Switching to an EPA stove?

[laynes69]

There's alot of heat within a coal bed. If I had 3 to 4 inch coal bed, it would take the skin off my hand if I touched the glass on our furnace. On a EPA stove, many people see useful heat on a 300-400 degree stove when there's a coal bed. There's no blower cooling it, so there's no recovery of heat, just a steady output. What you've created is a bit different than a standard EPA stove, so it's not going to burn like a stock unit. Also a EPA stove or furnace requires a stronger draft than those without all the air channels.

Our furnace puts out great heat and often on a coal bed, but it's designed different. The secondary heat exchanger extracts a bit more heat and the automatic damper burns down the coal bed at night. If heat is needed, it ramps the coals up almost white and when the house is met it closes the damper preserving those coals. When we wake up, the front of the firebox is ash while the coal bed remains in back. With our old furnace it was the opposite, very little heat on a coal bed, and with the grate the fire was dead quite a few times in the morning. Now I can heat our home for hours with a coal bed. I also can attribute this to decent insulation and great efforts for airsealing. Two things that pay off big.

 

[ancy]

It took me a good season to really figure out how to make my stove really cook and have nothing but ash not wasted charcoal. That said it does take 30 minutes to get to temp from cold but why let it get cold?

Sent from my XT881

 

[Whitespider]

yep, I understand all that laynes69.
And I have plenty of (too much) draft... actually have a flue damper installed and half closed (much of the time) to control it.

The thing is, I've made a "real world" comparison of two different types of fireboxes, both from stoves and converted to furnace configuration, in much the same manner (in fact I used the old one as a pattern of sorts). Both used the same chimney, same length of flue pipe, same forced air system, burning the same fuel(s), etc. Really, the only reason the EPA firebox capacity is smaller is because of the brick and baffle, the outside surface area is darn near the same. The fact remains... the EPA firebox burns cleaner and produces quite a bit more heat at peak... the old smoke dragon reached peak heating much faster and sustained it for a much longer period of time while completely consuming the fuel load during that time using the same size fuel load (even though the EPA box capacity is smaller I rarely needed to "fill" the old one).

I guess it comes down to what you believe is "more efficient". Personally, I'll take the faster, longer lasting peak heat any day (even if it ain't quite as warm) so I'll be trying some modifications to achieve that... and cleaner emissions won't be a part of the concerns. Seriously, I wouldn't purchase a new furnace at the prices they cost, I can build a new firebox for less than the cost of a set of cheap tires... and I've built them before. But I'm confident, with a bit of altering and/or de-EPA-ing, I can make this one do the job better than the last.

I mean... it's fire after all... it ain't all that complicated.

 

[Whitespider]

I think part of what is happened in this thread is that some have the "latest" and are totally convinced that automatically makes it the "greatest" (or maybe they just want to believe)... I don't fall into such traps. My observations and complaints are legitimate... that don't make the "new" necessarily "bad" (and I never said it was)... but my observations and complaints are legitimate, whether some refuse to admit it or not.

 

[Eric Modell]

Spider in the past you would give me grief for burning green wood if I wanted to. I think it is great that you are enginnering and making it work for you. One size does not fit all. I had physics teacher that would tought every class there is always a trade off, if you gain in one area and loose in anther it is just life, and it is always a trade off to achive the desired results.

 

[slowp]

Walter FITZPATRICK, Wayne E. Hall, William J. Hutchinson,
Thomas Jones, Darryl J. Levette, Miguelito Marcelli, Andre
D. Mitchell, Dennis Bernard Thomas, Melvin Whitehead,
Gregory Wilkinson, Alfonzo L. Williams, and Elton M. Worthy,
Plaintiffs-Appellants,
v.
CITY OF ATLANTA, Defendant-Appellee.

No. 92-8306.

United States Court of Appeals, Eleventh Circuit.

Sept. 27, 1993.

This suit was brought against the City of Atlanta ("the City") by several African-American firefighters employed by the Atlanta Department of Public Safety, Bureau of Fire Services ("the Fire Department") who suffer from a medical condition on account of which they cannot shave their faces. Plaintiffs challenge a fire department regulation that requires all firefighters to be clean-shaven. They allege (1) that this "no-beard" rule has a discriminatory disparate impact on African-Americans in violation of Title VII of the 1964 Civil Rights Act, 42 U.S.C. Sec. 2000e et seq.; (2) that the no-beard rule was adopted for racially discriminatory reasons in violation of Title VII; (3) that the rule discriminates against the handicapped in violation of Sec. 504 of the Rehabilitation Act of 1973, 29 U.S.C. Sec. 794(a); and (4) that the rule infringes the firefighters' constitutional right to substantive due process of law.1 The City defends the policy, contending that the respirator masks used by firefighters cannot safely be worn by bearded men. The district court granted summary judgment for the City and the firefighters have appealed. For the reasons set forth below, we affirm the judgment of the district court.

Wait til you see USDA ammendment 8 !!!

Those are city firefighters. The wildland fire crews do not use respirators.

 

[bcorradi]

The other thing that people don't really understand is there are so many variables involved with stove performance: different climates, square footage, stove location, insulation RValue, windows, etc.

