Hybrid Elm on the Way (on the hearth) Pics

[REF1]

Well, to clarify and not be misrepresented ;-), I certainly never meant to imply companies suggest over-firing. But one man's/stove's over-firing is another's medium burn. Depends on the stove, the fuel, the size of the load, desired cruising temps, etc. Hearthstone recommends a couple hot fast fires a day. This is, after all, your opening quote for Napolean:

Napoleon:
“Remember. it is more efficient to burn medium sized wood, briskly, and
refuel frequently than to load the fireplace with large logs that
result in a smoldering, inefficient fire and dirty glass.

According to the above description of the four Elm owners, such a cycle might be considered inefficient. So, as I stated, a definition of "efficiency" needs to be given.

 

[REF1]

And a line from the specs for PE also represents what I stated about manufacturers recommendations:

• Burn small, intense fires instead of large, slow burning fires when possible
• Learn your appliance’s operating characteristics to obtain optimum performance

I have to say the Elm's operating characteristics are far from inefficient.

 

[Nonprophet]

Maybe you should define "efficiency." To me it means complete burn of fuel. As little as possible wasted. It sounds like the owners you speak of feel the stove burns too fast.

To me, "stove efficiency" is operating the stove properly within specs (i.e no over-firing) while producing a set amount of heat per a set amount of wood. In other words, all things being equal (draft, wood, etc.) stove A could be considered more efficient than stove B if it could keep the same space heated to 75 degrees for 24 hours on x amount of wood when stove B used more wood to maintain the same temperature.

The 4 modern Elm owners I've spoken to are all experienced burners, so I don't think that it's operator error or the quality of wood, though I don't know for sure.

NP

 

[begreen]

Well, to clarify and not be misrepresented ;-), I certainly never meant to imply companies suggest over-firing. But one man's/stove's over-firing is another's medium burn. Depends on the stove, the fuel, the size of the load, desired cruising temps, etc. Hearthstone recommends a couple hot fast fires a day. This is, after all, your opening quote for Napolean:

Napoleon:
“Remember. it is more efficient to burn medium sized wood, briskly, and
refuel frequently than to load the fireplace with large logs that
result in a smoldering, inefficient fire and dirty glass.

According to the above description of the four Elm owners, such a cycle might be considered inefficient. So, as I stated, a definition of "efficiency" needs to be given.

Just suggesting that moderation is usually the guidance. I don't think any of us burns intense short fires with smaller sticks. Well except for masonry stove and kachelofen owners.

 

[REF1]

I guess we need a definition of small sticks, too. My Homestead did much better with smaller splits and branches, rather than bigger ones. Based on the wood I purchased for my first year here, the larger splits he gave me basically filled the firebox at three and small one to make four, and the stove really couldn't handle them save for certain times when the cycle just worked better than at other, most other times. I burned a hot fire every morning with small splits. Couple hours and time to reload.

The season is basically over for me, but with this Elm ... well, it just burns much differently. I have no big chunks of unburned wood left and right in the box in the morning. And each fire lasts much longer than the Homestead even with less wood. So, I fully expect to use alot less wood next year. To me, honestly, I have no idea how these Elm owners can say the stove is not very efficient. Especially when that barrel can take temps higher than most stoves of comparable size. Next to the Homestead, which weighs 85 more pounds in mass, the limit is 600 degrees according to Hearthstone. The Elm can get a whole lot hotter than that.

I'd like to see some of these aforementioned Elm owners post here and explain their situations. But even Steve Slatter will state plainly the new box beam will out perform the Utubes in his stoves. It's all part of his constant advancement in design and function going for the ultimate burn.

 

[REF1]

Well, as I mentioned a few posts back, after some of suggestions and alot of emailing, Steve came up with a very simple, but very effective prototype for an air wash. It's removable, so cleaning out the stove is still easily done, and it also actually increases air flow at the base of the fire for easier starts and a cruising burn cycle.

