Vermont Castings Intrepid II Installation & Operating Manual page 28

Fuel:
Even the best stove installation will not perform well with
poor fuel. The best fuel is hardwood that has air-dried 12-
18 months. Softwood burns, but not as long as hardwood.
Fairly 'green' wood has a good amount of moisture in it; it
will burn, but some of the heat potential is used to drive the
remaining moisture off the wood. This reduces the amount
that reaches your home and can contribute to a creosote
problem. There are moisture meters available for firewood;
you can also judge your wood by its appearance and weight.
If you get it green, lift a piece and get a sense of its weight;
it can lose a third or more of its weight as it dries. Also look
at the ends of a log; as it dries it shrinks and often cracks.
The more weathered and cracked a piece is, the drier it is.
Dry wood burns readily with a good chimney draft. But with
modern stoves, especially catalytic ones, the wood can be
too dry. While extra-dry wood has little creosote in it, the
remainder can 'gas out' from the wood quickly and densely
enough to overload the catalytic burner. If you hear a rumbling
or roaring noise, like a propane torch, from the stove, that is a
sign that the catalyst is seriously overfiring. The catalyst is a
platinum film on a ceramic base; the metal can get to higher
temperatures than the ceramic can take, and overfiring the
catalyst can break it. Dry wood can also burn out faster than
you want. If your dry wood burns out too quickly or overloads
the catalyst you can mix in greener wood to slow the fire down.
Back-puffing:
Back-puffing results when the fire produces volatile gases
faster than the chimney draft pulls them out of the firebox.
The gases back up in the firebox till they're dense enough
and hot enough to ignite. If your stove back-puffs, you should
open up the damper to let the smoke rise to the flue more
quickly, let more air into the firebox, and avoid big loads of
firewood. Run your stove with enough primary air so that
you always see lively, dancing flames in the firebox; a lazy,
smoky fire is inefficient and can contribute to creosote buildup
in the chimney.
Draft Testing:
An easy way to test your chimney draft is to close the stove's
damper, wait a few minutes to let the airflow stabilize, then see
whether you can vary the strength of the fire by swinging the
air control open and closed. Results are not always instant;
you may need to wait a few minutes for a change in the
air control setting to have an effect on the fire. If there's no
change, then the draft isn't strong enough yet to let you close
the damper, and you'll need to open it for a while longer and
manage the fire with the air inlet until the draft strengthens.
If you keep track of your burning habits and relate them to
their effects on the stove's operation, you'll be rewarded with
good performance and a safe system.
28 Vermont Castings • Intrepid II Installation & Operating Manual_R48 • 11/17
Negative Pressure:
Good draft also depends on a supply of air to the stove; a
chimney can't pull in more air than is available to it. Sluggish
draft results when a house is tight enough to prevent the
ready flow of air to the stove, or by competition between the
stove and other equipment that sends indoor air outside -
especially power-driven equipment like range hoods, clothes
dryers, etc. If the chimney draws well with all other equipment
turned off (or sealed, in the case of fireplaces and/or other
stoves), then you simply need to be careful with timing the
use of the other equipment. If you need to crack a nearby
window or door to enable the chimney to draw well, that's
a sign that you should install an outside-air intake to bring
combustion air directly to the stove. Vermont Castings dealers
carry adapters to attach to the stove to connect an air duct
for outdoor combustion air.
Conclusion:
Wood-burning is an art rather than a science. Once the stove
and chimney system are in place, the stove user can only
vary technique, mostly your timing, to achieve good results.
If you keep track of your burning habits and relate them to
their effects on the stove's operation, you'll be rewarded with
good performance and a safe system.
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