Load it; light it; leave it; love it!
A full firebox takes about 22kg of hardwood in lengths of up to 450mm. Any good clean hardwood or softwood may be used.
The key to any good fire is dry wood. Moisture in the wood absorbs huge amounts of energy and reduces the efficiency of the fire leading to pollution and waste. Wood should be from trees felled at least two years and then split and dried for a month or more before use. Interior drying storage is best as it can reduce the moisture content to 15% or less. If you cut and split green wood it should be stored in a dry place for TWO YEARS before use.
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Top Down Burning Video This video shows how a top-down fire can raise efficiency and reduce emissions.