Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: flying53gmc on March 04, 2014, 05:41:11 PM
-
Hello all. I decided a few months ago that I wanted a wood burning furnace and did some research and read all I could on here. A trade came up on craigslist for a very well made home built unit that was modeled after the HOSS furnaces from Tennessee outdoor furnaces. I traded a golf cart for this unit that was only in service 18 months and was hooked up when I went to view it. The owner was building another for himself. He was heating his 2200 house and 8000 sq ft shops with it. I just heating my house with it now with a water to air heat exchanger in my duct work. the unit is only 35' from my house with a badger 3 speed pump and badger underground insulated pex. I have the boiler temp set at 175. It is eating so much wood i can't keep it fed. I got way too big of a unit and dont know what to do now. I have 2 year old oak and it seems to be eating over almost 2 ricks a week and Im only heating a 2200 sq ft house with it. Not sure you guys can help but I just wanted to show everyone my mistake. Oh well.
-
Here is a pic of how big this thing is. I think it holds over 600 gallons.
-
Wow thats a beast, maybe trade with the local mafia? Their always looking for ways to make people disappear.
I'm betting that's your problem, it probably does reasonably well under a full load and a roaring fire, but with little heat load it just smolders too much and probably doesn't run long enough to get everything good and hot when your house does call of heat.
Just me best guess, we have some sharp cookies on this site that I'm sure will chime in.
-
What kind of insulated pipe are you using? is it buried yet?
-
Badger insulated pipe. It is the three wrap and is burried.
-
Lappin the mafia haha. If the guy who built the boiler is going to build himself a new stove maybe ask if he can build it smaller than that one, and see if he will trade that monster back just an idea I know craigs list can be shady. It's worth a shot
-
That chimney cap looks plugged up. Remove that stupid thing and see if a good clean draft helps your burn times.
-
Where the heck is your door rope seal? Geesh
-
There is a channel in the door with some sort of sealing gasket. Its not a rope gasket but it does seal good. I cleaned the chimney cap the other day with no real improvement but I have not tried to burn with it off. I will try that but not holding out much hope. Thanks for the replies. I guess I just wish someone that needed on this size would trade me theirs that is undersized for their application, but not mine. oh well
-
My stove is 228 gallons just heating 1800sq ft ranch and hot water and I've never had a issue. I'd be curious if you are losing a lot of heat from your underground pipe. I'd start by checking your temps from the stove supply line and where that same pipe enters your home.
-
1/2" Firebox
-
That boiler is massive!..Im surprised that the guy who traded you for the golf cart wasn't straight up and honest about that boiler is way to big for your application..600 gallons of water..No wonder your going through the wood.. I heat 1800sq and my boiler holds 60 gallons of water..I think it would be a great boiler for a large warehouse, green houses, apartments that have a large demand for heat/hot water.. But also has a ample supply of wood.. Yeah post it on craigslist/ebay..You never know..Its a big world out there..
-
I'm not blaming him. He told me what he was heating with it and that it would be overkill for my application, but said it would go 14 hours between feedings. I'm not getting that sort of duration. The fabrication on it is very good, just way to big for me.
-
Folks, the gallons ain't the problem
I don't care if it's 1000 gallons, if it was it would just idle for a reallllly long time, then when it recovered it would burn for a longer time, which isn't necessarily a bad thing
-
Those thick fire boxes are hard to transfer heat through.
I have told the story many times about the testing with nature's comfort in 08 where the 3/8 models required 13% more wood to produce same amount of heat, in the half inch box that number is multiplied
-
The HOSS furnaces do have a 1/2" firebox, but this is a home made one that is designed after one. It only has a 1/4" firebox.
-
Folks, the gallons ain't the problem
I don't care if it's 1000 gallons, if it was it would just idle for a reallllly long time, then when it recovered it would burn for a longer time, which isn't necessarily a bad thing
Scott thats my point its the recovery time..I don't see how you can say its not the gallon problem..It takes a lot of energy to reheat a large volume..Is this case of course is a gallon problem..Its wasted unused energy..Who needs 600 gallons to heat a 2200 sq area..
-
I have a way oversized unit for my present use and I'm not having that problem. Do you pack it full or pack it for your needs? I agree the gallons aren't the issue if it was then the fire would just die out between firings. It's likely a transfer problem. Better do some more checking before you give it away.
Don't try this without some long thinking but maybe you could pour some weak mix mortar in the water jacket to lose some of the water volume?
