Published: October 22, 2009 06:45 pm      

Don’t get burned when buying firewood

EDMOND — The day the firewood gets delivered at my house is almost as magical as Christmas morning. There is nothing as relaxing as coming home in the dead of winter to sit in front of the fire. I look forward to this all year. Some may think that a person who sits on the hearth until her back just can’t take the heat anymore is crazy, but I suppose most gardeners are.

Aside from the sheer recreational enjoyment, burning firewood can have some economic benefits if the proper system is in place. Unfortunately, many homes have an open fireplace. This system often removes more heat from a house than it puts back because a fire will create an open draft that will suck the heat out of an area and send it right up the chimney.

An efficient air-tight wood stove, on the other hand, can achieve an efficiency of up to 70 percent fuel input to actual heat output. The efficiency of a stove is affected by the design and location of the system, as well as by indoor and outdoor temperatures and individual use patterns. Most fireplaces that I’ve seen recently are more concerned about aesthetics than efficiency.

Even though the fireplace dealt may not be the most efficient, there is the opportunity to increase the heat produced by selecting the best type of firewood. Different types of wood will yield varying amounts of heat when burned. Wood goes through different stages when it burns. Heating efficiency of firewood depends on how that wood progresses through three stages. Energy is expended in each of the three stages.

In the first stage, wood is heated to a point where the moisture within the wood cells can evaporate. After the wood has dried, it then undergoes a chemical breakdown to charcoal, volatile gases and volatile liquids. The second stage is indicated by the obvious visual sign of actual flames. What burns in this second state are the volatile gases and volatile liquids. Finally, the third stage occurs when the charcoal burns and can be seen when the embers glow. During this third stage heat is radiated from the burning charcoal. This also is known as the “aaahhhhh” moment when sitting in front of the fireplace.

Different species of wood burn and expend energy differently throughout these three stages. Good firewood: (1) is dry, (2) burns through the second stage evenly, without sparks, and with a minimum of smoke production, and (3) spends a long time burning in the third phase i.e. has good “coaling qualities.” To view a table that describes and categorizes the burning qualities of various species visit www.osufacts.okstate.edu and type “firewood” into the search engine. This will direct you to fact sheet NREM-9440 “Firewood: How to obtain, measure, season and burn.”

A good place to start when looking to purchase firewood is to ask friends who have already found a reliable source. If that isn’t any help, the next step is to the trusty phone book. Companies can be found under firewood or tree services. To help with the lingo when purchasing firewood there is some background information that you might find helpful.

There are several terms that can be used to describe a given amount of firewood. It is important that the buyer and the seller both be on the same page when it comes to describing an amount of firewood. The State of Oklahoma has developed regulations for the sale of fireplace and stove wood. “Wood … for use as fuel shall be advertised, offered for sale and sold only by measure, using the term ‘cord’ and fractional parts of a cord, or the cubic meter.” So what the heck is a cord? A cord is a standard measure of wood that stands 8 feet long, 4 feet high and 4 feet wide.

Another term worth mentioning because it seems to be commonly used, but not recognized by Oklahoma law, is a “rick.” A rick is a non-standardized unit of measure that refers to a stack of wood 8 feet long, 4 feet high and the width of a single stick of firewood. Though amounts of actual wood are going to vary on the way the wood was split and the skill of the stacker typically a rick will equal between one-third to one-half the amount of a standard cord.

Who knew there was so much to burning firewood? For more reading, look up the fact sheet online or contact your local OSU County Extension Office, and they’ll be happy to mail it to you. You might even enjoy reading it while sitting in front of a toasty, stage-three fire.



SAMANTHA SNYDER is a horticulture educator for the Oklahoma County OSU Cooperative Extension Service.