He just sent me the link for the youtube video, which also shows that crazy box beam in action. I'm gettin' me one a those, Brother. That thing is a monster volatile gas eater! Check that puppy out -

http://www.youtube.com/watch?v=KO-oA245WX8

Ain't burnin' wood fun? And here I am out of state in a motel when it's down to freezing tonight at the house. I could be home burnin' my Elm.

 

[Todd]

Looks like fun tinkering with those stoves. That video looks like the flame is a little out of control even when he shuts her down. Do you think it's because of the air wash? I think it would work better if he could rig the air wash to wash down from the top of the door and have a air tube channel where the air can heat up before washing the glass. I still like lazy slow flame of the cat Elm best.

 

[REF1]

Actually, I've asked him to do a video of the stove during a much slower burn cycle to see how the beam works. Steve says he loves watching the blue flames at the lower settings.

The air intake on the Elm is just a surging thing. When you close that flapper flames really thrust forward, if it is closed too quickly. The way the ash dam reflects air back and out when you close the flapper was the original way the air wash was supposed to work, but it never really performed too well, imho. Basically a hot fire is what kept the glass clean, like many other stoves of similar air intake design.

Being a cast iron ring on the front, I'm not sure what rerouting of air through a cast passage would entail. A new front casting, obviously. Although I don't know if you can cast a tube like that. Which is why the idea of adding a piece to the dam has been the result. Once it's completely refined both as a working unit and cosmetically, I think it'll be the ticket.

If you looked at all the pics at smugmug there were some really interesting tubes he had set up at one time, which looked like it may have employed a top down air wash. I guess he found things that have performed better overall. But I reasoned that in today's field of wood stoves clean glass is a must.

Having watched the beam in action, and watched other types of tubes in action, including my Homestead, I am just knocked out by what that beam does. If the idea is to ignite those gases it sure looks like it just eats them right up. To me that adds up to great efficiency, which is the entire purpose of secondaries.

 

[Battenkiller]

The things he is able to do with this design are truly amazing. Steve is rapidly becoming my wood burning hero. I just may try and pay him a visit.

 

[REF1]

I have family stuff going on up there in June, right near him, and I can't wait to go over and meet him and see what he's into. Have to get my beam and air wash, too.

 

[REF1]

At the Heart, Patio and Barbecue assoc. site I found this quote in a PDF brochure:

WHAT IS RESPONSIBLE WOOD BURNING?
It’s about minimizing the emissions from a
wood fire. Practice responsible wood burning
habits (such as building small hot fires, using ...

No trying to start an argument, of course, but I sure do see alot of that philosophy surrounding modern wood burning practices and EPA stoves. And I wasn't even looking for it. Small, hot fires. Of course they don't define what they mean exactly, but the drift seems pretty obvious. EPA stoves do better with small, hot fires, which can obviously mean faster cycles overall. They aren't as concerned with cycle length, as they are with cycle cleanliness. Matter of fact, I found out the EPA lab test does not test for efficiency. That's another matter altogether for them, and they show that by producing the same numbers throughout their list - 63% for non cat, 72% for cat stoves. Private labs test for manufacturers, or they do their own in house testing.

I just read something about 65% efficiency being a top number because of water content and condensation in firewood and other technical matter admittedly over my head, so all manufacturers numbers greatly higher than 65% can be considered hype.

 

[begreen]

There is a difference between burning efficiency and overall heating efficiency. You can have a stove that burns fuel as well as possible, yet it very poor at releasing the heat into the room. That would be very inefficient, like some inserts without the blower running. Or you can have a stove where one small hot fire heats the house all day. That would be very efficient, like some masonry heaters.

 

[REF1]

Ah, but here is another quote from the HPBA site:

"Why was 75% efficiency selected?

The 75% efficiency was designated by the U.S. Congress in 2005 as part of the Energy Policy Act and was used again for this tax credit. Are biomass stoves installed in new or vacation homes covered by this tax credit?

How is the 75% efficiency requirement determined?

