WHAT IS "SEASONED" WOOD?
(And Why Does It Matter?)
WHAT DOES THE WOODSTOVE INDUSTRY SAY?
What the woodstove industry means when a woodstove manual states that you should only burn “seasoned” wood is often quite different than what a local woodcutter means when he speaks about “seasoned” wood. In a nutshell, the industry means firewood which has been dried (cured) for at least one year, while somehow being sheltered from rain & snow. This can be in a shed, basement or even simply covered by plastic (black plastic is best) or a tarp.
OUR LOCAL FIREWOOD VENDORS USUALLY MEAN…
On the other hand, when local firewood vendors talk about “seasoned” wood, they usually mean simply that the wood was cut a long time ago, or was already dead when cut. The problem with this is that even if there is a month long dry spell, if the wood is left out in the open, when it finally rains, it absorbs as much or more water than what had evaporated in that dry month!
WHY IS USING DRY WOOD IMPORTANT?
All modern high-efficiency airtight woodstoves have to pass a tough test from the EPA to burn most all the smoke and creosote (the waste products from burning wood) right inside the stove. The best ones utilize these waste products as fuel to heat your home. The simple fact of the matter is that water will not burn, and wood left out in the open absorbs water like a sponge. Such wood can end up soaking up so much water that by winter, it the water content may be 50% of the weight of the wood! Such wood is unsuitable to burn well in any high-efficiency woodstove, whether catalytic or non-catalytic.
I JUST PURCHASED A STOVE DURING WINTER & ALL I HAVE IS WET WOOD- HELP!
Do get your wood off the ground and under shelter ASAP. You can use landscape timbers set down in rows to lay the wood pile on, or possibly free pallets, which many businesses give away constantly. It helps the wood to dry out faster if you split it finer. Be prepared to use lots of extra really dry kindling to help get the fire going. In order to make wet wood burn, you have to boil off enough of the water to get it dry enough to finally catch. Lots of energy just gets wasted just heating water into steam, which is then NOT available to make heat for your home! If you open the door, such smoldering wood makes fairly loud hissing, sizzling noises. Often, water can be seen bubbling and boiling out the ends. Eventually, such wood will finally make decent flames, but it takes a long time, and the self-cleaning glass feature offered by most better woodstoves will not be effective with wet wood. The good news is that given shelter, your wood will eventually dry out and be really good for burning the following heating season. In the meantime, expect your glass to run dirty, and make sure you really get the fire burning well before closing the damper (if your stove has one) or choking down the air.
WHAT SPECIAL TECHNIQUES ARE THERE TO COPE WITH WET WOOD?
When using a high-efficiency stove, a good way to know if your stove is really burning clean or is in the act of “glopping” up your chimney with creosote is to go outside and look at the exhaust coming from the chimney. When using wet wood, if you see little to nothing several minutes after you decided it was time to close the damper, congratulations… you have successfully burnt off most of the water and are currently burning clean. On the other hand, if you see a long trail of thick gray smoke, watch out! (Your stove has currently turned into a creosote machine!)
If your stove has both a damper (usually at the top of the stove) and a separate air adjustment control, make sure to leave the air control wide open (and the damper too) until the fire is ignited all over and is burning vigorously. (If your wood is really wet, that might not happen until half of the batch of wood is gone!) Then, close the damper, leaving the air control wide open for the time being. This will allow your high efficiency system the time it needs to pre-heat, “rev up” and get going properly. When it seems as though the fire is still burning OK even though the damper has been closed, then experiment with closing the air control some. If the fire looks “smoky” at the base, reopen the air control until flames, rather than smoke can be seen coming from the base of the fire. Adding some more really dry kindling on top of the wet wood is often helpful to “goose” the fire. Some local sources of dry kindling: handle mills, furniture factories, custom cabinet makers, free pallets. (Catalytic stove owners must not use painted, stained or otherwise treated wood, and cannot burn wood without removing nails or staples.) Also, when adding wood to a fire made with wet wood, be sure to fully open the damper, and the air control for a minute or two, then close the air control totally as you unlatch the door and leave it ajar for about a minute, to really get the flames flying up the chimney, to pull all the smoke up the chimney so you don’t get a face full.
DOES IT REALLY TAKE A WHOLE YEAR TO DRY THE WOOD ENOUGH?
In many parts of the country, it does take a full year. However, here in middle Tennessee, because of our long hot dry summers, we can usually get by having our wood split, stacked and covered in late winter or early spring (leave the ends of the pile open by folding back the plastic or tarp for good air circulation). We have good results with this schedule.
HOW CAN I TELL IF THE WOOD I BOUGHT OR CUT IS DRY ENOUGH?
This answer is straight out of one of our stove manufacturer's manuals (Courtesy of Enerzone International), and is excellent advice. It is called a "Simple Wood Moisture Test" which anyone can do:
"Add one large piece of wood to the top of an established fire. If it starts to burn on three sides within one minute, it is dry and seasoned and right for burning, If it turns black and starts to burn in about three minutes or more, it is damp. If it turns black and does not start burning until five minutes or more, it is green and wet. If it hisses at any time, the wood is soaked and will not burn until the excess moisture is boiled away."
WHY WILL WET OR GREEN WOOD NOT WORK IN MY NEW STOVE? MY OLD ONE BURNED GREEN WOOD ALL THE TIME AND WE HAD LOTS OF HEAT!
Remember, the energy it takes to boil water into steam will not be available to you as heat! Water will not burn. Many people remeMber that there old style stove seemed to put out plenty of heat even when using "green or wet wood." Think about this - todays's stoves burn smoke & creosote for half their fuel. Your old stove did not! Your old style firebox, to do the equivalent job, averaged at least twice the size becuase it needed to be fed twice the wood because you received much less heat out of each stick. You had to have a big, inefficient firebox, just like an SUV getting bad mileage needs a huge gas tank. Today's stoves are like a thoroughbred racehorse... it will not win the race when fed moldy hay with little or no training. You have to treat it a bit special to get it to win the race. So be it with today's stoves, whether catalytic or non-catalytic. Since we are trying to get much more "mileage" out of each piece of wood, it will not do to use wood that is 30% - 50 % of its own weight in water, and first try to boil this water off. The smoke will not start burning until you preheat everything to the point where the fire is burning all over the pices of wood you added. This will take a very long time when the wood is wet. You will have to waste a lot of the wood's energy that could have been heating for you and getting the smoke burning, onlly to evaporate enough water to get it hot enough to start the smoke burning.