Optimizing a crappy stove...

[Saunamonger]

So I'm in the process of building my first sauna and when it came time to buy a stove, I opted for the cheapest one I could find that would fit in the sauna - a Vogelzang BX26E. From what I've read on this forum (unfortunately, AFTER I'd purchased and burned once in it), this particular stove is "the clown car of woodstoves." This makes me sad, as I paid 300 for it. Obviously, that's a lot more than it's listed for on the internet, but the cost of shipping a stove to Alaska is around 300 by itself.

So, here I am, with a sh*tty stove. I need to figure out how to make it burn hot. I've realized from my first burn session and some reading (again, mostly here) that the fuel I was using was less than optimal for heat output (green splits and building scraps). I found some seasoned spruce and burned again, with better results, but FAR from satisfactory. I have some work still to do on the building itself, trim and a bit of insulation and draft stoppage - but the stove itself should still be putting out enough heat to feel, right? The thermometer on the side of the stove never got above 400F, even when burning stacks of seasoned kindling.

Any thoughts, suggestions? Telling me to buy a new stove is NOT helpful. I'm not made out of money, and I already realize the mistake I made with this purchase. The question at hand is how to make the best out of what I've got.

I've read a little bit about stack robbers, but they seem a bit sketchy from the reviews I've read. Has anyone had any positive experiences with them, if so would you care to recommend a model?

Thanks in advance.

 

[Corey]

oops - hit the submit button instead of 'thread view'

 

[EddyKilowatt]

What's your chimney setup? Length, diameter, elbows, insulation? Good draft is second only to dry wood in the ability to get heat out of a wood stove. I don't think you want to be thinking stack robber until you have hot fire in a hot stove and are sending hot exhaust up the chimney.

Eddy

 

[Corey]

You don't say how you're burning, but it would be typical to run the stove 'wide open' in an attempt to get the most heat possible. However, excess air will actually cool the stove off and cause the flue gasses to flow through so fast they don't have time to transfer much heat. You will generally find once the wood is fully on fire, closing the damper some will cut the excess air and make the stove HOTTER. The more you close, the hotter the stove will get - to the point where the air starts to limit the amount of wood which can burn, then the stove will start to cool again. If you don't already have a damper in the stove pipe, you might consider installing one - as those stoves are fairly leaky, you might get better control of the air with a damper versus any air control on the stove.

So the short answers (some of which you're already doing) are:

Dry, seasoned wood
Small splits instead of large logs
Optimum (not maximum) airflow
Maximize insulation in the building

 

[moondoggy]

that stove, should run hot by itself, I'd be worried about it running away....and I would not run IT wide open for long.
Pine- seasoned - still is not the highest BTU wood, it is a soft wood. hardwoods put out more heat.
400 is nothing to shrug off, still decent and depending on heating area, within the hour should be quite warming, however with your scraps and a roaring blaze,
a lot of heat may be going up the flue.. is there any type of damper?
as i mentioned earlier also, running with the air intake wide open, on an already established blaze is just helping the heat fly up the flue.
you may find as you limit the primary air temps incease.



edit
damn it, i type to slow...
everything cozy said above..he just said it better.

 

[drewboy]

I ran that stove in my house the first season that I burned (I hadn't heard of Hearth.com at that time) and my major issue with the boxwood
stove was keeping the fire under control. Even with a damper in the pipe and added door gaskets - I just couldn't seem to keep the temp. at a
manageable level every time I burned... A cool fire was not my issue, a controlled fire was.
I'm not trying to damn your purchase, just sharing my personal exp. with that partcular stove.
I think with some dry, small hardwood splits on hot coals and your sauna should be Hotter than Hades.

 

[EatenByLimestone]

Can you get afold of anypallet wood or scrap 2X from a construction site? It is dry and can get the fire going well for your other wood.

