Well chosen and properly stored firewood can produce a clean, bright flame that will enhance your home without polluting your air. Select seasoned firewood and store it in a safe, dry place.
Green firewood-firewood that has been recently cut-is not suitable for burning. It contains up to 45% water, far more than is desirable to produce a clean, smokeless burn. Burning green wood involves removing the water as well as setting fire to the wood. The heat produced by the fire must first dry the wood out, then get on with the process of combustion.
Seasoning the firewood will give you a head start on the process of removing the water from the wood. The sun and the air do some of the job for free. They won't do the whole job. Even seasoned wood has a 20-25% moisture content. But that's sufficiently dry for a good clean burn. Wood that's been cut at least 6 months in advance and stored in a dry place is ideal for your fireplace needs.
Look for wood that has darkened ends and visible splits or cracks. Pick it up and test the weight. It should seem a bit light compared to a comparable fresh cut log. Green wood will look fresher and be heavier. Smack a couple of the pieces together and listen to find if it makes more of a clap or crack (good) or a dull thud (bad).
Even these cues can fool you, though. Buy from a reputable seller who's been around for a while. Or buy green wood at least 6 months in advance and season it yourself.
Firewood can't just be left outside at the mercy of the elements. A few good rains can cause seasoned firewood to regain all of the moisture it has lost. Snow, followed by thaw, can be even more effective as the slowly melting water has a chance to seep in. Water from the wet ground can leach up into the wood from beneath. Store the wood off the ground if possible.
However, if you're seasoning the wood yourself, you don't want to store it inside. Sun and wind are important parts of the seasoning process. A wood shed is an ideal solution. A wood shed has a roof but well-ventilated sides that allow for plenty of air flow and angled sunlight.
With a little more effort, a simple woodpile can be made to do the trick. Store it off the ground if possible and cover it with a tarp at the first sign of rain or snow. Remember to remove the covering when the weather turns sunny again, especially if you can't store the pile off the ground. You don't want the underlying ground to become a moisture trap.
Don't burn wood that has been treated or painted, especially wood from decks or landscaping ties. The fire can release toxic chemicals such as arsenic into your home.
A small amount of pine is ok and can be used as kindling. But don't burn large quantities of pine or other resinous softwoods. The fires can quickly get out of control. This is especially true of your Christmas tree, a large piece of tinder that's been drying for weeks and can go up in a startling, dangerous flash.