You can use slow combustion wood burning heaters providing they do not smoke excessively. However, wood heaters are a major source of air pollution, so use them wisely.
Open fireplaces are very inefficient so their use is discouraged. Their heating efficiency is only about 10% as air flow causes most heat generated to go up the chimney. This means they require considerably more fuel, which in turn causes greater pollution.
Using a woodheater or open fireplace
Improving your slow combustion heating
Reducing wood smoke (PDF 395KB)
Requirements
Each council has its own rules for installing open fireplaces and wood heaters, so check with your local council about its requirements.
Reducing pollution
You can drastically reduce this pollution by improving the way you use your wood heater.
Do not allow fires to smoulder overnight as that causes the greatest increase in pollution.
To avoid problems, the air intake of any wood heater should be kept high enough to maintain a flame at all times while it is in use.