Matt

 

[Saunamonger]

As far as my setup, I have the stove connected to two four-foot sections of 6" double-walled insulated pipe, straight up out the roof. I can see the draft going, so I'm thinking that maybe some of you were right when you said burning it wide open was the problem - the draft is so strong it's sucking the heat right out the top. The only time I managed to get a decent heat output was when i burned the crate it came in. That had flames peeking out of the chimney cap, but only lasted for maybe 5 minutes.

I do in fact have a damper. I guess a few more burns with better wood and experimenting with the air control will help me figure it out.

I'll see about getting a hold of some pallets - I know a few warehouses give them away.

I'll update this after another burn.

Thanks a ton for all the replies.

 

[KeithO]

So the total stack height is 8 ft ? Or is there some stove pipe inside the building which needs to be added to the overall height ? If you have a chimney less than 14-16 ft high, you would have low draft and that could be part of the reason the stove will not burn hot.

 

[Saunamonger]

So the total stack height is 8 ft ? Or is there some stove pipe inside the building which needs to be added to the overall height ? If you have a chimney less than 14-16 ft high, you would have low draft and that could be part of the reason the stove will not burn hot.

The stack is only 8 feet, yes.

I'm a little disappointed that the salesman who sold me the chimney didn't mention anything like that. I told him I'd never installed a woodstove before and had no idea what I was doing. He also didn't mention a spark arrestor, something I'm a bit interested in given the amount I've seen coming out of the chimney.

 

[begreen]

You can't expect the salesperson to tell you how to install the stove. This is what manuals are for. The manual states that the stove needs 11 ft minimum stack (fig. 5). Is the stove on a proper hearth and are the manual's defined clearances are respected?

As for putting a stack robber on this stove, I wouldn't do that. Something about putting lipstick on a pig comes to mind. IMHO, putting this stove without an outside air supply in a tightly confined area like a sauna is nuts. Where is the oxygen to supply the fire supposed to come from? How about the humans in the same space? Are they to compete for air supply?

Sorry to be harsh, but this one has Darwin award potential.

 

[eernest4]

sauna guy,

If I was stuck with that stove & trying to get it to preform, I would at the very least,
try to give myself a chance by putting two stove thermometers on the stove, one -- the stack thermometer is placed 18 inches above the stove collar on the stack & since you used stainless steel insulated double wall stack pipe ,you will need the kind of thermometer that
has a probe & will have to drill a (probably 1/4 inch but check the directions that come with the thermometer) and the other thermometer is the magnetic stick on for the stove top.

Then at least, you can compair the stove top temp to the stack temp & observe what settings of the stove do what to the stack temp and the stove top temp and opperate your stove accordingly to the temps that you see.

This has been a huge great help to me, once I learned what the temps meant & how my stove responds to the different controls that it has. Another thing to check is how much smoke is comming out the stack. You don't want to opperate the stove so that it smokes out the neighborhood, that is, if you have neighbors, at all.

It occurs to me that the magic heat fan does not need to turn on until the stove has gotten hot
enough. This is just a matter of plugging in or unplugging the magic heat heat exchanger.

I realize that the MH has a thermostat that turns the fan on & off but it(the mh thremo) does not take into consideration your short chimney & the need to get it really hot for adiquate draft.

May suggestion was to leave the fan off until you are sure that the fire has the chimmney good & hot & then turn on the MH fan & start taking heat out. When the fire dies down ,unplug the MH fan so that the stove can have adiquate draft for the end of the fire.

It will be your job to determine when to turn the fan off & on manually. You can put a switch opperated duplex receptical or an in line switch in the fan electric wire (in line- line cord switch).
Either way, this will be easier than repeated plugging in & unplugging, the line cord all year long.

If you don't know anything about electric wiring, buy a book at the hardware store for home owners wiring or get the national electrical wiring code book. Both lowes & home depot stock these books , as well as your local hardware store or ask your friend if he is handy with electrical.

Maybe some one in your area can tell you about stove thermometers, if you feel that you need more encouragement to buy them.

I bought the magnetic one first ,just on advise that I got here & I soon perceived that I could do a better job with 2 thermometers , & so I bought a second one & have never regretted it for even a second & have been very happy with the degree of extra control that they allowd me.

