Choosing the right firewood or pellets to warm your home
By Thomas Chamberland, ISA/TRAQ, MQTW
As Tree Warden, I often get asked about fire wood and wood pellets to heat a home. With winter approaching, I thought this to be a good time to discuss how to choose your fire wood or pellets.
Do you use firewood to heat your home? Here is a list of the types of firewood to burn sorted by high, medium, and low heat value as well as a few important wood-burning tips.
What makes some types of firewood better for burning than others? It comes down to two factors: density and water content. The denser and drier the firewood, the better it will burn and the more heat it can produce. Because of this, hardwoods, which tend to be denser, generally make for better firewood than softwoods. However, softwoods usually burn hotter, and are better if you just need a “quick warm up” of early fall or late into spring vs long steady heat for winter cold.
Highest Firewood Heating Value: 1 cord = 200 to 250 gallons of fuel oil
American beech, Apple, Ironwood, Red oak, Shagbark hickory, Sugar maple, White ash, White oak, and Yellow birch. The most common in the Sturbridge area are the Oaks, Maples and Ash.
Medium Heat Value: 1 cord = 150 to 200 gallons of fuel oil
American elm, Black cherry, Douglas fir, Red maple, Silver maple, Tamarack, and White birch. In this list, Red maple, Elm, and Black Cherry will be the most common.
Low Heat Value: 1 cord = 100 to 150 gallons of fuel oil
Aspen, Cottonwood, Hemlock, Spruce, Red cedar and White pine. Most fire wood dealers do not sell these types of woods, because they burn hot and fast, so unless you are buying for an outdoor boiler, where burning this low value wood does provide the benefit of a fast-hot fire it may be cheap, but plan on frequent trips to the stove to refill.
FIREWOOD BURNING TIPS
How much wood is in a cord?
The cord is the standard measure of volume used for stacked wood. The volume of one cord of wood is 128 cubic feet of stacked wood. Generally, a cord is laid out in stacks that measure 4 feet wide, 4 feet tall, and 8 feet long (4’ x 4’ x 8’) in total. Due to air space between the stacked wood, the volume of solid wood in a cord may be only 70 to 90 cubic feet.
What is a “rick” or “face cord” of wood?
Usually, a cord is made up of a few stacks of wood. One stack of a cord is called a “rick” or a “face cord.” Generally, a rick is 4 feet tall by 8 feet long, and the width of a rick will depend on the length of the individual pieces of firewood. Because of this variability in width, a rick could be equal to ¼ of a cord, ½ a cord, or more.
What is heat value?
Heat value refers to the amount of heat a wood produced when burned. Heat value varies based on the type of wood: A cord of wood with “high heat value” provides the heat equivalent to that produced by burning 200 to 250 gallons of heating oil. Other heat values are listed above.
Freshly cut wood contains up to 50 percent moisture and must be seasoned (dried) to 20 to 25 percent moisture content before burning. Wood containing more than 25 percent moisture is wet, or green, and should never be burned in a fireplace or wood stove. Wet wood is easier to split than dry wood. Wood must be split into pieces and stacked out of the rain for at least six months to season properly.
If steam bubbles and hisses out of the end grain as the firewood heats up on the fire, the wood is wet, or green, and needs to be seasoned longer before burning. Well-seasoned firewood generally has darkened ends with visible cracks or splits. It is relatively lightweight and makes a sharp, distinctive “clink” when two pieces strike each other.
Only buy firewood from local sources. Buying and moving firewood from elsewhere (especially from state to state) is not only frowned upon, it may also be illegal. Transporting firewood from one place to another increases the chance of spreading invasive pests and diseases.
Choosing the right pellets
Wood pellets have been used in the heating industry for years. Different types of wood pellets allow for different experiences and wood pellet stove operation, affecting both the efficiency and running costs of this heating system. There are three main types of wood pellets which include:
Premium wood pellets – These wood pellets contain less than 0.5 percent organic ash content, and generally do not contain bark. They are often made from oak or maple wood species and cost more than lower grades.
Standard wood pellets – This type of wood pellet is most often manufactured from forestry industry waste and contains organic ash content at rates higher than 0.5 percent.
Food-grade wood pellets – Either premium or standard wood pellets can be labeled as food-grade, as long as no additives or binding agents are used in the manufacturing process.
Choosing the Best Product for Your Wood Pellet Stove
Your wood pellet stove will operate at optimum levels with higher quality wood pellets. Shop for products with less than 1 percent organic ash content. Oak pellets naturally have a lower ash content than maple pellets, making them a better choice on average.
Moisture content also makes a difference to wood pellet stove performance. Remember that dry pellets create more heat in the same amount of time. Select lower moisture levels to obtain peak levels of efficiency and the most comfortable levels of heat. Wood pellets, including some standard grade and most premium grade pellets, contain less than 5 percent moisture. Choose a product with no more than 8 percent moisture levels and pay more if necessary. Your wood pellet stove will crank out more heat from each pellet, saving you significant amounts of money over the long term.
The best quality wood pellets have low levels of organic ash content and moisture but come with a higher price tag. Good quality maple and oak wood pellets produce respectable levels of performance from your wood pellet stove, allowing you to maintain a comfortable home all season long. Many pellet stove manufacturers recommend a mix of pellet wood types, with more softwood pellets in the mix providing a hot burn, thus more heat than a hardwood pellet. Remember no matter what pellet you purchase, you have to keep the bags and pellets dry. Wet or moisture swollen pellets will clog your stove feed or not burn cleanly if at all.
Know your pellet stove
Just as in any home appliance there are many pellet stoves to choose from. Shop around and buy one slightly larger than the calculated BTUs burn rate for your home. Once home, take the time to learn the temperature settings, and pellet feed rates for optimal heat production from your stove. The same holds true with pellets, shop around and try different brands. As discussed above, there is a lot to learn. Take the time to learn, and your stove will reward you with many warm years. n
Tom Chamberland is the Tree Warden for the Town of Sturbridge and a Certified Arborist and a Massachusetts Qualified Tree Warden. He enjoys caring for plants that grow in his yard and welcomes reader suggestions for future articles. Email him at: firstname.lastname@example.org