10
When considering a masonry chimney, round tiles
are preferable to square or rectangular, as round tiles
have much better airflow characteristics and are far
easier to clean. Unfortunately, most North American
chimneys use square or rectangular tile liners that
are really designed for open fireplaces, not stoves or
furnaces. Of most importance, second only to overall
chimney height, is the diameter of the flue liner itself.
In most instances, it should be sized to the appliance;
i.e., 6" [152mm] flue outlet on the appliance requires
a 6" [152mm] chimney. The inner diameter should
never be less than the flue-outlet diameter and should
never be greater than 50% larger than the appliance
flue outlet. For example, do not expect a wood or
coal burning stove or furnace to function properly
if installed into a chimney with a flue greater than
50% more than the appliance outlet - - such as a 6"
[152mm] flue outlet requires a 6" [152mm] diameter
for optimum drafting, but can function well with an
8" [203mm], but becomes borderline beyond an 8"
[203mm] diameter.
Masonry chimneys built of concrete blocks with
or without flue liners do not meet modern building
codes. A solid fuel appliance must not be joined
to a chimney flue which is connected to another
appliance burning other fuels.
If your chimney has a typically oversized flue liner of,
say 8 x 12 (203mm x 305mm) inches, or greater, or if
it is unlined, it will be necessary for you to reline the
chimney, using any of the modern approved and
economical methods such as stainless steel, castable
refractory, or properly sized fireclay linings.
If you have any questions regarding venting your
appliance, feel free to contact the factory at the
address and phone number on this Owner's Manual.
You may also contact NFPA (National Fire Protection
Association) and request NFPA Standard 211 (1984
Edition-US). Another helpful publication is NFPA
Standard 908(US). Specify 1984 Edition of either of
the above US publications.
Venting Into A Masonry Chimney
