Are you wondering whether it really matters what type of wood you use in your fireplace or wood-burning stove? Is there a difference between firewood?
Actually, there is. The most important reason has to do with how much the type of wood contributes to creosote build-up. When you burn wood in your fireplace or in the wood stove, the smoke created begins to travel up the chimney. As it travels upward, the smoke starts to cool down and condense. The condensation leads to smoke particles developing within the chimney walls known as creosote, which is extremely flammable. Also, some woods tend to produce more byproducts of combustion including soot and a variety of compounds that you don’t want to release into your home.
First of all, you need to make sure you let your wood completely dry. Ideally, you should let it dry or “season” for at least 6 months after it is cut—actually a year or more is highly recommended. The reason is, wet or “green” wood produces a greater amount of particles that tends to smoke more. All firewood contains water but freshly cut wood can contain up to 45% of water while seasoned firewood has about 25% moisture content. Also, well-seasoned firewood is easier to start, produces more heat, and burns cleaner. If you burn green wood, the heat produced by combustion must dry the wood before it will burn, using up a large percentage of the available energy in the process. The result is less heat to your home and literally gallons of acidic water within your chimney. Keep in mind, well seasoned wood will appear grayish in color on the outside, appear cracked and darker on the ends, seem relatively lightweight, look white inside when split in half, and will make a clear “clunk” sound when two pieces are knocked together.
However, even seasoned wood can be bad. If stored improperly, the wood can become ruined by constant rain or snow coverage that allows the wood to absorb large amounts of water—making it unfit for burning. Wood for your fireplace or wood-burning stove should be stored off the ground to protect from excess moisture. An ideal situation is a wood shed with plenty of air circulation to promote drying.
Finally, all firewood is not created equal and it is important to use the right type of wood for your fireplace or wood-burning stove. The best wood to use is one that burns clean and smooth. As a general rule, hardwoods are the better choice, such as hard maple, oak and ash because they tend to burn hotter and therefore, produce less residue. In addition, you should never use treated or painted wood in your stove or fireplace because it gives off chemical compounds when burned that can release dangerous amounts of arsenic and other toxic compounds in your house.
The following is a quick list of firewood types with their specific burning qualities and recommendation for fireplace use.
Oak is a hardwood and considered one of the best species for firewood use. When dried properly, it can produce a very slow-burning fire with lots of heat. Oak is difficult to ignite but will enjoy the rewards once it is burning with intensity.
Hard Maple is extremely dense and heavy which allows the wood to burn very slow and even compared to other hardwoods like oak and hickory.
Ash is also highly recommended because it produces a steady flame with good heat output.
Birch is attractive and produces good heat output but it does burn fairly quickly. While it can be cheaper than other species, you’ll go through it faster so it is best to mix in with other types.
Cedar is a good burning wood that produces a consistent and long heat output but with a small flame. However, it does tend to crackly and spit with the sap causing deposits to form in the flue after prolonged use.
Pine is a readily available softwood that seasons faster than hardwood varieties, is easy to split and easy to start. However, it burns very quickly and does not produce the heat of hardwoods. Burning pine is usually characterized by exploding sap pockets that cause sparking. This can be attractive yet can cause creosote buildup in your chimney. Many use this wood to start the fire but switch to hardwoods once the fire is hot.
Fir is probably the best conifer for firewood and produces a moderate amount of sparking. Douglas Fir has a medium heating value and does not produce too much ash.