Good Burning Practices
Most heating contractors will size the heating appliance (fuel oil, propane, natural gas, etc.)
with the intention to heat your building on the coldest days of the year for your area.
The problem arises that there are approximately eight of these days in a year, that means that
your heating appliance is over sized and inefficient for the better part of the year.
Of course the heating contractor knows you don't want to be cold on those days so they size
your heating appliance to provide the required heat for those coldest days.
If you use an alternative heating appliance in addition to conventional heat sources,
undersize it a bit and it will be much more efficient for more days of the season.
An oversized alternative heating appliance will satisfy your heating needs too quickly, shut
down and produce lots of smoke and creosote, unless you properly control the combustion
by limiting the amount of fuel you put into the wood heating appliance.
Smoke burns @ 1100 degrees Fahrenheit, so if your appliance is shut down and smouldering
it is not going to create a hot enough fire to burn the smoke. This is a typical example of the
horror stories out there of the irresponsible next door neighbour who has an alternative heating
appliance that is way oversized an does not practice good burning practices.
By under sizing your alternative heating appliance you will have a burning fire for more of the
time, not a smouldering one, making your appliance more efficient! Your conventional heating
appliance would be required to make up the difference on those extreme weather days.
Load your alternative heating appliance as often as is possible, as the smaller the fire the
more it will actually be burning instead of smouldering, which means hotter fire, less ash,
less smoke and better efficiency.
Based on the current weather conditions, your anticipated heating demand and a little
experience at operating your alternative heating appliance you will be able to determine how
much fuel that you will have to load into the firebox so that it will have enough to burn
in a given time frame with out the fire actually going out.
Check the adjustment of the combustion air damper and adjust if necessary for a clean
efficient burn every time there is a change in the quality of wood you are burning, so
that the wood burns completely.
Burn only what the alternative heating appliance was designed to burn.
i.e. - If it is a wood burner do not burn gas, oil, tires, "treated" wood, plastics, etc.
Most forced draft fan outdoor boilers will burn un-split seasoned logs (the wood does not
have to be split to be seasoned). The larger pieces burn more efficiently than smaller ones,
as they tend to burn slower, hotter and more completely.
If wood burns to fast, whether it be because of the fact that it is to dry
(less then 20% moisture content), or is a softwood (a species that burns faster),
the heating appliance is not be able to capture the heat as fast as it is being produced,
so excess heat is exhausted out the chimney resulting in less efficiency.
Wood that is too wet (greater then 30% moisture content), just does not burn very well,
as the first heat output generated by the wood has to evaporate the excess moisture,
whichresults in a colder burn, hence more creosote, more smoke and cannot actually
be expected to burn efficiently.
This effectively could reduce the wood burning appliance's rated Btu output up to 50%
depending on type of fuel being burned. (i.e. dry or wet white poplar)
Store your wood so that is not exposed to the elements and let it season to a 20% to 30%
moisture content range. Wood with this moisture content burns slow enough to burn more
completely resulting in more heat output and with minimal smoke.
By following the above practices "most" alternative heating appliances will burn without
producing smoke. The exceptions are products of poor design & almost all outdoor
alternative heating appliances that rely on natural draft to create combustion.