Pipe Calculation
This page is to help you determine what you need for a complete flue system.
A complete flue system requires;
- 3" double wall flue pipes ( 22.5" of usable flue pipe, 1.5" loss )
- An exit kit to exit the flue pipe ( 23" of usable flue pipe, 1" loss )
- Enough 5" insulated pipe to insulate the 3" as it goes through the ceiling, roof and to outside.
- Keep in mind that the exit kit comes with either a 24" section of 5" pipe or 2 x 12" 5" pipes. They do NOT come with any 3" pipe.
The amount of pipe needed depends on the height the stove is installed, the distance needed to pass the highest point by one foot and the placement of the stove itself.
Please see below how to calculate the pipe for a flat, round and pitched roof.

The pipe begins where the top of the stove is located.
The stove will heat below it. This is just to show the difference that the installation height has on efficiency.
Difference Between Installation Height

Van / Flat Roof
3" Double Wall Flue Pipe
A - B + 12" = Total length of 3" double wall flue pipe in inches.
Total length of 3" double wall flue pipe in inches divided by 22.5 = # of 24" long sections.
5" Insulated Pipe
12" + 2" + C = Total length of 5" insulated pipe in inches.
Total length of 5" insulated pipe in inches divided by 23" = # of 24" long sections
( 12" sections available as well)

Schoolie / Curved Roof
3" Double Wall Flue Pipe
A - B + 12" = Total length of 3" double wall flue pipe in inches.
Total length of 3" double wall flue pipe in inches divided by 22.5 = # of 24" long sections.
5" Insulated Pipe
12" + 2" + C = Total length of 5" insulated pipe in inches.
Total length of 5" insulated pipe in inches divided by 23" = # of 24" long sections
( 12" sections available as well)

Amount of 5" Insulated Pipe Needed in relation To The Peak
The closer the pipe exits from the peak the less insulated pipe you will require.

Pitched Roof
3" Double Wall Flue Pipe
A - B + 12" = Total length of 3" double wall flue pipe in inches.
Total length of 3" double wall flue pipe in inches divided by 22.5 = # of 24" long sections.
5" Insulated Pipe
12" + 2" + C = Total length of 5" insulated pipe in inches.
Total length of 5" insulated pipe in inches divided by 23" = # of 24" long sections
( 12" sections available as well)
Calculation Example

3” double wall pipe
120” - 36” + 12”=96"
96” ÷ 22.5” = 4.26 sections
Requiring;
4 x 24” long sections
1 x 12” long section
5” insulated pipe.
12” + 2” + 24”= 38”
38” ÷ 23” = 1.65 sections
Requiring;
2 x 24” long sections (exit kit comes with one)