Lennox Hearth 775 - Manual (Page 10)

NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
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Figure 13 Figure 14 Horizontal Run (in feet)
V
ertical Run (in feet)
Measure from the appliance fl
ue collar to the top of the vent pipe
Unacceptable
Venting
Confi guration
Vertical Terminations Must
be in this area
V
ertical Run (in feet)
Measure from the appliance fl
ue collar to the top of the vent pipe
Horizontal Run (in feet)
May use up to three 90
degree elbows
One 90
degree
elbow
Unacceptable
Venting
Confi guration
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The vent must rise vertically, a minimum of 24" (610 mm) off the
top of the appliance for Natural Gas and 36" for Propane Gas before
the fi rst elbow.
The horizontal run may extend up to 20 feet ( 6 meters) and include
a vertical rise of up to 40 feet (12 meters) - see Figure 13. Horizontal
termination must meet the criteria shown in Figures 4 and 5.
• Approved vent systems must terminate above and including the
heavy line in Figure 13.
• Two 45 degree elbows may be substituted for each single 90 degree
elbow.
• With a rise between 2 feet to 5 feet, one 90 degree or two 45 degree
elbows may be used.
A vertical vent system must terminate no less than 8 feet ( 2.44 meters)
and no more than 40 feet / 12 meters ( above the appliance fl ue collar.
See Figure 14.
A vertically terminated vent system must also conform to the follow-
ing criteria:
No more than three 90 degree elbows may be used.
Two 45 degree elbows may be substituted for one 90 degree elbow. No
more than six 45 degree elbows may be used.
Vent must rise a minimum of 2 feet before an offset is used.
Termination height must conform to roof clearance as specifi ed in
Figure 3
Horizontal Termination Vertical Termination