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NOTICE: The initial 45° elbow is considered to be part of the
fireplace and does not factor in the venting calculations.
To Use the Vent Graph
1. Determine the height of the center of the horizontal vent
pipe. Using this dimension on the Sidewall Vent Graph,
locate the point it intersects with the slanted graph line.
2. From the point of this intersection, draw a vertical line to the
bottom of the graph.
3. Select the indicated dimension, and position the fireplace in
accordance with same.
EXAMPLE A:
If the vertical dimension from the floor of the fireplace is 32 feet,
the horizontal run to the outer wall flange must not exceed 5 feet.
EXAMPLE B:
If the vertical dimension from the floor of the fireplace is 24 feet,
the horizontal run to the outer wall flange must not exceed 10
feet.
EXAMPLE C:
If the vertical dimension from the floor of the fireplace is 7 feet,
the horizontal run to the outer wall flange must not exceed 15
feet.
SPECIAL NOTICE:
For each 45° elbow installed in the horizontal
run, the length of the horizontal run MUST be reduced by
18 inches. Reduce 3 feet for every 90° elbow. This does not
apply if the 45° elbows are installed on the vertical part of the
vent system.
Example:
According to the chart the maximum horizontal
vent length is 20 feet and if two 45° elbows are required in the
horizontal vent it must be reduced to 17 feet.
The maximum number of 45° elbows permitted per side wall
installation is two. These elbows can be installed in either the
vertical or horizontal run.
The maximum number of 90° elbows in a vent run is three.
NOTICE:
When figuring horizontal run length, the first elbow
does not get counted. This is not referring to the initial 45° elbow
which is considered to be part of the fireplace.
NOTICE:
A horizontal vent with the minimum required vertical
rise (using a 12 inch section of vent before the elbow) will use
a maximum of a 9 inch section of horizontal vent before the
termination.
Figure 41
Acceptable vertical and horizontal vent run.
(40ft maximum vertical and 20ft maximum horizontal)
Unacceptable vertical and horizontal vent run.
VENTING GRAPH (Dimensions in Feet)
A
C
B
HORIZONTAL RUN
VER
TICAL
DIMENSION FROM
THE BOTT
OM OF
THE UNIT
T
O
THE CENTER OF
THE
FLUE OUTLET
WITH VER
TICAL
OR HORIZONT
AL
TERMINA
TIONS CAPS
VENTING GRAPH
VENTING FIREPLACE - TOP