Vent Pipe Sizing Worksheet - Lennox G61MPV?36B?045 Installation Instructions Manual

Vent Pipe Sizing Worksheet

Step 1 Proposed vent pipe size : ______
Step 2 Termination kit catalog number : _____________
Vent pipe equivalency value from table 5 : ______
Step 3 Total number of 90° elbows required (indoors and outdoors)
______ X 5 = ______ equivalent feet of pipe
Step 4 Total number of 45° elbows required (indoors and outdoors)
______ X 2.5 = ______ equivalent feet of pipe
Step 5 Linear feet of straight pipe required : ______
Add equivalent feet of vent pipe listed in
Step 6
steps 2 through 5.
If the total is equal to, or less than, the allowable maximum given in table 7, the proposed pipe size is acceptable. If the
total exceeds the maximum allowed vent pipe length, repeat the process above using the next larger diameter pipe until
an acceptable total is achieved.
NOTE − In Direct Vent systems, total the equivalent length of either the exhaust OR intake piping run, depending upon which
will be LONGER. Intake and exhaust pipe diameter must be the same size and must be terminated in the same pressure
zone. Intake and exhaust pipe should be roughly the same length.
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Equivalent Feet
TOTAL