30786-7-0415
Page 20
to Use the vent Graph (Figure 22)
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: (top vent connections with vertical
termination).
If the vertical dimension from the floor of the unit is 35
feet, the horizontal run to the outer wall flange must not
exceed 6.5 feet.
eXAMpLe B: (top vent connections with vertical
termination)
If the vertical dimension from the floor of the unit is 6.5
feet, the horizontal run to the outer wall flange must not
exceed 14.5 feet.
speciAL nOte:
For each 45 degree elbow installed in
the horizontal 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. Reduce 3' for every 90° elbow.
example:
According to the chart the maximum horizontal
vent length is 20' and if two 45 degree elbows are required
in the horizontal vent it must be reduced to 17'.
Note: The maximum number of 90 degree elbows
permitted per rear vent take-off is two. Both elbows must
be installed in the vertical orientation.
note:
On vertical venting the first elbow is not counted.
Figure 22
Acceptable vertical and horizontal vent run.
Rigid Venting - 40' maximum vertical and 20' maximum
horizontal
Flex Venting - 35' maximum vertical and 20' maximum
horizontal
Unacceptable vertical and horizontal vent run.
TOP EXIT - VERTICAL AND HORIZONTAL TERMINATION
(DIMENSIONS IN FEET)
NOTE: FLEX VENT
MAXIMUM HEIGHT
IS 35 FEET
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
TION
CAPS
TOP VENT
CONNECTION
TOP VENT CONNECTION
OF VENTING WITH
HORIZONTAL TERMINATION
HORIZONTAL RUN
venting Graph (Dimensions in Feet)
ventinG FirepLAce - tOp
