Vermont Casting 2477 - Manual (Page 29)

29
Dutchwest Non-Catalytic Convection Heater
30002314
Single Venting
Your stove requires a dedicated flue. Do not connect the
stove to a flue used by any other appliance. Chimney
draft is a natural form of energy and follows the path of
least resistance. If the stove is vented to a flue that also
serves an open fireplace or another appliance, the draft
will also pull air in through those avenues.
The additional air flow will lower flue temperatures,
reduce draft strength and promote creosote development;
overall stove performance will suffer. The effect is similar
to that of a vacuum cleaner with a hole in the hose. In
some extreme instances, the other appliance can even
impose a negative draft and result in a dangerous draft
reversal.
Fuel
Even the best stove installation will not perform well with
poor fuel. If available, always use hardwood that has
been air-dried (“seasoned”) 12-18 months. Softwood
burns more rapidly than hardwood and has a high pitch
content that can result in creosote. Decayed wood of any
type has little heat value and should not be used.
Unseasoned (‘green’) wood has a high moisture content.
Much of its heat value will be used to evaporate moisture
before the wood can burn. This significantly reduces the
amount of energy available to warm your home, as well
as the intensity of the fire and temperature of the exhaust
gas. Incomplete combustion and cool flue temperatures
promote creosote formation and weak draft.
You can judge the moisture content of wood by its ap-
pearance and weight or use a commercially available
moisture meter for an exact measurement. Unseasoned
wood will be a third heavier than dry wood. Also, look for
cracks (“checking”) in the ends of the log that result from
contraction as the wood dries. The longer and wider the
cracks are, the dryer the wood is.
Creosote
Creosote is a by-product of low-temperature stove op-
eration, weak draft, or both. It is a tar that results when
unburned gases condense inside the flue system at tem-
peratures below 290˚ F. Creosote is volatile and can gen-
erate a chimney fire. All of the installation characteristics
that adversely affect chimney draft also promote creosote
condensation. Consequently, you can minimize creosote
accumulation with an effective chimney design and the
use of operational techniques that encourage good draft
and complete combustion.
Inspect your chimney frequently and clean it whenever
accumulation exceeds 1/4”.
Backpuffing
Backpuffing is a condition that results when the draft is
too weak to pull flue gases out of the chimney system as
fast as the fire generates them. Volatile gases build up
within the firebox until reaching a density and temperature
at which they ignite. With this ignition, you may hear a
muffled popping sound and see a bit of smoke forced out
of the stove.
This condition is most likely to occur in the Spring or Fall
when moderate outdoor temperatures and low intensity
fires produce weak draft. If your stove back-puffs, open
the damper to let the smoke rise to the flue more quickly.
Also, open the air inlets to induce a livelier fire and speed
airflow through the stove. Avoid large loads of firewood at
one time. You should always see lively, dancing flames in
the firebox; a lazy, smoky fire is inefficient and will pro-
mote draft problems.
Draft Testing
An easy way to determine whether your chimney draft is
strong enough is to close the stove damper, wait a few
minutes to let the airflow stabilize, and then test whether
you can vary the strength of the fire by swinging the air
control open and closed. Results here are not 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 is no
change, the draft is not yet strong enough to let you close
the damper. You will need to open it for a while longer and
manage the fire with the air inlet until the draft strength-
ens.
Keep a record of your operating habits and relate them to
their effects on the stove’s function. You’ll be rewarded
with safe and efficient performance.
Negative Pressure
Good draft also depends on a sufficient supply of air to
the stove. The chimney can’t pull in more air than is avail-
able to it. Sluggish draft can be caused by a house that is
tight enough to prevent the ready flow of air to the stove,
or by competition between the stove and other appliances
that vent indoor air to the outside; i.e., exhaust fans for
range hoods, clothes dryers, bathroom fans, etc.
If the chimney draws well when all such equipment is
turned off (or sealed, in the case of fireplaces and/or other
stoves), you need to be attentive in timing the use of the
other appliances. If you need to crack a nearby window
or door to enable the chimney to pull well, you should
install an outside-air intake to bring combustion air into
the room.
Conclusion
Woodburning is more an art than a science. Art includes
technique; and since installations, homes, and fuel vary,
the stove operator must also vary technique, (mostly
timing), to achieve satisfying results. Over time, you will
become familiar with the features of your particular instal-
lation; you will be able to identify cause and effect in a va-
riety of seasonal circumstances, and adapt your operating
habits to changing conditions.