) |
| FIRESTOP/ZERO | |
7.5FT | PIPE STRAPS | CLEARANCE SLEEVE |
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EVERY 3' |
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| (92cm) |
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| Fig. 11 |
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