The technology of wood heating The Principles of wood combustion Wood is a complex fuel. It goes through three main phases when it burns. The first phase is drying, when any moisture left in the wood is evaporated. This absorbs energy. Once dry, the increasing temperature causes the wood to undergo chemical change and gas is released from the wood. This is the time when the highest concentration of smoke is produced. If there is a vigorous flame in the wood heater, then this stage of combustion is shortened and most of the smoke is burnt up before it gets to the flue. The second phase of combustion is the main flame burning stage. Burning kindling, or other burning wood, ignites the gases coming off the new wood. The gases burn to give the bright flame we see when wood is burning. The fastest release of gas occurs during the first 20 minutes or so after refuelling a hot heater.
It is essential to have plenty of air to mix with the gas to make sure it burns. This is why it is so important to keep the air control fully open for the first 15 - 20 minutes. Once the wood is well alight, with some burning embers on the wood surface, the chances of the flame disappearing are slight, even when the air is reduced. The main flame combustion phase, which lasts for one to two hours in a typical heater, releases about half the energy in the wood. The third phase of wood burning is the charcoal stage. Once most of the gas has been released from the wood, a residue of almost pure carbon remains. This burns with very little release of smoke. This is when the air supply can be reduced without producing smoke particles. Source: Professor John Todd who has been involved with heater research for more than 30 years
Get the most value from your wood We encourage wood heater owners to take
•
larger logs for slower burning
responsibility of their wood heaters to minimise smoke pollution in the neighbourhood and save money on
Use smaller logs to get the fire established and
•
Stack log ends front to back, not side to side for better air flow
running costs. It is important to remember that smoke is actually wasted fuel that could otherwise have been converted
•
Do not overfill the heater
•
Keep the air controls fully open for the first 20 minutes of operation and again
to heat if the wood had burned more efficiently. Individually, wood heater owners can do a huge amount to reduce the pollution they emit and save
after adding wood •
Add a SmartBurn to increase the woods
money too.
performance by 17%
You can minimise the amount of smoke from a wood
and reduce particle
heater if you;
emissions by up to 54%
•
Burn only dry, seasoned, untreated wood
•
Establish a good fire quickly with plenty of kindling
•
Maintain your heater and flue
Tip You can still use a SmartBurn w ithin a pellet heater, as lo ng as you fin da place to supp ort it flat and level within yo ur burn chamber.
Wood Pellet Heaters Incredibly popular in other parts of the world particularly Europe and North America the uptake of wood pellet heaters in Australia has been minimal relative to the approx. 40,000 new solid wood burning heaters sold annually across Australia. Pellet heaters are appealing 6
for convenience, simplicity and environmental gains, however the availability of an economic pellet supply is often cited as a barrier. Australians overwhelmingly favour their traditional solid wood burning heaters.
More Heat & Less Smoke From Your Wood Fire
