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Chimney Installation
CHIMNEY
Your wood furnace may be hooked up with a factory built
or masonry chimney, matching the diameter of the exhaust.
If you are using a factory built chimney, it must comply with
UL 103 or CSA-B365 standard; therefore it must be a Type HT
(2100°F). It is extremely important that it be installed according
to the manufacturer’s specifications.
If you are using a masonry chimney, it is important that it be
built in compliance with the specifications of the National
Building Code. It must be lined with fire clay bricks, metal or
clay tiles sealed together with fire cement. (Round flues are
the most efficient).
The interior diameter of the chimney flue must be 6”. A flue which is too small may cause draft problems, while a
large flue favors rapid cooling of the gas, and hence the build-up of creosote and the risk of chimney fires. Note
that it is the chimney and not the furnace which creates the draft effect; your furnace’s performance is directly
dependent on an adequate draft from your chimney.
Do not connect this unit to a chimney flue serving another appliance.
The following recommendations may be useful for the installation of your chimney:
•
It must rise above the roof at least 3’ (0.9m) from the uppermost point of contact.
•
The exterior portion should be double or triple wall pipe to ensure proper draft.
•
The chimney must exceed any part of the building or other obstruction within a 10’ (3.04m) distance by a
height of 2’ (0.6m).
•
Installation of an interior chimney is always preferable to an exterior chimney. The interior chimney will be
hotter than an exterior chimney that is being cooled by the ambient air outside the house. Therefore the gas
which circulates will cool slower, thus reducing the build-up of creosote and the risk of chimney fires.
•
The draft caused by the tendency for hot air to rise will be increased with an interior chimney.
•
Using a fire screen at the extremity of the chimney
requires regular inspection in order to insure that it is
not obstructed thus blocking the draft, and it should be
cleaned when used regularly.
IMPORTANCE OF PROPER DRAFT
Draft is the force which moves air from the appliance up
through the chimney. The amount of draft in your chimney
depends on the length of the chimney, local geography,
nearby obstructions and other factors. Too much draft
may cause excessive temperatures in the appliance.
Inadequate draft may cause back puffing into the room
and ‘plugging’ of the chimney. Inadequate draft will
cause the appliance to leak smoke into the room through
appliance and chimney connector joints.
An uncontrollable burn or excessive temperature indicates
excessive draft.
Take into account the chimney’s location to insure it is
not too close to
neighbors
or in a valley which may cause
unhealthy or nuisance conditions.
MASONRY CHIMNEY
Ensure that a masonry chimney meets the minimum
standards of the National Fire Protection Association (NFPA)
by having it inspected by a professional. Make sure there are
no cracks, loose mortar or other signs of deterioration and
blockage. Have the chimney cleaned before the furnace
is installed and operated. When connecting the furnace
through a combustible wall to a masonry chimney, special
methods are needed as explained in the “Combustible
Wall Chimney Connector Pass-Throughs” Section.
