Oregon State University researchers are getting their PhD's in wood burning (just joking)

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Whitenuckler

Minister of Fire
Feb 16, 2025
603
PEI Canada
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Thanks for that 'real' assessment on woodburning stoves. I've never seen it laid out so clearly. Top points I took from this,

".......showing that 70% of the pollution emitted from wood stove flues happens at two points in time: when a stove is first lit, and when it's reloaded.........." I wonder how to better reduce these startup and reload problems?

"...........wood stoves, they are the U.S.'s third-largest source of particulate matter pollution, after wildfire smoke and agricultural dust,..."
I was surprised here.

"........there are an estimated 6.5 million inefficient stoves in the U.S., most of them models that predate EPA clean-burning standards. In all, there are roughly 10 million wood-burning stoves in the country,...." That means more than half are polluters. There is one obvious solution.

".....developing automated technologies that inject jets of primary and secondary air into the fire to provide just the right amount of air and mixing at the right time and place in the fire. Prototypes are showing about a 95% reduction in particulate matter emissions compared to older models....." Darn, I wish I had put in the masonry heater I built air channels between brick layers in the firebox - so extra air to the firebox. But I did not.
 
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Call me skeptical about it being the 3rd largest source of pollution.
 
Call me skeptical about it being the 3rd largest source of pollution.
Yes, I'd like to see the source. Sounds like they may be including fireplaces and open outdoor fires like firepits and garbage burners. Still, this would have to be seasonal.
 
The article doesn't specify, but I suspect that it is based on old data or data based on pre-EPA stoves. Overall, the trend is good. Agriculture remains a top contributor. The rest varies hugely depending on the region and time of year, with industrials and road dust coming higher in urban areas, especially in the south.

[Hearth.com] Oregon State University researchers are getting their PhD's in wood burning (just joking)
 
I suppose it’s possible their total number of stoves could be accurate. It seems low to me. But if they collected data from insurance companies it could be fairly accurate.

I’d bet the majority of stoves in people’s houses aren’t used often. I’d bet this is especially true of pre EPA stoves. EPA regulations started in what 92 or 93? 30 years of hard seasonal use is going to wear things out. The majority of survivors were well maintained (most never were) or not used much.

If their particulate figures are based on these stoves running hard every night they’d be off by a lot. I bet a lot of the EPA stoves just sit. They were purchased for emergency use, only used for ambiance, ran a few times with wet wood and frustrated the user… we see the posts here. How many people just quit rather than take the effort to sort the stove out, even if it takes a year to dry the wood enough to do it.
 
I think you aren't being realistic. There are many who use old stoves (especially in rural settings) and burn unseasoned or partially seasoned wood in these old stoves. They have developed this pattern and are now set in their ways. It works, it heats why change?
We see it on this site day after day - "I want a fireplace.......My old wood stove is better than any EPA stoves....Wood is wood it all burns....I can heat my shop, my house, my garage with my homemade wood boiler......Will this Oak be ready by next year?... .etc..."
 
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Call me skeptical about it being the 3rd largest source of pollution.
Right?!
If they are really so worried about it, how about taking a BIG swing at reduction, do some forestry management and stop these wildfires that block the sun for half the summer on our continent!
 
I think you aren't being realistic. There are many who use old stoves (especially in rural settings) and burn unseasoned or partially seasoned wood in these old stoves. They have developed this pattern and are now set in their ways. It works, it heats why change?
We see it on this site day after day - "I want a fireplace.......My old wood stove is better than any EPA stoves....Wood is wood it all burns....I can heat my shop, my house, my garage with my homemade wood boiler......Will this Oak be ready by next year?... .etc..."
Are you debating the number of old stoves out there, the percentage of old stoves vs new stoves, or how often the old stoves out there are used?
 
How often they are being used. Although if as you say many old stoves aren't being used, if this study is correct there are twice as many of them compared to new stoves so even if many aren't being used there are probably more old stoves being used compared to new stoves. So realistically when a person says wood stoves are major polluters there is a basis for saying this - because those old stoves are polluters.
The good wood stoves are brought down by all of the old stoves. So I could say, "Overall wood stoves (boilers, inserts, fireplaces) are a major source of air pollution." Would I be wrong?
 
I think we can agree that they do polite, but would probably disagree as to whether or not it’s major.

I’m not sure that that there are more old stoves in constant use as there are new ones. Again, it’s been 30 years since they were sold on a widespread basis. I realize there were a few “exempt “ stoves sold but percentage wise it was very few. I’d bet, just like we see here, somebody buys a house that has an old stove in the basement that hasn’t been used in years. They might use it a year or two, realize the work involved, and either leave it unused or replace it hoping to use 30% less wood.

Old stoves are like old cars. Yes, they don’t run as clean, but in the Northeast at least, there really aren’t a lot of them around to pollute anymore. Those that do are not daily drivers. Running them on the weekends for part of the year isn’t going to make much of a difference.

How to deal with it is probably different also.

Since so much money would be spent for incremental gains going from 1.5g/h to 1g/h, or less, I’d focus on ways to make houses need less heat. I’d put that money into insulation. That’d help keep heat in during the winter and out in the summer. Fewer splits would be burnt regardless of the stove’s age and our air would be cleaner.

Making other forms of energy for heating that make less pollution more easily available and affordable is also a good option. Natural gas is cheap and much less work than wood. My electricity bills s really expensive, but other places have it cheap.
 
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Without citations of data source(s) we can only speculate on the validity or errors in the assumptions in the article. On the surface, they look cherry-picked, possibly out of date, and potentially regional and/or seasonal. They dilute message. The underlying point is already well known - old stoves and open fireplaces put out a lot of particulate matter.
 
