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Have you heard of wood pellets and the heaters that burn them?

This technology is commonplace in Europe and North America where they are used for domestic heating.

Wood pellets are most commonly manufactured from waste wood that is a byproduct from another processing operation.

Often the waste is sawdust or wood shavings. The pellet is made by extruding the material through a die where the high pressure from the extrusion process creates heat that binds the wood material together to form the pellet.

The wood pellets are burnt in pellet heaters or pellet stoves.

The pellet heater is about the same size as a Coonara type of heater.

The pellets are placed in a hopper and upon ignition, which is simply turning on a switch, an auger in the bottom of the hopper feeds a measured amount of wood pellets into the burn pot.

An electric element at the back of the burn pot heats up and as it does so, a fan blows air over the element and onto the pellets.

Eventually this super-hot air causes the pellets to ignite and begin to burn.

As the pellets burn and the exhaust gases heat up, the heat from the exhaust triggers the auger to begin to operate.

The auger delivers measured amounts of pellets into the burn pot, and depending on the heat requirement setting, more or less pellets can be delivered creating variable heat output.

A second fan in the heater then draws air from the room, circulates it within the heater and then exhausts the heated air back into the room.

Because of the efficiency of the combustion process, the only visible smoke is at start-up and the resulting emissions are very low. 

So, what are the advantages of wood pellet heaters?

Firstly, operation is as simple as turning a switch; however there is a requirement to ensure the pellet hopper is replenished and the unit is kept clean.

There is also a degree of skill required to keep the air mix correctly adjusted, which comes with operational experience.

Secondly, as the wood pellet heater burns pellets efficiently, and its heat output is easily controlled, the overall quantity of wood biomass burnt annually is reduced.

Some claim the annual requirement for wood pellets can be as little as one tonne a year, however this is likely to be a situation where the house is typically vacant during the day and the unit is operated for a few hours during the evening and the morning.

Keep an eye out for this product because if the overseas trend is a guide, we will soon be adopting this technology.