The manufacturer of the stove must provide certification that the product tests for at least a 75% efficiency rating using the lower heating value, i.e., the heat value of a combustion process assuming that none of the water vapor resulting from the process is condensed out, so that its latent heat is not available."

So, the IRS wants to see 75% efficiency rating and only pellet stoves are given a default rating of 78% on the EPA stove list.

This is rather confusing, as well as sticky business. Is the IRS going to check out the lab testing of every manufacturer for every stove they produce and claim is 75% efficient?

 

[begreen]

Lots of ways to rate efficiency, including electrical efficiency if it is using a fan. This gets confusing, but the difference here is combustion efficiency vs thermal efficiency.

 

[REF1]

Okay. Which is the EPA using as the default? Logically the combustion efficiency?

Now if we go back to the above comments on the Elm's efficiency, being the steel stove it is, it certainly creates heat quickly, for heating efficiency. I have experienced long burn times per load, with good whole house penetration. I would really like to know what the four Elm owners mentioned above find less than satisfactory with their stoves within the parameters of "efficiency."

 

[Nonprophet]

Now if we go back to the above comments on the Elm's efficiency, being the steel stove it is, it certainly creates heat quickly, for heating efficiency. I have experienced long burn times per load, with good whole house penetration. I would really like to know what the four Elm owners mentioned above find less than satisfactory with their stoves within the parameters of "efficiency."

I'm not sure why none of the Elm Stove owners I've spoke with are chiming in on this thread. Maybe they don't want to hurt Steve's feelings? Maybe they're too busy? I don't know. What I do know is that all 4 owners of the "modern Elms" I spoke with said they pretty disappointed in the fact that their stoves burn through a good amount of wood.

Are they unique? You bet! Are they gorgeous? Absolutely! Are they a really clever yet simple design? Yep. Do they put out some heat? Yes! All of those things are great.

What I'm concerned with is how much wood I would use heating my home per year with a modified Elm stove vs a more modern and tested EPA II stove. That's why I was asking you about your new Elm hybrid, as that stove should be about the most "efficient" Elm stove out there. I don't want to go through the time and effort to modernize the two older Elms I have now if there's too high a premium (in terms of wood consumption) to use them as daily heaters.

From what I can gather, the folks that I know using modern Elms are saying that they burn about 30-50% more wood with their Elm stove than they did with an equivalent EPA II stove. If you look through various forums and see comments from Elm owners, while there is a loyal following of people who like the old stoves, most people agree that these stoves were never miserly when it came to their need for wood. If memory serves me correctly that's why Elm went out of business in the early 80's because they couldn't (or wouldn't) pass the newer EPA efficiency requirements. It would be interesting to see (if it's not cost prohibitive) if the modern Elms meet today's efficiency standards.

I also agree with you that "stove efficiency" is a somewhat nebulous concept. Often times it is quantified in terms of "grams per hour" of particulate matter a stove produces, i.e. my VC Defiant/Encore is still one of the most "efficient" stoves out there rated at 1.6 grams per hour. Then there's "thermal efficiency," etc.

To me stove "efficiency" means how much wood it will burn to heat a given space. Stove A would be considered "more efficient" than stove B if it burned less wood to heat the same space to the same temperature over a given period of time all other things being equal. And given my limited knowledge about the subject, I'm not sure that there is a direct and/or consistent/verifiable correlation between "grams per hour" of pollution (unburnt smoke) as related to the amount of heat produced by a stove using a specific amount of wood. It would seem to make sense that a 1.6 gram per hour VC stove would burn less wood than a 3.9 grams per hour Lopi Liberty to heat the same space, but in my experience that's simply not always true. Maybe others could chime in with their thoughts on what "stove efficiency" means to them.

NP

 

[REF1]

Yeah, I don't know what to say here. I can only answer for my 15 years with the unit I had, and this new one, which seems to perform the same way. It has worked out much better than my Homestead, all angles considered, so for me, the stove is more than efficient in my book. I thought I was going through more wood than necessary with the Homestead, but again, small firebox, and the soapstone was not the material for my desires in a stove. I had one before and should have known better but my wife loved the look, so ...

