Efficient Wood Burning Stoves

Modern woodstoves are an economical and environmentally sound choice for home heating. Wood has a much higher BTU capacity than gas, and wood is a renewable resource.

Older, conventional woodstoves emitted between 30 and 80 grams of particulate matter (smoke) per hour, while the new EPA-approved stoves have reduced emissions to between 3 to 6 grams per hour (a reduction of over 90%).

There are some woodstoves available that achieve a burn efficiency of 70-80%. Many of these efficient stoves can be found for sale at Fireplace Warehouse. This Washington-based company has a lot of information online about stove efficiency, because Washington state has stringent woodstove laws which exceed even the new EPA Phase 2 requirements.

Comments

Hey! I was thinking about getting one of these. My husband is just very, very afraid of the house burning down. *sigh* This was even after I calculated that it would almost totally eliminate the need for supplemental heating at our house. I’ll keep working on him though 😉

Metaefficient is off thier rockers. Burning wood is environmentally efficient — hm, is it because you kill trees that take CO2 out of the air, and burn them to get CO2 back into the air, or is it because trees are just generally bad things to have around. There are alot better way to get heat.

Wood is a renewable resource, which means that it can be restored and replenished by nature in a period of time that is compatible with our human use. Provided they are cared for and managed properly, our forests can be a perpetual source of fuel, unlike gas, oil, and coal, which we are being depleted at a rate that is astonishingly faster than the millions of years it took Nature to make them.

Greenhouse gasses. All fuels produce carbon dioxide, the primary greenhouse gas, when they burn. When the atmospheric concentration of greenhouse gasses increases, they cause the average global temperature to rise.

Wood differs from the fossil fuels coal, oil and gas, because it is part of the natural carbon/carbon dioxide cycle. As a tree grows, it absorbs carbon dioxide from the air and stores it in the wood as carbon, which makes up about half of the weight of wood. When the wood is burned, carbon dioxide is released back into the atmosphere. No additional carbon is released because the same amount of carbon dioxide would be released if the tree died and were left to rot on the forest floor. The carbon in coal, oil and gas, by contrast, are taken from underground stores, where they were deposited by Nature, and released into the air without means for equal reabsorption.

When trees are used for energy, a part of the forest’s annual growth is diverted from the natural decay and forest fire cycle into our homes to heat them. Both natural firewood and firelogs — made by compressing waste sawdust — are energy products from the forest. Burning wood actually helps reduce greenhouse gas emissions by displacing the use of oil, gas and coal.

Air pollutants. Smoldering, smoky fires that produce a plume of blue-grey smoke from the chimney are the main cause of wood heat-related air pollution. Wood smoke can be harmful when it is inhaled. That wood smoke has become a major air pollution problem in many communities has led to both local regulations and more efficient wood-burning appliances.

Joe assumes that one needs to cut down living trees in order to burn wood. This is a false assumption. There is an enormous amount of blown down, fallen branches and dead standing trees to heat many homes on a sustainable basis. In addition, decaying trees produce methane gas which is a seven times more potent greenhouse gas when compared with carbon dioxide (combustion products). While wood is not a practical means to heat all of the USA, it is a viable and preferable technology in many local areas where dead scrap wood is abundant.

I have heated with wood for 23 years and have never had the need to “murder a living tree” other than some selective cutting of diseased or badly damaged trees. Dead trees release CO2 as they decay.

An erroneous assumption is that “man made” CO2 is the CAUSE of climate change an as such must be regulated. People, if you take the time to REALLY READ the data and take out the MAN MADE statistical manipulation to support global political agendas, you will find that climate change fast slow and otherwise has occurred ALWAYS and will always occur. If you don’t believe this, go to your local museum and look at Exhibit A: The Dinosaurs (your pick of period) The history would indicate that the entire earth was much warmer for 100’s of MILLIONS of years. Next go to Exhibit B and check out the ICE AGE’s that generally lasted Thousands of years and are generally caused by 1: Meteor Strike or 2: Major Volcanic Activity 3: Untested – Thermo-nuclear war.

joe obviously you need a bit of education. Most people burn trees that are already dead. Green wood or living trees do not burn well so we clean up the dead and dying trees and utilize them for fuel. This also can help with spreading of fires and promotes new growth.

Joe, you don’t mention what those “other ways” of getting heat might be. Here is the reasoning behind wood burning, courtesy of the Worldwise web site:

Wood is a renewable resource, which means that it can be restored and replenished by nature in a period of time that is compatible with our human use. Provided they are cared for and managed properly, our forests can be a perpetual source of fuel, unlike gas, oil, and coal, which we are being depleted at a rate that is astonishingly faster than the millions of years it took Nature to make them.

