Venting
Chimney connectors shall not pass through an attic or roof space, closet or similar concealed space, or a floor or ceiling. Where passage
through a wall, or partition of combustible construction is necessary, the installation shall conform to
CAN/CSA-B365, Installation
Code for Solid-Fuel-Burning Appliances and Equipment.
Where an existing chimney is used, it must be large enough to provide a draft adequate for removing gaseous products of combustion.
From NFPA 2 20 3:
. The cross-sectional area of the chimney system must not be less than that of the flue collar. (For The Mark I and Mark III
served by a round chimney, the diameter must be at least 6 inches)
2. Chimney systems which are completely internal below the roofline must be no more than three times the crosssectional area
of the flue collar (28.3 in2 X 3 = 84.8 in2).
3. Chimney systems which are exposed to the exterior on one or more sides below the roofline must be no more than two times
the cross-sectional area of the flue collar (28.3 in2 X 2 = 56.5 in2).
3. Venting and Chimneys
3.1 TYPES OF CHIMNEYS
The chimney is one of the most important, yet the most neglected and misunderstood portion of any solid fuel burning appliance
installation. Do not connect your stove to a chimney flue that already serves another heating device.
Under no circumstances should a manual flue damper be installed in the smoke pipe between the stove and the chimney.
There are three types of “Class A” chimneys:
. Masonry with a tile liner, including brick, block, stone, etc. It must be supported by a ground-level foundation.
2. Insulated “Class A” manufactured chimney, listed and certified by a national test agency.
3. Triple-walled metal “Class A” chimney, listed and certified by a national test agency.
If your masonry chimney has not been used for some time, have it inspected by a qualified person (building inspector, fire department
personnel, etc.). If a listed and certified manufactured chimney is to be used, make certain it is installed in accordance with the
manufacturers instructions and all local codes. A coal stove can perform only as well as its venting system will allow it to.
CAUTION! THE CHIMNEY SELECTED MUST COMPLY WITH THE REQUIREMENTS FOR TYPE HT CHIMNEYS UL 03
DO NOT USE MAKE-SHIFT COMPROMISES DURING INSTALLATION!
3.2 COMMON CHIMNEY PROBLEMS
In order to have a properly operating heating system, the chimney needs to
be capable of providing sufficient draft. The minimum required draft is .06
inches of water column (WC). To measure the draft, drill a hole in the
connector pipe and attach a draft meter. First, check the draft above the
barometric damper (if installed). Then check it below the barometric
damper and make your damper adjustment to where it opens to prevent the
draft from going higher than the .06 in WC. If the chimney is incapable of
supplying the necessary draft, it will need to be improved. Whether it needs
to be raised to a taller height, a flue liner installed, or a different style of cap
placed on the top, the improvement method will need to be determined.
Reasons for insufficient draft:
A) Leaking chimney - Air leaking in around a loose fitting cleanout
door, joints or seams in connector pipe are not secured properly,
cracks or other defects in masonry.
B) Improper chimney height - Chimney does not extend to a
sufficient height above the roof line. (Remember the 3 ft.-2 ft.- 0
ft. rule)
C) Obstructions in the chimney - Make sure the chimney has been cleaned. Different animals have been known to build nests in
chimneys.
-10-
CAUTION! THE CHIMNEY MUST BE A “CLASS A” CHIMNEY IN GOOD WORKING CONDITION. THE USE OF
ALUMINUM “TYPE B” GAS VENT FOR SOLID FUELS IS UNSAFE, AND PROHIBITED BY THE NATIONAL FIRE
PROTECTION AGENCY (NFPA) CODE.