If I remember right Del u live in Georgia right? I'd probably be comfortable heating my whole house with a large candle if I lived there. Two nights ago it got down to about 17 degrees I believe (fairly mild for this time of year) and I had a fire in the stove and let it burn out yesterday morning. Yesterday it got up to 44 degrees (extremely mild for this time of year) and I didn't even start up until this evening eventhough today's high was only 30 degrees. So in the end Del u may be happy with your Jotul stove in your house, but i bet you would think differently if you took your whole 1890's house and stove and parked it in the middle of the windy flat plains of Iowa, Minnesota, South Dakota, Wisconsin, or North Dakota. Eventhough it works great for you, your house, and your climate that doesn't mean it would perform well in other climates.

 

[Arbonaut]

Those are city firefighters. The wildland fire crews do not use respirators.

Agreed.

 

[Arbonaut]

The other thing that people don't really understand is there are so many variables involved with stove performance: different climates, square footage, stove location, insulation RValue, windows, etc.

If I remember right Del u live in Georgia right? I'd probably be comfortable heating my whole house with a large candle if I lived there. Two nights ago it got down to about 17 degrees I believe (fairly mild for this time of year) and I had a fire in the stove and let it burn out yesterday morning. Yesterday it got up to 44 degrees (extremely mild for this time of year) and I didn't even start up until this evening eventhough today's high was only 30 degrees. So in the end Del u may be happy with your Jotul stove in your house, but i bet you would think differently if you took your whole 1890's house and stove and parked it in the middle of the windy flat plains of Iowa, Minnesota, South Dakota, Wisconsin, or North Dakota. Eventhough it works great for you, your house, and your climate that doesn't mean it would perform well in other climates.

In the real world is where we bridge the gap between theory and practice. Heating with solid fuel successfully means being prepared and being realistic. I just throw massive BTU's at it. I'm not the pointiest spoon in the fork, however. I like an airy house cause it keeps our immune systems up. Keeping it 70 degrees F above the outside temp is a piece of cake. It just takes tons of wood.

 

[cmsmoke]

I think part of what is happened in this thread is that some have the "latest" and are totally convinced that automatically makes it the "greatest" (or maybe they just want to believe)... I don't fall into such traps. My observations and complaints are legitimate... that don't make the "new" necessarily "bad" (and I never said it was)... but my observations and complaints are legitimate, whether some refuse to admit it or not.

http://www.arboristsite.com/attachment.php?attachmentid=262426&d=1353034033

 

[ancy]

Those are city firefighters. The wildland fire crews do not use respirators.

We do, but I'm sure you know more than me!

 

[bcorradi]

We do, but I'm sure you know more than me!

Of course she does, but don't move here.

 

[Steve NW WI]

Seriously, I wouldn't purchase a new furnace at the prices they cost, I can build a new firebox for less than the cost of a set of cheap tires... and I've built them before. But I'm confident, with a bit of altering and/or de-EPA-ing, I can make this one do the job better than the last.

How about putting some insulation in that "old uninsulated farmhouse" - your words from various other threads, and not need constant full heat, instead have enough "power" to turn it down a notch and enjoy slow steady heat?

Oh yeah, that'd be "working smarter, not harder".

If being cheap's your main concern, they still make barrel stove kits. That'd be a heckofa start on a new furnace, and you'd have enough change left over for 2 cheap tires.

 

[Whitespider]

oh yeah, that'd be "working smarter, not harder".

smart azz!

Actually, I've started doing a few upgrades to the house along those lines... slowly, and a little at a time.
It's time for paint again, considering covering it in vinyl siding this time, which would make it easy to put some nail-up insulation on first... but before I do that, or maybe at the same time, install replacement windows. But still, it all requires time and dollars.

The wife is thinking she'd like to give a major facelift to a couple rooms, which would probably mean tearing out the lath & plaster, replacing with drywall... making it easy to insulate those rooms anyway.

And so-on, and so-on...

 

[Whitespider]

Another misconception you have is that in an EPA stove you pack it as full as you can, light it off and leave it be for 10 or twelve hours. If you want quick heat in an EPA stove you start a smaller hot fire and then add wood after an hour or so.

Ok, I'm not a closed-minded person
I'm willing to accept the possibility that I need to modify my technique some, that the learning curve ain't over yet... and this morning is a bit of proof to that.

I've been studyin' how the air is delivered in this new firebox, how it flows and whatnot. Maybe the idea of putting the secondary air on a separate control may not be such a good idea (but I haven't tried it yet). The upper secondary baffle also supplies the door with air-wash (which may be partly why the front and door cool with a coal bed); it flows down and into the lower part of the box... restricting that could have the negative effect of also reducing air to the fire (unless major changes are made to the lower air delivery system... something I'm not willing to do... yet).

So anyway, it's colder this morning, down in the mid-20's and I'm wantin' some quick(er) heat. Thinkin' about how the air flows, I didn't lay the bottom row of splits tight against each other... placed them about an inch or two apart. This had the effect of creating larger air channels under the rest of the fuel load... and the fire engaged the secondary burn quite a bit faster... and fairly good heat from the vents came somewhat sooner. I won't say it was as fast as the old smoke dragon, but certainly noticeably faster than I've been getting... and, I must admit, fast enough to live with.

