Environment . . .

  • Low emissions
  • High Efficiency
  • Long life
  • No infrastructure requirements
  • No recycling issues
 

Low Emissions

Site-built masonry appliances are specifically excluded from AS/NZS 4013. As they are site built; each one differs. This contrasts with a commercially available ‘metal box’ type heater where they are all the same.
Research in USA shows shows that emissions for masonry heaters range from 0.5 – 2.0 g/kg.  This is less that the limit set in the Australian Standard (2.5g/kg).
The life cycle assessment of greenhouse gas emissions from domestic wood heating conducted by the Department of Environment and Heritage in 2003 showed that greenhouse gas emissions are lower for wood heating than they are for electricity or gas. They concluded that in regard to the minimising of greenhouse gas emissions “firewood is generally more favourable for domestic heating than other sources of domestic heating such as gas and electricity” http://utting.net.au/doc/lifecycle.pdf. This can be seen in the following graph.

efficiency graph

 
Because this graph shows figures for ‘standard wood heaters’ used in Australia, the greenhouse gas emissions from a masonry heater are even lower than those shown.

 

High Efficiency

In August 2015 Australian Standards introduced a requirement for heaters to meet a minimum efficiency level. The level set from 2015 is 55%, which will increase to 60% by 2020.

At the moment, the average operational efficiency for wood heaters in Australia is 65.5%. Masonry heaters typically attain operational efficiency of 80%. Independent laboratory testing of the Tempcast heater in North America demonstrated an operational efficiency of 80% and combustion efficiency of almost 95%. There are no other wood heaters in Australia that reach this level of efficiency.

How to minimise emissions and maximise efficiency

The way you operate your heater will impact the emissions and efficiency. The key things to do are:
  • Burn the fire hot and fast. The faster you can get the fire going the less smoke there will be.
  • Use dry timber and do not burn green wood. The higher the moisture content, the more emissions will be produced and the lower the efficiency.
  • Build your fire as a ‘top down’ fire – the big wood at the bottom and the kindling at the top. This increases the efficiency of the burn.
No smoke, just residual heat during a burn.

No smoke, just residual heat during a burn.

Infrastructure

Almost every form of energy used for home heating, even renewables, require massive investment in infrastructure, for generation and transmission, manufacture and transportation, which adds to further emissions production.

A masonry heater uses wood, our only renewable material, which is not a fossil fuel and, apart from the fuel used for cutting and transporting it, contributes little to the emissions tally.

Recycling

There are masonry heaters in various parts of the world which have been in use for hundreds of years. Although we cannot make any such claims for our heaters, which have been in uneventful use for thirty years, they are made of incredibly durable materials; refractory concrete, brick or stone, cast iron and small amounts of steel, which, should they ever wear out, can be readily re-used or recycled.

In use they do not suffer the wear and tear inflicted on slow-combustion heaters by the need for constant refuelling. They could well outlive some of the houses in which they are installed.