White Mountain Hearth DVCX(36,42)FP30(N,P)-2 Installation Instructions And Owner's Manual page 23

VENTING GRAPH (Dimensions in Feet)
Acceptable vertical and horizontal vent run.
(40' maximum vertical and 20' maximum horizontal)
Unacceptable vertical and horizontal vent run.
See Figure 36 on Page 24 for A, B and C examples.
35009-2-1015
VENTING FIREPLACE
Figure 35
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 unit in
accordance with same.
EXAMPLE A:
If the vertical dimension from the floor of the unit 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 unit is 24 feet, the
horizontal run to the outer wall flange must not exceed 10 feet.
EXAMPLE C:
If the horizontal run to the outer wall flange is 17 feet, the vertical
dimension from the floor of the unit to the center of the termination
must not be less than 7 feet 6 inches.
SPECIAL NOTE: 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.
Note: On vertical venting the first elbow does not get counted.
Note: 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 2-foot section of horizontal vent before the termination.
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