As far as getting more heat from the coal bed... not sure how a technique change can alter that. I have learned that stirring up the coals, pulling/banking them forward in the box, and opening up the air supply will make them heat more... which I don't mind doing, but that don't help much for overnight burns when I'm sleepin'.

 

[Marc]

I mean... it's fire after all... it ain't all that complicated.

I've been reading this thread with some interest, since I'm an engineer with a concentration in thermo/fluids. I like that you're trying to understand how a device works, what it was designed to do and then modify it and use it to suit your needs.

It reminds me of a quote from one of my most favorite movies, Apollo 13; Flight Director Gene Kranz: I don't care what anything was designed to do. I care about what it can do.

That being said, I only take slight umbrage with your attitude expressed above. Trust me, fire is complicated. Fire is very, very complicated. Of the more traditional science and engineering disciplines, our understanding and ability (or lack thereof) to predict fire behavior is about on par with medium range weather forecasting. The two systems are actually fairly comparable in complexity. We can write the exothermic chemical reaction for complete combustion as fuel(s, l or g) + O[SUB]2[/SUB](g) → CO[SUB]2[/SUB](g) + H[SUB]2[/SUB]O(g) + *energy* but that doesn't even tell a fraction of the story. There can be up to on the order of hundreds of intermediary reactions taking place during that transition before things settle into your gas products. That's not even including nitrogen, which is typically included with the oxygen as part of combustion air, that interacts with the reaction, absorbs heat and winds up back as nitrogen again on the other side. And that's just for "simple," complete combustion. Which happens in a stove exactly zero percent of the time.

Now take into account you have another set of very complex endothermic chemical reactions taking place to turn solid fuel into gaseous volatiles, called pyrolysis which must absorb enough heat from combustion to self sustain the reaction system. I haven't even started in on ignition and flame spread.

We don't even have very good computer fire modeling because there is so much to account for and so much randomness in the system. We're getting a lot better at predicting smoke and heat transport in a structure, but we're still, for the most part, estimating the input fire size and how fast it will grow based on empirical data. And even then our model validation shows us we can sometimes be 30% accurate at best for certain configurations and empircal based relationships are still more reliable in some instances.

Now granted, this is for compartment fire and not controlled combustion (which is a better understood science given the inputs are better controlled). But a stove burning cordwood fuel is kind of a mix of those disciplines, given the variability of the fuel type and geometry, variable draft, heat loss, etc.

Anyone's head hurt yet?

 

[Whitespider]

Marc,
L-O-L
You posted that just to confuse me… didn’t you? (that’s all I got… L-O-L)

 

[Arbonaut]

I've been reading this thread with some interest, since I'm an engineer with a concentration in thermo/fluids. I like that you're trying to understand how a device works, what it was designed to do and then modify it and use it to suit your needs.

It reminds me of a quote from one of my most favorite movies, Apollo 13; Flight Director Gene Kranz: I don't care what anything was designed to do. I care about what it can do.

The author of your quote misses the mark. Here's the effective version, "I don't care what anything was designed to do or what it can do. I care about what it does."

 

[slowp]

We do, but I'm sure you know more than me!

WE don't out here, and I too have gone on the line. We go back to camp or home horking up major loogies. I quit going to fires because I'd come home half the time with a roaring case of bronchitis.

Oh, the timber crews and loggers tried to wear respirators shortly after Mt St Helens blew up. They had to work in the ash to get the trees prepped and logged. They found that they could not breathe properly with the respirators on if working normally. We have steep slopes and even the most physically fit people huff and puff doing that kind of work. The respirators provided were made for less strenuous activity. So, they were not used. But you live in Iowa, and that is a more dangerous place!

Can you huff and puff for hours with an up to date respirator? Can you work long shifts with it on? Long being 16 to 18 hours? Those were normal hours when I went on crews. We put in some 30+ hour shifts on initial attack. Crews aren't supposed to do that anymore.

The same goes for fire fighting in our woods. We did and they still do, carry fire shelters which we called Shake And Bakes. I think they'd get in trouble using that term now.

 

[Marc]

The author of your quote misses the mark. Here's the effective version, "I don't care what anything was designed to do or what it can do. I care about what it does."

Well, in the context of the quote what he said was very apropos. Gene Kranz was scolding a pair of Grumman engineers. The flight team wanted to use the engine on the LEM to do a course correction burn, and the Grumman engineers wanted to cover their arses so they wouldn't tell him whether they though the engine would light off in those conditions. They kept repeating that the LEM was designed to land on the moon. Kranz was trying to stress that he understood what it was designed for and that wasn't his concern. Kranz: "Well gentlemen, unfortunately, we're not landing on the moon, are we."

PS If you ever get a chance to hear the real Gene Kranz do a talk, go. He's an awesome dude. "Tough. Competent."

I think I idolize him because he made engineering go from taped glasses and slide rules to being cool, and pushing boundaries, both technological and human.