Wood pellet burners

Wood pellet burners look similar to conventional log burners, and are available as both freestanding or fire place insert models. While the efficiencies of wood pellet burners and log burners are similar, pellet burners generally have lower emissions. They also offer you the ability to have a lot more control over how much heat is produced and when.

Unlike log burners, wood pellet burners need electricity to work, so may not be a good choice in areas prone to black-outs.

The pellets used in wood pellet burners are made from 100% wood residues (usually sawdust and wood shavings). These are ground up, compressed into small pellets with the aid of steam and are then dried.

Like wood stoves, many pellet burners may have the option of having a wet-back fitted to heat your hot water.

Wood pellet burners are gaining in popularity in New Zealand, due to their convenience and clean burning properties.

Better heating efficiency

When tested, wood pellet burners have, on average, the same efficiency as log burners. The big difference however is the fuel they use.

The density and, more importantly, the moisture levels of wood pellets are more consistent than those of logs. This means they are more likely to burn with minimal emissions and with a predictable heat output. In comparison, firewood that is damp, or unseasoned/green, often burns poorly and produces lots of sooty smoke.

Better heating control

With a wood pellet burner you can:

• Adjust the rate that pellets are consumed. This gives you control over the amount of heat produced
• Control your room temperature via a thermostat
• Use a timer to automatically switch the unit on and off
• Force more air into the firebox to aid combustion, as most pellet burners have a built-in fan. This effectively blows the hot air out into the room, heating it up quickly and spreading the heat evenly around the room.

This is in direct contrast to wood burners. Typically there is only a small ability to vary either the fuel or air settings with a wood burner. Damping down a log fire to reduce the air intake will slow the fire down, but it also reduces the efficiency of the burn and increases sooty emissions in the smoke produced .

Clean and green

Wood in pellet form is:

• Carbon neutral. All the time trees are growing, they are capturing CO₂ from the air. This CO₂ is released when the wood is burnt, or the tree dies and rots in the forest
• Renewable and sustainable. New Zealand already has large areas of forestry. Generation after generation of trees can be successfully harvested to produce more firewood.

Take action

• For best results, use wood pellet burners that have been tested to AS/NZS 4014.6:2007 standard. Check out the Ministry for the Environment’s list of pellet burners
• Contact your local council to find out more about installing and using a wood pellet burner in your area.

More information

• Consumer's pellet burner free checklist.
• You can find information on wood burner wetbacks from Consumer Online.
• To find out more about wood pellet burners for your home visit the Bioenergy Gateway.