Measuring Chimney Liners

[cheechchi]

Hi All 1st time on here.
I have an old Scandia 320 Insert Woodburning stove which was my parents. It is in excellent condition and from what I remember it used to put out some serious heat. I know its not the highest quality stove but hey it looks good and it was free.

I am trying to figure out what size flu liner I need. My flu is really big approx. 8"X 14” . I know this is way to big. I want to know if it is necessary to insulate the liner too? Is there a calculation that I can figure out the size liner I need? The door opening is 14” high X 17” wide. The opening in the rear of the stove is 4.5"X14.5". Please help me out.
Cheech

 

[jtp10181]

For an old unit it probably use 8" liner but maybe one of the more seasoned members will know more specifically. Most of the units now come with a 6" round collar on them instead of a giant rectangular opening.

 

[thechimneysweep]

The liner size can be determined two ways: mathematically or practically.

Mathematically: the existing flue opening has a cross-sectional area of 65 sq.in, which would be the equivalent of a 9" round flue liner. The closest available liner size is 8" round.

Practically: I know of only one manufactured rectangle-to-round "boot" that will fit a 4.5 x 14.5 opening, and it converts to 8" round.