Smoke from wood heaters
Harmful smoke pollution can be drastically reduced if we improve the way we use our wood heaters. Here are some tips on how to make a difference:
Check your heater complies with the standard
New heaters are cleaner burning and more efficient than older-style wood heaters and open fires. A slow combustion heater will produce less pollution than a pot-belly stove or open fire because the fire is sealed in an air tight box.
- Check your heater has a compliance plate stating it conforms to the Australian Standard for pollution emissions (AS 4013). If it doesn't you might consider upgrading your heater to a newer more efficient model.
- Use a concentric shroud, venturi cowl or parallel rain excluder to allow the smoke to travel upwards and significantly reduce the amount of rain entering the chimney.
- The top of a chimney should be at least one metre higher than any other building within a 15 metre radius.
Use aged, dry wood
Always burn small pieces of aged, dry hardwood. Green or unseasoned wood contains up to 50% water, which causes fire to smoke.
- When storing wood, stack it under cover in a dry ventilated area. Freshly cut wood needs to be stored for about eight to twelve months.
To check if your wood is dry bang two pieces together. You should hear a loud, hollow crack. Or, tap the wood with a key or coin. Dry wood makes a sharp resonant sound, wet wood makes a dull sound.
- Never burn household rubbish, driftwood or treated or painted wood. It is sure to pollute the air and it can produce poisonous gases.
- Do not burn green pine logs used for constructing garden edges and park and playground equipment. They are treated with copper-chrome-arsenate (CCA) and release toxic substances when burnt.
- Most old painted wood is likely to contain lead-based paint and should not be burnt.
- Never burn coal or coke as they emit sulphur dioxide that can cause health problems.
Use your heater correctly
Always start the fire with small pieces of wood or kindling. Add large pieces of wood gradually when the fire is established.
- Stack wood loosely in your firebox, so plenty of air circulates around it.
- Keep the flame lively and bright.
- Open the air intake and flue for 5 minutes before and 20 minutes after every time you add fuel.
Keep enough air in the fire to maintain a flame. Don't let your heater smoulder overnight.
- To reduce the build-up of soot and creosote, burn the fire fast for 1-2 hours every day the fire is lit.
- Check the flue, chimney and baffle regularly for a build-up of soot or creosote (a tar-like oily deposit.) This build up indicates that the fire is not burning properly, and can cause chimney fires.
- Clean the chimney, flue and baffle at the end of every winter.
Don't let your fire smoulder overnight
In winter, the highest concentrations of fine particles in the air occur after midnight. This suggests that most of fine particle pollution is caused by wood heaters left to smoulder over night.
One of the worse things you can do is to dampen down your fire overnight.
Leaving your heater overnight at the minimum air setting with a full firebox generates very little heat and lots of smoke causing pollution outside and inside your home.
With the air intake closed, the fire is starved of oxygen and cannot burn properly.
Unless your heater is specifically designed for continuous operation (burning bright overnight), let it go out overnight. Rely on your home's insulation to hold in enough heat for the night. Spend money on insulation rather than fuel – it is better for the environment and your health.
If you have a new certified heater designed to burn overnight, follow the manufacturers instructions carefully. Don't cram the firebox full. When the last load is put in, run the heater at maximum for half an hour, then adjust it to the overnight setting.
Consider heating alternatives
Before installing a new heating system you need to ensure your home retains the heat you put into it. Things to consider are:
- Insulating ceilings, walls and floors where possible
- Sealing off draughts
- Effective window coverings
- Zoning living and sleeping areas
- Choosing an appropriate heating system for your home and using it wisely and efficiently.