I know there were a number of different "modern" Elms, as far as the secondaries Steve employed, and his baffles, etc. He keeps moving forward. Of course, mine has a cat, and as far as I am aware of the history, cat Elms could have easily passed the EPA tests back then. The company folded for a number of reasons, including poor management.

As far as any given stove heating a home, it's always possible to get a stove too small for the job and end up burning more wood than you needing a beefier stove. I originally had a 24" and brought it back to Waterbury for a 36" and it worked great in my house. Compared to the other stoves I had the Elm was easily the best for what I was looking for in a stove.

I haven't looked up the Elms on this forum. I will do that and see what's posted by folks. I do wish the owners you mention would post here. I didn't know they were participants on this forum.

So, did you get your Elms before you contacted these Elm owners?

 

[REF1]

I'm really curious what EPA phase 2 stoves these folks used and why they decided to get Elms to replace them.

 

[begreen]

There have been very few Elms mentioned on the forum, so this is probably not the best place to seek answers about other Elm owner's thoughts. Ideally Steve should host a forum for Elm owners to compare notes and chat about modifications.

 

[REF1]

Actually, I brought that up to him a couple weeks ago.

In doing a search for Elms, tis true. I only found three other threads, going back to 2007, and no negative comments. Some misunderstanding or misinformation about Vermont Iron, but no negative comments about the stoves, so I am somewhat mystified about this.

 

[REF1]

NP, I don't remember if you said you got two stoves to use parts for one final unit, but I would think, depending on what you paid for them, a fixed up Elm would net you more than reselling your current acquisitions if you chose not to keep them. Are they 24 inchers or 18"?

 

[Nonprophet]

I'm really curious what EPA phase 2 stoves these folks used and why they decided to get Elms to replace them.

None of the people I spoke with replaced an existing EPA II stove with an Elm--they either sold a house and the old stove with it and got an Elm for their new home, or, they had a second home where they installed the Elm.


NP

 

[Nonprophet]

There have been very few Elms mentioned on the forum, so this is probably not the best place to seek answers about other Elm owner's thoughts. Ideally Steve should host a forum for Elm owners to compare notes and chat about modifications.

Yes, sorry didn't mean to imply that their were a ton of threads here or Elm reviews on H.com If you do a google search for Elm Stoves (or Vermont Iron Works) you'll come across threads in other forums, i.e. I know there are some threads about them on AS.

NP

 

[Nonprophet]

NP, I don't remember if you said you got two stoves to use parts for one final unit, but I would think, depending on what you paid for them, a fixed up Elm would net you more than reselling your current acquisitions if you chose not to keep them. Are they 24 inchers or 18"?

I have one 24" and one 18". They are both complete and fully functional, a "restoration" would just consist of cleaning them up (some light surface rust on the body and some pitting on the connecting rods) re-gasketing them, and replacing a few cracked bricks. I am interested in modifying them with secondary burn tubes, but only if they'd make good heaters for me--it seems like a fair amount of work and time and effort, though they sure are gorgeous once they're fixed up

NP

 

[REF1]

The U tubes install pretty easily. I think the steel baffle is just four holes and they may align with fixtures already part of the stove. Not sure though. Haven't gotten the box beam yet, but it also looks pretty easy to install. The main thing is just drilling the holes in the back of the stove, so a big bit would be necessary. I think Steve mentioned on one of his vids that he starts a small pilot hole in the cast iron first, and he just uses regular steel bits, which surprised me.

Man, if I had the stoves I'd modify them in a flash. Are they the Elms with the leaf cook top or the ones with the combustor chamber on top? I reckon they're called Clean Air Elm and Wildfire Elm now.

I guess if you fixed up one, say the 18 first and used it awhile you would know whether to fix up the 24 as well. And if you didn't want to do both tubes and beam, I'd get the beam first.