When heating with wood in fireplaces is recommended to observe several principles.  We are making fire only with:

1. hard and non impregnate wood (oak, beech, birch) and
2. dry wood.

Fireplace wood shoul buy 2 years gamey and dried. Then the from 15 to 20% humidity. We store it saw up (the length from 30 to 40 cm) and chopped and  covered with in shelters in open air (outdoors) with a sufficient air supply. Ensure with it that the wood not damped and finished the drying before use. Advice: buy the wood for the fireplace and store it for at least 1 year prior to its use.

The ideal moisture content of wood is around 20%. There are several ways to determine if wood is dryed out. When cakes 2 pieces of wood of yourself you should hear the wood "sings". You can also wrap the wood in plastic bag in warm room - if the bag inside steamed up , the wood is not sufficiently dryied out. A good indication of dry wood are cracks. The simplest and more accurate way is to check moisture content of wood with hygrometer - ask your dealer or ask your chimney consultant.

Remember you that failure to take these principles will not only reduce the performance of the fireplace, causing problems with heating  (fumigation facilities, poor chimney draft, does not want to burn wood), but in particular is causing considerable pollution not only chimney, but mostly the fireplace.