I knew what my fire was running like .all the time , because of the two thermometers.

Now I would not dream of opperating a wood stove without them.

 

[Saunamonger]

BeGreen: I bought the piping from a heating and plumbing contractor, and specifically told them what I was doing. They assured me that what I had bought was sufficient for what I was doing. I'm not an idiot, just inexperienced.

I've built a heat shield using 24ga galvanized sheet metal and durock cement board, with a 1.5" airspace between it and the wall. My clearances are about 6 inches from the heat shield. The stove is in the corner, with both walls and the floor using the same type of heat shield. It seems more than adequate. I've had a contractor friend take a look at it and he assured me it was sufficient. The air intakes are going to be behind/next to the stove, just off the edge of the heat shield, down by the floor.

A woodstove in a sauna is not an original idea, I assure you. I've just never had to figure out all the details on my own. Which is why I'm here, obviously.

It occurs to me that adding the minimum of 12 inches of single-walled pipe to the stove, in order to attach the MH heat extractor, would extend the pipe by 2'. Another 12" on top of the heat extractor would put it at 11' chimney. Since the single-walled pipe is sold in 2' segments at the local shop, this sounds ideal. I'm still not convinced I need to shell out for an extractor, but it's an idea. I suppose I do need to increase the height of the stack, at the very least.

So, if I'm going to extend the pipe with a single-walled stack, I feel like I need to extend the heat shield as well. Currently it is 4x4 on each wall. The stove sits an inch or two over two feet high. That would put 2' of uninsulated pipe within about 10" of the wall. So my next question is: would a product like this one: (broken link removed to http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId;=-1&catalogId=10053&productId=100052556&N=10000003+90186+503272+1643)

serve as any kind of decent heat shield? Perhaps with durock behind it?

As for the stack thermometer, I'll absolutely pick one up. I wasn't sure about drilling a hole through the insulated pipe section though. Apparently that's kosher?

 

[EatenByLimestone]

I think you are on the right track adding singlewall to your chimney, but I would skip the heat exchanger and just add 4 feet to the chimney. The singlewall will radiate heat just fine... How high above the roof are you currently? What is the pitch on the roof? You must be at least 2 feet above anything within 10 feet of the chimney. Go higher than 11 feet. 8 feet to 12 feet is a huge % wise increase in chimney height. Going up a few more feet may solve all your problems.

Watch those clearances.

http://www.vogelzang.com/Manuals/bx26eMnl.htm#1

Your manual states 36" to walls and makes no mention of heat shields. Be careful. Your life is not worth taking shortcuts. Floor joists have been known to combust when shielded with bricks. The heat will dry them out and help them ignite even when the fire is no where near them.

The manual also states that you need to add a brick or sand floor to the stove.

Matt

 

[eernest4]

I believe that I read a post on here last year where the guy had to drill through double walled insulated pipe & install a stack thermometer with a probe but if you are going to use two - 2 ft sections on single wall black stove pipe, just put the two sections of black single wall pipe coming directly out of the stove collar & forget about the extra expense of a probe type thermometer and use another $12.95 magnetic stick on stack thermometer & place it 18 inches above the top of the stove.

That will work just fine as it is the same set up that i have.

So ,two -2 foot sections of black single wall pipe coming directly out of the stove & then transition to double wall insulated to go through the ceiling/roof & you also get a higher chimney/stack to improve your draft.

Make sure that the single wall pipe maintains proper clearance according to heat shield /stove instalation instructions.

Single walled black stove pipe will give off a LOT OF HEAT , so take care.
I get my single walled pipe up to 800 degrees briefly , every time I lite up my stove, when I am trying to char off the wood & heat the stove up quickly to initiate secondary burn to prevent a smokey chimney.

Then, the stove top temp goes to 600 or 700 deg while the stack temp drops down to 400 deg.

That indicates a great secondary burn, where the smoke is being burned up inside the stove as fuel & what that means is using 4 cord of wood per winter instead of 10 or 12 cords per winter
as I used to burn up before I converted my stove to secondary burn.

