Why do wood stoves make so much smoke?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Freshguy

New Member
Dec 14, 2019
3
Utah
In my view, the only "zero-carbon" heat source that makes any sense is a wood stove. But the best wood stoves make about 0.5 grams of smoke an hour. By contrast, a natural gas furnace makes about 0.0005 grams of smoke an hour. If wood stoves were able to match this, then the laws restricting use of wood stoves would go away. This is a very important issue that needs attention. Sooo____ why do wood stoves make smoke?
 
There are other issues with natural gas, but trees emit just as much or more carbon when they decompose in the forest. It's up to folks who operate wood stoves to be responsible for what fuel they choose to use.
 
In my view, the only "zero-carbon" heat source that makes any sense iwood stove. But the best wood stoves make about 0.5 grams of smoke an hour. By contrast, a natural gas furnace makes about 0.0005 grams of smoke an hour. If wood stoves were able to match this, then the laws restricting use of wood stoves would go away. This is a very important issue that needs attention. Sooo____ why do wood stoves make smoke?
Well burnt correctly with good fuel a modern wood stove should make no visible smoke once up to operating temperature. But burning solid fuel you simply will never get emmisions as low as you can burning gas. It simply is not possible. As far as the laws go without those laws wood stove emmisions would be much higher. Yes some companies would have developed clean burning stoves without being required to. But much of the market would still be made up of old design cheap simple steel boxed that would be very inefficient.

And for the record burning wood is not zero carbon. It is pretty low but definitely not zero
 
There are other issues with natural gas, but trees emit just as much or more carbon when they decompose in the forest. It's up to folks who operate wood stoves to be responsible for what fuel they choose to use.
Well that isn't quite accurate when decomposing yes wood does release carbon but allot of it goes into the ground. Allot of it goes into bugs that eat the wood etc. When burnt most of it goes into the air which is why burning wood is not zero carbon
 
Well that isn't quite accurate when decomposing yes wood does release carbon but allot of it goes into the ground. Allot of it goes into bugs that eat the wood etc. When burnt most of it goes into the air which is why burning wood is not zero carbon
Not quite zero, no but wild fires are a serious air quality and carbon emissions issue. Lighting striking a tree and setting a forest ablaze is way more damaging to air quality and carbon emissions than burning in an EPA stove. Burning responsibly by cleaning up the dead trees from the forest and promoting positive growth will help keep carbon emissions lower. Sure, none of this is proven, but I'm sure someone could do the math. Wood burning for heat or cooking in the first world is tiny, but there are wild fires raging all across the country (some went out finally) dumping carbon directly into the atmosphere. If the third world could be brought up to the same standards as the US and Western Europe then emissions from wood burning could be slashed again.

Perhaps wood is not zero carbon, but that's ok. It is sustainable and green compared to using energy to extract energy from the earth like coal, NG, petro, etc.

I think carbon neutral is a good term.
 
  • Like
Reactions: Easy Livin’ 3000
Not quite zero, no but wild fires are a serious air quality and carbon emissions issue. Lighting striking a tree and setting a forest ablaze is way more damaging to air quality and carbon emissions than burning in an EPA stove. Burning responsibly by cleaning up the dead trees from the forest and promoting positive growth will help keep carbon emissions lower. Sure, none of this is proven, but I'm sure someone could do the math. Wood burning for heat or cooking in the first world is tiny, but there are wild fires raging all across the country (some went out finally) dumping carbon directly into the atmosphere. If the third world could be brought up to the same standards as the US and Western Europe then emissions from wood burning could be slashed again.

Perhaps wood is not zero carbon, but that's ok. It is sustainable and green compared to using energy to extract energy from the earth like coal, NG, petro, etc.

I think carbon neutral is a good term.
I don't disagree at all. When it comes to heating properly operated woodstoves are pretty environmentaly friendly. Just not entirely zero carbon or carbon neautral. But pretty good nonetheless
 
  • Like
Reactions: Seasoned Oak
In my view, the only "zero-carbon" heat source that makes any sense is a wood stove. But the best wood stoves make about 0.5 grams of smoke an hour. By contrast, a natural gas furnace makes about 0.0005 grams of smoke an hour. If wood stoves were able to match this, then the laws restricting use of wood stoves would go away. This is a very important issue that needs attention. Sooo____ why do wood stoves make smoke?
There are tons of hidden carbon costs in natural gas. Some, like methane leakage, are exceptionally high. Fracking is carbon-intensive too. I was just reading about the large forest clearing that is done in order to mine the special sands they use in the fracking fluid. Nothing comes for free, but at least wood is a renewable and not a one-way street.
 
  • Like
Reactions: sloeffle
We agree wood stoves are much better than fossil fuel use BUT a "clean" wood stove produces about a thousand times more air pollution (smoke) than a natural gas burner. Are we content to admit we can't do any better? Why?
 
We are doing much better. Magnitudes better than just a few decades ago. New regs take place in 2020 that are the next step. It is not a trivial issue to make a user-operated (huge variable) wood-fueled (another big variable) device installed in a wide variety of situations to perform like an automated, controlled gas furnace.
 
