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Quadra-Fire • Hudson Bay • 7003-121_R20 • 11/14
D.
How to Use the Vent Graph
1. Measure the distance from the top of appliance to the
center of the 90° elbow. On the graph below, draw a
horizontal line from that measurement on the vertical
axis across until it intersects with the slanted line.
2. From the point of this intersection, draw a vertical line to
the bottom of the graph.
3. The point at which this line meets the bottom line of the
graph is the maximum length of the horizontal run.
Example 1:
If the vertical dimension from the top of the
appliance is to the center of the 90° elbow is 7 ft. (2m), the
horizontal run to the outer wall flange must not exceed 12
ft. (4m).
Example 2:
If the vertical dimension from the top of the
appliance is 21 ft. (6m), the horizontal run to the outer wall
flange must not exceed 9 ft. (3m).
4. Each 90° elbow is equivalent to 3 ft. (914mm) of vent pipe
and each 45° elbow is equivalent to 1 ft. (305mm) of vent
pipe, and must be subtracted from vent pipe run. A single
vertical to horizontal 90° elbow is already calculated
into the allowable 15 ft. (5m) run. Each additional 90°
elbow reduces the maximum horizontal distance by 3 ft.
(914mm).
Example: The use of 3 elbows would reduce the
allowable horizontal run to 9 ft. (3 - 1 = 2 elbows x 3 ft. =
6 ft.; 15 ft. max. - 6 ft. = 9 ft. max.)
E.
Venting Guidelines
NOTES
The maximum horizontal vent run is 15 ft. (5m) with a
minimum vertical vent rise of 10 ft. (3m).
The minimum horizontal vent run is 11 in. (279mm).
Minimum wall thickness is 4 in. (102mm). Maximum wall
thickness is 20 in. (508mm).
Horizontal sections require a 1/4 in. (6mm) rise for every 12
in. (305mm) of horizontal travel.
Exterior Vent Diameter = 6 5/8 in. (168mm); Inner Vent
Diameter = 4 in. (101mm)
Horizontal sections require noncombustible support every 3
ft. (914mm), e.g. wall straps.
Maximum 90° elbows for horizontal termination is 3.
Maximum 90° elbows for vertical termination is 4.
NOTE:
IF YOUR INSTALLATION FALLS WITHIN A SHADED
AREA ON THE GRAPH, THE DAMPER MUST BE USED.
(
In the Commonwealth of Massachusetts, the word damper
shall be replaced with the words flue restrictor.)
Figure 5.2
VERTICAL DISTANCE
FROM APPLIANCE TO
TO THE 90° ELBOW
TOTAL HORIZONTAL RUN TO OUTSIDE OF ExTERIOR WALL (INCLUDING ELBOWS)
EX. 2
EX. 1
11" 2' 4' 6' 8' 10' 12' 14' 15'
30'
28'
26'
24'
22'
20'
18'
16'
14'
12'
10'
8'
6'
4'
2'
0'
(MAX)
(MIN)
40'
38'
36'
34'
32'
