Wood heaters
- Do I need a wood heater?
- Which heater to buy
- What makes a good heater
- Installing your heater
- Lighting a wood heater
- Loading your woodheater
- What you need for efficient burning
- Tips for safe and efficient use
- More information
Wood heaters provide warmth and a pleasant atmosphere. But they are sometimes less efficient than other heating systems and can cause problems if operating badly.
A wood heater that produces a lot of smoke can annoy neighbours and become an environmental and health hazard, particularly in populated urban areas. A badly operating wood heater can also cause indoor air pollution, which could affect your health. So it's important to take care when buying, installing and using a wood heater.
Do I need a wood heater?
Before buying a wood heater, try insulating the room, closing windows and doors, and hanging and drawing heavy curtains. If these options are not right for you, or don't warm your room enough, you will need to think about a better heating system.
You can choose from an electric, oil or gas heater, a reverse-cycle air conditioner, or a wood heater. Think about these different systems and investigate the cost, efficiency and suitability of each one for your rooms. If you're seriously considering buying a wood heater, you might like to consider those that use other solid fuel products (e.g. coal and brickettes) and their related costs.
Which heater to buy
Consider what size heater you need. In Queensland, there's little need for large wood heaters. A heater that is too large for your room will have to be turned down too often, reducing efficiency, creating smoke, and fouling the flue with creosote (a dark, sticky substance that forms when unseasoned wood is burnt). However, one that's too small can result in over-firing, shortening its life.
Always look for heaters with a certificate of compliance from the Australian Home Heating Association or the South Australian Energy Information Centre (also used in Queensland). Wood heaters with these certificates of compliance meet the Australian Standard AS4013 for smoke emissions and AS3869 for design.
What makes a good heater
Choose a heater that requires minimal maintenance and small amounts of fuel to reach the heating level you desire.
Design features that promote complete burning and reduce smoke include:
- properly designed internal baffle plates
- provision for preheating incoming primary air
- features that promote secondary combustion
- insulation of the flue as high up as possible to minimise condensation fouling and assist dispersion and natural draught air flow.
Installing your heater
For your safety, insurance purposes and minimisation of your neighbours' discomfort, ensure your heater is installed according to the manufacturer's instructions by a qualified person or someone accredited by the Australian Home Heating Association.
Make sure the chimney is installed according to relevent Australian standards and the height specifications in your area. A properly installed flue or chimney will:
- prevent smoke or fumes penetrating your neighbours' homes
- disperse smoke
- reduce the concentration of pollutants.
Talk to your local council before having a heater installed. Under building codes, council approval can be required for installation.
Lighting a wood heater
Method 1
- Fully open any dampers or air vents.
- Put a dry log on either side of the firebox, leaving 20-30 cm between the two logs.
- Put in one loosely crumpled page of newspaper.
- Tightly screw up another four or five pages of newspaper and put them on.
- Add some dry kindling and small dry logs.
- Light the fire.
If the wood is dry, you should find this method requires less kindling than other methods, and the fire lights first try every time. Wait 15 minutes or so before adding more logs.
Method 2
The following method is suggested by the Australian and New Zealand Environment and Conservation Council.
- Use firelighters or paper to light the fire, then add large pieces of wood after a bed of coals has been established.
- Rather than lighting one central fire, build smaller fires regularly, providing plenty of air.
- Each time fuel is added, open the air controls and add wood. The controls can be turned down to give a comfortable fire after 10-20 minutes, when the fire is burning properly.
- The control should be left fully open for 30 minutes, as a hot fire will heat the stove quickly and burn the wood completely and cleanly.
- Keep the fire burning at a moderate rate, not allowing it to smoulder.
Loading your woodheater
- Leave about 2.5 cm between logs when loading them onto the fire—this allows combustion air to flow between the logs, developing hot pockets of glowing coals.
- If your heater does not have a grate, place the logs so that their ends are facing the incoming stream of air. Logs laid the other way stop air getting to the base of the fire, creating more smoke and less heat.
- Burn at high temperatures to minimise chimney fires, which are caused by the burning of creosote that has lodged on the walls of the flue.
What you need for efficient burning
For a wood heater to operate efficiently, the wood inside must be burnt completely. This reduces fuel expenses and minimises environmental and health problems. For wood to burn completely, you will need sufficient:
- air flow to provide oxygen for combustion
- heat for combustion
- mixing of air and hot combustion gases to promote complete burning
- time to allow complete burning.
Unless all these factors are present in sufficient quantities, incomplete burning will result, producing lots of smoke, soot and chemicals.
Efficiency will increase if you close doors, windows and curtains (especially if you have heavy curtains) to keep heat in the room. Make sure you still let some air flow into the room.
What not to burn
- wood treated with copper-chrome-arsenate (the green colour in playground logs), which will release poisonous fumes
- wood from the seaside, which contains corrosive salts that may damage your heater
- garbage, which may contain plastics and other materials that will release harmful fumes, and organic substances that may burn poorly (try to minimise your garbage and recycle as much as possible)
- painted timber, which will release poisonous fumes
- particle board, which contains chemicals that will also release harmful fumes.
Most importantly, never use petrol, oil or kerosene to help light a fire—they may cause an explosion. Burn only fuels recommended by the manufacturer or designed for use in the heater.
Tips for safe and efficient use
- Read the manufacturer's instructions.
- Buy the fuel recommended by the manufacturer.
- Order firewood early from a reputable fuel merchant—burn dry, well-seasoned wood.
- Always have some fresh air flowing into the room in which your heater is located to provide air for combustion.
- Always consider your neighbours and create as little smoke as possible.
- Light and burn your fire efficiently, minimising the smoke released from your chimney—the less smoke, the cleaner and hotter your fire is.
- Never leave the house when the fire is burning.
- Season wood properly before use by storing it for six to eight months.
- Store wood off the ground in a criss-cross stack to allow the air to circulate freely. Keep it dry.
Your fire is burning completely if coals are glowing brightly and there are bright swirling flames. This means you have enough heat, air and mixing of coals. If the fuel is dark, smouldering, barely alight and producing a lot of smoke, the fire is burning incompletely.
More information
Australian Home Heating Association Inc.
National Office
First floor
7 South Road
Brighton VIC 3186
Ph: (03) 9592 2522
Fax (03) 9592 8080
Email Home Heat
Last updated: 22 November 2006