We agree wood stoves are much better than fossil fuel use BUT a "clean" wood stove produces about a thousand times more air pollution (smoke) than a natural gas burner. Are we content to admit we can't do any better? Why?
Just simply looking at volume of "smoke" doesn't tell you a thing. You need to look at the chemical make up of that smoke. You need to look at what goes into getting that fuel from it's source to the heating appliance etc. Yes Nat gas burns far cleaner than wood ever will interns of pure volume of emissions. But that doesn't mean it is a cleaner fuel overall.

And the industry has been making wood stoves progressively cleaner over the past few decades. It just will never be possible to get volume of emissions down to the level of Nat gas.
 
While the average natural gas furnace may be much lower in particulates, it still emits plenty of CO2, CO and NOx.

Referring back to my earlier posting, here are methane emissions from oil and gas fields visualized. Methane is a much more serious greenhouse gas than CO2.
 
Last edited:
  • Like
Reactions: Easy Livin’ 3000
I think if we answer the question, why (or how) a wood stove makes smoke, then we can begin to make progress.
This seems to not acknowledge that we are making progress. Note that progress is costly. There are testing and experiments being done with scrubbers on the flue, but they add maintenance and cost. Also, pellet stoves continue to develop. They burn wood as compressed sawdust in a cleaner form yet. But they are often noisy and complex. Drop by the pellet forum here to see what these folks are dealing with. I also would recommend that you visit and maybe subscribe to the Alliance for Green Heat newsletter for more info on studies on this topic. They are doing good work. http://forgreenheat.org Every few years they have held a contest for worldwide stove builders to demonstrate the latest in clean-burning technology. I went to the first one and can recommend it as a great educational experience.
 
I think if we answer the question, why (or how) a wood stove makes smoke, then we can begin to make progress.
I really am not sure what you are getting at here. Modern wood stoves greatly reduce smoke when compared to stoves from just 35 or 40 years ago. Burning wood makes smoke. Woodstoves reduce that by creating more complete combustion. But that can only go so far. Can you tell us what you think a solution might be?
 
We agree wood stoves are much better than fossil fuel use BUT a "clean" wood stove produces about a thousand times more air pollution (smoke) than a natural gas burner. Are we content to admit we can't do any better? Why?

I'm content.

If people are really worried about carbon emissions from heating fuel, they need to get involved with insulating the houses in their community. This will also lower the emissions from fuel needed to run air conditioners in the summer too. It's simple, it's inexpensive, and very effective.

Focusing on cutting the energy needs of a community will produce greater results than focusing on a small niche group who heat with an alternative fuel source.
 
I sure one of your avg wildfires produces more smoke than all the wood stoves in america , so i wouldnt lose any sleep over feeling guilty about it.
 
I don't really understand why people always bring up natural events live eruptions and wildfires to excuse man made emissions. I agree those things release massive amounts of carbon into the atmosphere. But they would happen with or without us being here. We can't change that. We can change what we do.


And yes I know wildfires are influenced by human behavior as well. So that isn't a purely natural event.
 
Were all free to give up our wood stoves with their man made emissions if we choose. Can always go nuclear or wind generated electric heat if the guilt becomes too much to bear. We are already helping the situation here encouraging use of dry wood and cleaner burning efficient stoves to look at the bright side.
 
Last edited:
Im content
Focusing on cutting the energy needs of a community will produce greater results than focusing on a small niche group who heat with an alternative fuel source.
Very good point ,cutting your energy use in half is always a good idea no matter the fuel source. Im content as well.
 
I really am not sure what you are getting at here. Modern wood stoves greatly reduce smoke when compared to stoves from just 35 or 40 years ago. Burning wood makes smoke. Woodstoves reduce that by creating more complete combustion. But that can only go so far. Can you tell us what you think a solution might be?

1. Each year a wood burning appliance must be certified by a chimney sweep. No certification = no burning. (New houses need to be constructed in such a way that inspection is made easier - like roof steps).
2. All pre EPA wood stoves completely banned.
3. Outdoor wood burners that employ water jackets banned.
4. Conventional fireplace construction in new building banned and existing fireplaces must be updated w/epa inserts.
5. New house construction must employ passive solar concepts when possible and meet higher insulation rates.
6. Exterior chimneys not allowed in new construction - only interior chimneys.
7. 'Smart' technology used in wood burning.
8. Stricter regs to incorporate new changes as they are invented (like scrubbers/'smart' stuff).
9. ..........

I know this will never be done.
 
Let's give anybody who wants to buy a woodstove an intelligence test to see if they are too stupid to play with fire.

*obviously joking, but intelligence plays a part in woodstove operation.*

This thread has gone stupid.
 
Boy looks like the OP is very good at spending other folks money. I object to unfunded mandates and many of the proposed issues are unfunded mandates.

Sometimes there is lot to be said for the ignore member on this forum and this does seem another case.
 
  • Like
Reactions: kborndale
#9. All firewood sold must be certified tested to <20% moisture content.
Iv given up trying to explain this to some folks, otherwise intelligent people just cant seem to grasp this concept. Some will listen but i see guys burning for 10 yrs or more still burning wet wood(or trying to burn it).