The Fine Art of Woodburning:
Principles to Learn
By Karen Lamansky
Lindemann Chimney Supply
You're probably thinking: There's
a fine art to woodburning?" You bet
there is!
There are similar principles to every
art. There are preparation, materials,
techniques, maintenance of tools and
clean-up. However, woodburning takes
it one step further. Successful clean
burning is dependent upon draft which is
in turn dependent upon many factors.
Draft
Draft, in regard to woodburning,
is the force of the column of air in the
vent/heating system that is driven by the
air temperature difference between the
inside and the outside air. For instance,
if you tried to start a fire on a 60 degree
day and it was 68 in your home, there
would be minimal draft (only eight degrees temperature difference)
and this may cause the woodstove/fireplace to smoke into the
room.
On the other hand, if you try to start a fire in a fireplace along
the outside wall of the home, the air inside the firebox will likely be
colder than the room air. There could also be cold air being drawn
into the house through that firebox. Remember the principle: Warm
air rises, cold air falls. A fireplace in this situation needs to be prewarmed to establish the correct flow of the flue gases. The same
problem can happen with a woodstove where the chimney/chimney
pipe is run along the outside of the home.
For woodstoves, there's an easy solution. A product has been
developed to preheat the flue and is as easy to operate as using a
remote control.
Otherwise, there are always the old standbys that heat up the
firebox pretty quickly:
• Using kindling and paper in the firebox.
• Using a wax starter brick that creates minimal smoke.
• Installing a chimney exhaust fan.
• Using a hair dryer to pre-warm the flue.
Another important consideration is the flue to fireplace/woodstove ratio. If the flue is too large, it can cause the flue gases to
move more slowly through the vent, cooling as they go. On the
other hand, a flue that's too small restricts
the amount of air flow drawn into the appliance, affecting how the appliance performs
and vents.
If the woodstove/fireplace has restricted draft because the damper is not set correctly, the appliance or fireplace won't burn
effectively. The damper should always
be fully opened upon starting the fire, and
in the case of fireplaces, it should be left
open until the fire is completely out. Once
a woodstove heats up and coals are established, it can usually be damped down
to an optimal setting. However, some
conditions can affect these settings. If it's
really windy, it may burn with wildly dancing flames and may need to be damped
down more than usual.
There needs to be a correct balance
of heat, oxygen and fuel to achieve a clean, effective burn. Too
much fuel and too little oxygen lower the heat and result in lower
appliance and flue temperatures. Never try to achieve a long burn/
overnight burn by stuffing a lot of wood in the stove and then damping it completely down. This causes excessive creosote build-up
and could result in major expenses for chimney cleaning or repair.
Fuel Load
One of the best ways to load a woodstove is what my father
taught me. Put two medium sized logs in the firebox with a couple
of inches between them. Add smaller logs over those logs in a
crisscross fashion with kindling at the top (I use part of a wax starter
brick or fire starter).
The kindling or starter at the top helps to quickly heat the flue.
As the smaller top logs start to burn they drop coals down which in
turn ignite the larger logs at the bottom. Leaving the gap between
the two bottom logs is crucial to creating sufficient oxygen flow and
turbulence for an effective burn.
These are some of the principles behind the fine art of woodburning. This knowledge was second nature to older generations
who grew up heating and cooking with wood. As we move towards
more independence from fossil fuels and turn towards renewable
resources, the art of woodburning will become second nature for us
to pass down to younger generations.
Reprinted, with permission, from the September 2010 issue of The Chimney Sweep News,
an independent trade magazine for chimney service professionals. Jim Gillam, editor/publisher. 541-882-5196. www.ChimneySweepNews.com