Slow Burns

First of all, I have not extended the chimney; I am still trying to get a deal if possible. I may post on Craigslist; I did post on the classifies here; money is tight as always and I still have to do the repair on the bathroom.

My question is about slow burns. I have tried to do a slow overnight burn but when I do it smokes up the stove; the glass is solid covered as well as the firebrick; I had to really scrub to get the glass clean yesterday. Is this because of the wood or that I don't have the proper draft or what?

 

According to previous posts, your firewood is dry, but most of us still suspect the flue is inadequate. The weather here has gotten warmer, which also makes for slower burning and usually requires more air.
I'm still thinking of adding some pipe to my flue as well.

 

^^^^ This ^^^^

 

A slow burn will usually result in dirty glass, the slower moving air wash doesn't work as week as hotter fire. Slow bur s are dirtier, it's the way it is. Get used to it or run the furnace. Nothing about wood heat is clean.....

 

There is no such thing as a slow burn on that stove. You need to keep the internal temperature at 1000 degrees so the secondaries are lit. Otherwise it is polluting and coating your chimney. This is why cat stoves have a major advantage. They can function correctly down to 500 degrees inside and not pollute.

 

It seems like winter is over here but I know better. I guess it will be the same this year, everything will bud out and bloom and then bam, winter returns and kills it all.

OK, so are slow burns bad or good? I don't really mind that much building a fire each morning if that is the better way to go. I did not even have a fire yesterday or last night it is so warm here. I don't like warm weather this time of the year because I know what will happen to the gardens.

 

If you provided some details on how much wood your loading in the stove, what Stove Top and pipe temperatures you are seeing, what procedure you are using for dialing the air down and where is it at at the last setting?
Are you seeing any kind of secondary action in the top of the stove at any air setting ?
We could probably help you

 

In you stove slow burns are hard to do right. Your better off with smaller hotter fires if you have low heat demand.

 

The short answer: Set the draft lower and do so earlier in the burn before the stove gets too hot.
Watch your chimney for smoke, if it's smoking you are burning too cool (inefficient) and creating creosote.

 

I've had this EPA stove for 3 years now and I still go outside once in awhile to see how it is doing smoking or not

 

Each setup is different, do what works for yours.

Don't try to duplicate what you might see on here, 24,12,10 or 8 hour burns. If you can get a 5 hour burn but have to give your stove more air to burn clean, be happy with that.

 

That right there is very true. I think virtually all the problems that come from burning wood, dirty stove (inside), creosote, inefficiency, and similar all stem from trying to burn slowly. It is the hardest way to use a wood stove IMO, and it also shows the biggest difference between stove types (cat. vs. non- cat.) as well as stove brands and types, and also makes the wood being burned much more fussy.

The smaller, hotter fire idea is great if the stove has some mass and will retain heat for a while, or the house is very tight and well insulated, again holding onto the heat generated by the small, fast fire. But in an older house like mine, I basically need a constant wood fire to keep the house warm.... and when it is 45F outside, it is just about impossible to run the stove slowly enough to keep a clean fire burning for, say, 8 to 10 hours that will not overheat the house.

Using a woodstove is really pretty straightforward when it is 25F outside, the bigger challenges are when it is -5F (and that us usually pretty simple too- run the stove hard, fill it as much as humanly possible and hope the fire lasts until morning) and when it is 50F outside.

Brian

 

This is where the discount stoves have a disadvantage. There are a lot of great technologies out there for a slow burn, just not under $1000. Cat stoves, hybrids, soapstone, cast iron jacket, thermostat controlled, etc...

A general secondary burner really has no low end capability. It must have a high internal temperature to operate correctly. They cannot be smouldered and burn clean.

 

Did you post an outside pic of your stack, or did I miss it in the other thread? I don't think you'll have much success burning lower until you can get more stack up there. You'll have to fire short, hot loads until then.
It's 50s and damp out, and it got down to 66 in here. I had no choice but to fire a short load of Cherry.

 

Good post, and exactly right in my experience and opinion. To go a step further, secondary burn stoves (non- cat) actually have advantages over pure cats. stoves on high burn settings; look at the output from a pure cat. stove and the emissions go up as the burn rate increases. That is because the cat. cannot burn the fire's by-products (smoke) fast enough when the fire is burning quickly. The exact opposite is true of secondary burn stoves; the secondary burn increases in size to consume more of the emissions as the burn rate increases.

Which of course brings up to the best of both worlds: the hybrid stove. At low burn rates, the firebox is black and the fuel is smoldering but the cat. burns the smoke exactly like a pure cat. stove. But as the rate of burning increases, the secondary burn starts which consumes part of the smoke, then the combustor consumes most of all that remains. Once in a hard burn, the cat. temperatures actually FALL below the firebox temperature, indicating that the cat. is no longer being fed much, if any, fuel and everything is consumed by the secondaries in the top of the firebox. It really is a nice step forward in wood stove technology IMO.

Finally, the ultimate way to 'burn slow' is to burn very fast and very hot but store the heat for use over time. The two ways I know of to do this are by using what is called a 'Russian' stove, which is basically a huge assembly of rocks, cement and so forth and build a fireplace in the middle of it and route the smoke through the rocks (sideways and even downward in places). The other way is with a wood boiler and lots of boiler water storage. Both devices work basically the same way: a very fast, hot fire is used to heat the media (rocks or water, depending on the heater type) and then the fire goes out but it burned very cleanly. Then the rocks slowly radiate the heat into the house, or the water stores the heat until needed and a pump is used to move the heat from the water storage into the building (via baseboard heat or similar). Both systems are really excellent but are large, complex, very expensive and take up a lot of room. I think the hybrid woodstove is the next best and most practical way to burn wood efficiently.

Brian

 

Even with a cat stove...

 

What BDF said!

I have found it is impossible to burn low slow and clean in a non cat stove, and to get the high burn BTU's I want for the coldest nights would require a very large cat stove that won't work with my 6" chimney. That is why I decided to spend the cash on a hybrid.

 

The best thing you can do is forget about slow burns and do a few short hot fires.

 

I'm glad I built with a lot of thermal mass in my house. I adjust my burn rate to keep it clean and let the house smooth out the temperature. I came home after being away this weekend (when it was still cold- it has been in the high 70s this week!) to find the same wood in the woodbox that was there when I left. No fire in 2 days, but the house was 68. We went away for a week last March and it was 64.