Research has shown that wood stoves create fine particulate matter which vented into the atmosphere through your chimney can become a health hazard for your neighbourhood. This polluting effect can be minimised by following certain guidelines, which fortunately happen to be a good idea also because they save you money. It all hinges round burning the wood at a high enough temperature to ensure maximum combustion and efficiency.
First, if you have an old wood burning stove, its efficiency may be 60% or less. That's the amount of heat you are getting into your room or house, compared to the total heat produced, the rest being lost up the chimney. Doesn't sound too good does it, but it's at least two or three times more efficient than an open hearth fire! Even so, it's better to replace the old with a modern stove that will give you up to 85% heat output. Is it possible stoves will get even more efficient in future? Unfortunately not, because 85% is close to the maximum allowed by the laws of physics. If the stove is too efficient, that will mean no hot air is going up the chimney, which means zero airflow is being created to burn the wood, so the efficiency falls back down again. It is this opposition between the need to limit hot air loss, and the need to still be venting sufficient hot air to drive the fire, that limits the maximum efficiency obtainable.
Second, make sure the wood is dry, 20% moisture content or less. How will you know that? Purchase kiln-dried wood from a reputable supplier. Don't be fooled by con artists offering extra cheap wood, not kiln dried. It won't burn hot, so utimately you will be losing money. If it's wood you have cut down yourself from your garden, leave it to dry out for at least a year under cover. And purchase a moisture meter for wood. This is an electronic gadget with two sharp prongs which you press into the wood to get a reading. For example, some garden wood this writer cut down registered 46% moisture but after six months drying out was already down to 20% and ready for burning.
Third, burn your fire hot. Get a magnetic stove thermometer, which has a face like a clock dial. It attaches to the flue or to the stove top near the flue. A needle moves as the fire heats up. You want the needle to stay within a central marked-out band of maximum efficiency, so ensure the stove is kept within it. This may require adding extra fuel, or adjusting the draught lever for increased or diminshed incoming air.
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