Your stove is primary burn only , so you should be happy (or will have to be happy) with a 400 to 450 deg stack temp and a 400 to 450 stove top temp as that is about all that you can expect from a primary burn only stove.

You might be able to get it up to 500 or 550 deg but keep in mind that your stove is cast iron with a much lower melting temp than a 1/4 inch thick steel stove like mine
so don't push it to the very edge of the envelope because its not worth it if something goes wrong. Read your owners manuel, they know your stove much better than I.

If you want to know more about secondary burn & all the wood it can save you (about 2/3 of every cord that you burn is just wasted as "unburned smoke up the chimney" by your inefficient stove) as any secondary burn stove will give the same heat you get from a full cord of wood by burning only 1/3 of a cord & burning up a lot of smoke as fuel to get extra "free"heat. (2/3 more, nearly) one load of wood in a secondary burn stove equals the heat output of 3 loads of wood in a primary burn only stove.

FOR A SECONDARY BURN STOVE "SMOKE IS FUEL" TO BE BURNED & CONVERTED TO USABLE HEAT to make the stove top hotter.


To learn more, click on HEARTH WIKI ---- at the upper right hand corner, above at top of page.

This will bring you to the Hearth wiki page, NOW look on the left hand side---You will have to scroll down or up and see a list in blue type & click on wiki titles list.

This will bring you to a list of titles of wiki articles , about 100 of them, & you can click on any article you like, NOTE: YOU WILL NEED TO SCROLL DOWN or up to find the articles as for some reason, they do not appear at the top of the page , but rather 3/4ths of the way down. for some reason.


I am not critizing you for buying the stove that you bought, I nearly bought one too, but someone clued me in about secondary burn, just before I almost made the mistake & now, both my stoves are secondary burn models.

I am only sorry that I could not have helped you before you bought that stove.

I do believe that the magic heat will get you 30,000 btu /hour more heat so reread my post about turning the fan on manuelly when the flue pipe gets really hot & turning off the fan , by hand , when the flue pipe starts cooling down.

I may yet install a magic heat on my stove, it was on my to do list but got put on a back burner.

 

[Saunamonger]

EatenByLimestone: I think that I'm going to add the 4' section and see how it works. Currently I'm only barely at 2' above the roof, which has a shallow pitch. The extra 4' should work in my favor for the draft and heating, like you said. i know that heat shields aren't ideal, but 36" clearance in a sauna is simply impossible. As far as safety goes, well, it's an 8x8 room - even if the walls, floor and roof spontaneously ignite, there still won't be much danger of being trapped. That being said, I don't want my investment burning down, so I'm doing what I can to make things work. Trust me, I've seen far more dangerous sauna setups that have been used for years. (Not that that is necessarily a good thing, just sayin' that I am taking reasonable precautions.) I do have fire bricks in the stove, 11 of them. I'm trying to figure out the optimal arrangement. Any advice on that?

eernest4: Yea, I wish I had researched better and made a wiser investment. However, I'm not going to throw more money at another, superior stove. I simply can't. This is, after all, an 8x8 room. I should be able to heat it with this stove. It won't be heating overnight, or for any period longer than 4-5 hours at a time. Also, I'll be attending it near-constantly during that burn time.

Anyone have any input on that reflextix insulation?

 

[Jimbob]

Since the stove is already yours, and it is just being used in a sauna anyway, I would just modify your existing stove to accept outside air.
If you do this, you can seal up your sauna nice and airtight, which will help keep the heat/humidity in, making it feel nice and hot.
Modifying the stove to accept outside air shouldn't be too difficult. Permanantly seal the existing air inlet shut, then make a new inlet on the bottom or rear of the stove with a 3" pipe connected to it and the outside either thru the floor, or the back wall. Install a damper in this pipe (you may have to make one up) and you can use it to control the fire.

Fairly simple, and should solve all your problems. Because this stove isn't going into your house you can modify it however you want.
Hope this helps.

 

[webbie]

Fact is, set up right, that should be a fine sauna stove!