12 7034-277E May 5, 2015MT. VERNON AEF. Equivalent Feet of PipeThe table below can help you calculate the equivalent feetof pipe which is a method used to determine pellet vent size.Figure 12.12 ft.2 ft.3 ft.2 ft.Example of 3 Elbow-Rear Vent Termination CalculationPellet VentingComponent# ofElbowsFeet ofPipeMultipliedByEquivalentFeetComponentsEquivalent Feet90 o Elbow or Tee 3 X 5 1545 o Elbow X 3Horizontal Pipe 7 X 1 7Vertical Pipe 2 X 0.5 1Total Equivalent Feet 23Note: This is a generic example and is notintended to represent any specific fuel type.Vent surfaces get HOT, can cause burns iftouched. Non-combustible shielding or guardsmay be required.WARNINGFigure 12.23 in. or 4 in. (76mm or 102mm) Diameter PipeEquivalent PipeLength In FeetALTITUDE IN THOUSANDS OF FEET020301 2 3 4 5 6 7 8 9 104 in. (102mm) Diameter Pipe Only10Example 1Example 2Example 1: If the equivalent length of pipe is 23 feet (7m) withaltitude of 8,000 feet (2438m) you must use 4 inch (102mm)diameter type “L” or “PL” vent.Example 2: If the equivalent length of pipe is 12 feet (3.7m)with altitude of 6,000 feet (1829m) you may use 3 or 4 inch(76 to 102mm) diameter type “L” or “PL” vent.G. Pipe Selection ChartThe chart will help you in determining proper venting sizeaccording to the equivalent feet of pipe calculated previouslyand the altitude above sea level of this installation.Figure 12.2a. Locate the calculated equivalent feet of pipe on the verticalleft side of the chart.b. Move to the right horizontally on the chart until you reachyour altitude above sea level.c. If you fall below the diagonal line, 3 or 4 inch (76 to 102mm)pipe may be used.d. If it is anywhere above the diagonal line, a 4 inch (102mm)diameter pipe is required.NOTICE:• A 90° elbow is 5 times as restrictive to the flow of exhaustgases under positive pressure as 1 foot (305mm) of hori-zontal pipe.• A foot of horizontal pipe is twice as restrictive as a foot ofvertical pipe.Figure 12.1WARNINGRISK OF INJURY OR PROPERTY DAMAGE!• Improper installation, adjustment, alteration, service or main-tenance can cause injury or property damage.• Refer to the owner’s information manual provided with thisappliance.• For assistance or additional information consult a qualifiedinstaller, service agency or your dealer.Fire Risk.• Only LISTED venting components may be used.• NO OTHER vent components may be used.• Substitute or damaged vent components may impair safeoperation.WARNING