Greenhouse gasses. All fuels produce carbon dioxide, the primary greenhouse gas, when they burn. When the atmospheric concentration of greenhouse gasses increases, they cause the average global temperature to rise.

Wood differs from the fossil fuels coal, oil and gas, because it is part of the natural carbon/carbon dioxide cycle. As a tree grows, it absorbs carbon dioxide from the air and stores it in the wood as carbon, which makes up about half of the weight of wood. When the wood is burned, carbon dioxide is released back into the atmosphere. No additional carbon is released because the same amount of carbon dioxide would be released if the tree died and were left to rot on the forest floor. The carbon in coal, oil and gas, by contrast, are taken from underground stores, where they were deposited by Nature, and released into the air without means for equal reabsorption.

When trees are used for energy, a part of the forest’s annual growth is diverted from the natural decay and forest fire cycle into our homes to heat them. Both natural firewood and firelogs — made by compressing waste sawdust — are energy products from the forest. Burning wood actually helps reduce greenhouse gas emissions by displacing the use of oil, gas and coal.

Air pollutants. Smoldering, smoky fires that produce a plume of blue-grey smoke from the chimney are the main cause of wood heat-related air pollution. Wood smoke can be harmful when it is inhaled. That wood smoke has become a major air pollution problem in many communities has led to both local regulations and more efficient wood-burning appliances.

Can anybody tell me why I am getting CO2 back into my house whenever I let my woodburner cool down – or better yet, how to prevent it? It is not excessive levels but enough to make the detector chirp. I am able to clear the air with a fan and open window in 10 – 15 minutes.

That’s a confusing question to begin with. You produce CO2 when the fire is hot, not when it has cooled down ( what do you mean by that )? I have been heating with wood since 1974 using a homemade insert until 1986, then a woodstove, and then a more efficient woodstove in 2001 I have a CO2 detector that has fooled me a couple times, but all it needed was a new battery. How about when your stove is hot and burning normally? No detector sound? That’s odd, so the only thing i can think of is: as you are letting your fire “cool down”, open your draft-control fully, because even though the fire might not be out, there could be some small embers burning, so the draft tends to decrease when stove is cool. Another thing. If there actually is some CO2 leakage, it will be coming from either a bad door gasket ( replace that every 2 or 3 years for safety)…….or where the stove-pipe enters the stove. The stove cement in some cases needs to be replaced every year, so i guess it is coming from 1 of those places. Good luck

Hey vic I think that when your stove cools down the up draft produced by the fire itself is diminished enough that there is not sufficient airflow to bring the smoke up the chimney. You may have to clean your chimney to let the smoke out (and prevent a potential fire in it) , or just open your damper on your stove a little to produce more updraft.

Joe assumes that one needs to cut down living trees in order to burn wood. This is a false assumption. There is an enormous amount of blown down, fallen branches and dead standing trees to heat many homes on a sustainable basis. In addition, decaying trees produce methane gas which is a seven times more potent greenhouse gas when compared with carbon dioxide (combustion products). While wood is not a practical means to heat all of the USA, it is a viable and preferable technology in many local areas where dead scrap wood is abundant.

I have seen this wood burner debate go both ways for years. Fact trees are carbon neutral. There are plenty of dead or damaged one to help warm your house. I agree if we used trees for our only fuel source as we use energy now, we would be in trouble. I have been burning wood for years, I have had the old smoky burning wood stoves, and now a clean almost zero smoke version now. The best wood for cleanliness is good dry, seasoned pine. The most smoky has been red and white oak. Best bet if you want to get into it is, get a EPA rated stove and burn only dry, seasoned and properly sized firewood.
But, I do agree it is not for everyone. Choose wisely.

Wood stoves can be designed to be “super efficient”. It is simply a matter of providing conditions for complete combustion followed by effective heat recovery. Complete combustion requires temperature, time, turbulence and excess air. Most wood stove designs lack adequate turbulence and sufficient excess air. Complete combustion eliminates all creosote.
Heat-Booster Energy Systems is currently operating converted old non-EPA wood stoves with no visible smoke and 90% energy efficiency. This efficiency means that 90% of the energy released by combustion goes into house to be heated. Typical operating conditions are 750°F on stove top near flue gas exit and 160°F at heat exchanger exit. An optional catalytic combustion unit is used for “polishing of flue gases. Hot air from heat exchanger can be used to heat water when an optional finned coil is installed.
Draft problems can be solved by installation of draft inducers.
Bottom line is that it is possible to have complete combustion and super high energy efficiency.