I now go into a lot of people's homes for site visits in my current job for gas appliances' gas lines, how they will be ran, gas inserts and free standing gas stoves, and log sets. I'm still shocked at how many old wood stoves (Pre EPA) are still in people's homes. Some say they still use them, some say they don't, that these stoves are a catalyst for the new gas appliance. I'm in smalltown Connecticut and its this way, a large area of wood stove usage. I sold wood stoves for 20+ years at a couple of large hearth dealers, it always seemed to me that we sold a minute amount of new stoves to the amount of old stoves (Franklins, all-nighters, Atlanta stove works, original VC's) that are still out there heating homes. They belch smoke, and as much as we all promote clean burning technology, folks still hold on to the old stuff that works. I've always been amazed at it. This article is interesting, but I too question their numbers. The only thing we can do is try to put the facts out best as we can. Having said this, I still love my old 2009 Enviro Kodiak, its clean burning, but not the cleanest. I am totally against telling someone they cannot use their old stove, but it'd be nice to find a way to induce them to want to replace it. Can't see that either with stove prices going up every day. We'll do the best we can.
 
A lot of those old, idle, wood stoves are kept around in case there is an extended winter power outage and for extreme cold events. Many are not used for years.
 
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Yup, we have friends with a big ole black cast iron thing taking up real estate in their living room, and they dont use it...but it's left there "for emergencies"...they have talked about getting a modern stove and actually using it, who knows, I think money is a bit tight for them. (Single income, and small kids)
 
If it’s for emergency use, it’s hard not to stay with a smoke dragon. They burn sub optimal wood easily. If you’re trying to scrape by, something that’ll turn that tree that just came down into heat is hard to argue with!
 
I sell firewood once in a while. From what I have noticed where I am at - southern Idaho, most people are buying firewood for heat. Many are using pre-EPA stoves. One contractor did his research and was using a new Blaze King. Another guy was buying 4 cords for heating. His setup was pre-EPA stove in prime condition.

I tried to encourage a new stove's benefits but he wasn't interested. At least he is burning dry wood. I wouldn't be against other states following Oregon's lead - no fireplaces in new construction. Additionally, pre EPA stove ban with a few $$$/rebates to steer them towards modern stoves. Let's recycle that metal and turn into something that burns better. Stove 'brains' are hopefully coming to optimize the burn. This is the obvious next step in all wood burning appliances.

On the next Masonry Heater I build, this means cutting out little air channels between the 2 layers of fire brick in the firebox. I guess a little air fan could be added, too. Although I've never seen anyone doing this (in North America, anyway). I would have to work the fan manually because the electronics needed to sense the oxygen levels in the fire and then send this info to the fan are beyond me. I guess that is what these scientists are working out.
 
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I too believe that a lot of folks don't want to "disturb the mess" of getting an old stove out of the house, if not replacing, is still an expense many don't want to deal with. Keeping it for that emergency is just easier to do. Fortunately, I've never had to deal with a smoke dragon at a neighbor's house, when I bought my home in the mid 90's, I was the smoke dragon person, had an old Better N Ben's free stander. Got rid of it soonest too... still lots of fireplaces in CT with nothing in them. I wished the state would make incentives for replacing the older stoves, at various times we have had that movement here in New England, now the push is to get rid of fossil burners, but so far the wood stoves have been left alone.
 
Smoke dragons can be burnt relatively clean when dry wood is used. I have one in my basement and the only time it gives off smoke is on reload. Once it is cruising along you couldn't tell it is lit by looking at the chimney. I see plenty of new modern epa stoves that burn wet wood and smoke out the neighborhood. A smoke dragon burning dry wood burns cleaner than an EPA stove burning wet wood.
 
Just because you can't see smoke doesn't mean your pre EPA stove isn't polluting. You see the above user represents a blueprint of how many people think. This belief that the good ol' stoves are damn near as good (probably better!) than these finicky government forced-on-us stoves. That is why I think this study is probably closer to the truth than closer to being false.
 
Just because you can't see smoke doesn't mean your pre EPA stove isn't polluting. You see the above user represents a blueprint of how many people think. This belief that the good ol' stoves are damn near as good (probably better!) than these finicky government forced-on-us stoves. That is why I think this study is probably closer to the truth than closer to being false.

A smoke dragon burning correctly with dry wood will burn cleaner than a modern stoves choked down with wet wood. And unfortunately many people burn their modern stoves choked down with wet wood. Just because it's an EPA stove does not mean it is going to burn clean. How you burn is more important than what you are burning in. Yes, ab EPA stove burning correctly with dry wood will be cleaner than a smoke dragon doing the same but a smoke dragon can still burn clean if you allow it to.
 
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I disagree that a smoke dragon can burn cleanly in optimal burning conditions - ie dry wood, good draft, etc... These are a square metal box - period. How can wood burned in a metal box be clean burning? It can't. Particles and pollutants head right out of the stove pipe. There is nothing to stop them. Even in optimal conditions these stoves are still polluting. Of course wet wood in any stove is going to cause pollution. The future probably goes like this - air controllers in all stoves with air sensors for complete burns, hybrid tech. in all stoves, and finally some sort of scrubbers at the very end to catch anything that gets by.

I guess you could stuff an old stove with fire brick and a block off plate to get it to act a little bit like a masonry heater - that is getting the insides hot enough to burn off some of the smoke you are delaying. But most are just loading these stoves up and burning the wood.
 
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I think all agree it's good to burn clean. I for one though, am not interested in limiting what one can burn, or taking the ability away to burn. My hope is we can induce folks to want to burn clean and safe, the biggest issue I see is stove cost, hopefully it gets better.
 
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