OUR STORY
We live in the far south of New South Wales and are off the power grid. We began building our rammed earth, pole and straw-bale home at Dignams Creek in 2006. We wanted our home to be ecologically sound. Our heating options were solar power, bottled gas or wood.
With a constant supply of firewood falling down around us, a wood-burning heater was inevitable. But we were not happy with slow combustion heaters. They produce a lot of heat when going, and none the rest of the time. They send most of the heat up the chimney which is a waste and they are prone to creating pollution and deposits. So we spent a long time looking at other options.
While on holiday in Europe we were stranded in a mountain chalet during a blizzard. In the morning they lit a masonry heater. The fire lasted for about one hour. The masonry heater absorbed the warmth and then radiated it all day. We curled up against the heater reading books with damp clothes draped over it to dry. The heat was beautiful, not too hot. We had found what we wanted for our home. Then we researched it further and discovered that they weren’t available in Australia.
With all the experts being half a world away we toyed with trying to design and build our own. We looked at bringing someone out to Australia to build one for us. Then we discovered these kits and included one in our home. It was straightforward to build and we loved the end result.
Our heater met and even exceeded all our expectations – a single burn kept our home warm for 24 hours and we loved learning against it. Friends who visited were equally impressed.
We now knew that masonry heaters were the answer to the problems of the slow-combustion heaters that were getting wood-burning a bad name.
This led us to start Heavenly Heat. We now have highly satisfied customers in across Australia.
EFFICIENCY
Combustion efficiency measures how much of the energy in the wood is converted to heat. The more the better, and the less smoke. Combustion efficiency of our heater has been measured at 95%. There is nothing better than a masonry heater. The average of other wood heaters in Australia is 63%.
Heat transfer efficiency shows how rapidly the heat produced by the fire is transferred to the room. It only measures how quickly the heat is delivered, not the comfort of the room.
A combination of high combustion efficiency and moderate heat transfer efficiency is the ideal in any wood burner. The difference this makes can be seen in the graph which shows more uniform temperature with a masonry heater than with a slow combustion heater.
ENVIRONMENT
Masonry heaters are superior to other forms of wood burners in many respects, but particularly when impact on the environment is being considered. The high combustion temperature ensures maximum burning of the fuel and volatile products given off. As a result, emissions from a masonry heater are lower than any other wood burner. Research in USA shows that emissions for masonry heaters range from 0.5 – 2.0 g/kg.
This is very different to slow-combustion heaters which produce excessive smoke which pollutes the atmosphere and leaves deposits in the flue leading to reduced gas flow and the danger of chimney fires.
Wood burning for heating produces less atmospheric CO2 than using electricity or gas. The use of plantation timber and correct burning can result in a reduction in CO2 levels in the atmosphere (CSIRO. Australian Greenhouse Office). 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". This can be seen in the following graph.
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 does not require this investment and so does not consume resources or energy for this infrastructure.
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, masonry heaters do not suffer the wear and tear inflicted on slow-combustion heaters by the need for constant refueling. They could well outlive some of the houses in which they are installed.
No smoke, just residual heat during a burn.