-
im staniding with scott on this one (mostly anyways) there are only som any btu in a rick of wood...if you burn it all at once and store it in the 600 gallons of water then the water will give up that heat as it is needed by the home. if you have 20 gallons of water that water will heat up (and if the furnace is good) the fire will idle down until that 20 gallons has given up all its stored heat until the low water temps casuees the fire to burn again and let out domw more btu to the water..the wood will only last either way until it has given up its btu....all at once..or a little at a time makes no difference...there will be heat loss from the stored water that never reaches the house but the short burns will lose some btu 's as well between getting up to a hot burn and cooling down after a burn...you need to look first at why you are losing the stored btu (if they are being stored) perhaps there are too many going out the stack when burning?..perhaps the stoves insulation is lacking and the stored btu's are leaking into the great outdoors?
-
Yea it's not a gallon issue at all
There is a lot of Taylor stoves around me heating 22-2500 square feet and a lot of them hold 750 gallons
You all are way to caught up in gallons, I've heated with stoves that held 30 gallons or 300, neither was a miracle or a killer..
It's about how well the stove transfers the heat and stores the heat vs just how much water you have
-
Please look into this more as ur stove just being to big is not the issue
-
Garn boilers hold even more water ,,,, 970 plus. The firebox holds a face cord. That is a big stack and there is a lot of standby loss right there, have to look at the overall insulation as well. A typical cast iron House boiler gains 4-7% efficiency or thermal transfer gain from the automatic damper according to the manual charts.
Properly setup and insulated no reason why that beast can't fire once a day to heat even on real cold days.
-
Maybe it is poorly insulated. Does snow stay on the roof or does it melt quickly?
-
I'm in middle TN. We don't get snow to speak of. I'm up for trying anything to make it work. I will measure the temp at the pex to check my heat loss this afternoon.
-
While you are at it check the temps at the stack while the boiler is on and then again when it is off, for the off temp wait about 5 minutes after the burner has shut off, try to measure the exhaust and not the stack, you can do this with a temp probe. I'll take a guess, On cycle 1000 degrees or higher, 5 minutes after it shuts off will be 4-500 degrees, 1/2 hour later with the boiler still off 180 degrees!
-
How well is it insulated is would be one question I would ask, what is behind the tin? How good does it seal up around the door and damper is the other. That is a big door to have no insulation also.
-
I think slim and sprinter, Willie g, all guys who have been around know that this isn't a stove is to big issue
Let's look at it this way. Your heating a small space in a mild climate
The heat that is produced doesn't magically disappear, if you have 600 gallons the heat produced during the burn should be stored inside the water jacket until it's ready to use by your home. Either the stove is extremely poor designed or terribly insulated. To heat 2200 Sq ft in Tennessee should require filling on a stove this size no more than once a day perhaps less if ur home is half way insulated
-
Coming from someone who has a 600+ gallon stove.
1. Check your stack, if it's to large a lot of your heat will be leaving the box before it transfers to water. You may be able to build some sort of baffle.
2. Check the blower if you have one. If it's set to high you will blow the heat out of the box before it transfers to water.
3. Speak with the builder about insulation. If he spent the time to make it look like that I assume he would have spent the extra on insulation.
4. Change burning style. I live in a similar climate and have a similar heat storage 600+ gallons. I use a timer setup before the aquastat.
In burning I've learned the correct amount of time per load. Set the timer to go off at a certain time based on wood. This allows the
aquastat to run while the fire is going and cut off after the given time, keeping your fan from blowing the heat out of your water.
I'm with Scott, the water stored has nothing to do with the efficiency of the stove (Unless it's poorly insulated). If your trying to keep wood in your
stove and run like a smaller gallon stove it would burn much more wood due to idle time. With the setup you are running (Stove to Large) I'd run it
like a batch burn and draw the heat in between burnings (See note #4 above).
-
Im in Middle tn with a Hoss 400 HE with a 400 gallon tank , the weather has been crazy , week ago in the 7o's and then been iced in last 3 days with nothing above freezing ,going to melt today !!
Im with Scott on its not the gallons , if its burning that much wood the heat is going somewhere , either the home or lost enroute underground, I heat 2 large greenhouses that are not insulated at all ( 6 mil plastic) that i keep at 58 degrees, when its at freezing i get about a 8 hour burn time on a load of wood , when its 5 degrees out I get less ,
as suggested id check what the temp is leaving the boiler , check the temp at your heat source at the house and them check the temp on returning to the boiler
wood makes all the difference, while mine will burn anything green and wet it also has a hard time with it maintaining temp with wet wood ,
if you got that unit for a golf cart you got a steal ! . I think your off to a good start and are way ahead of the game with what you have in it It just needs some fine tuning ,there are lots of good people here that will help you out but i don't think you need to give up and get rid of it
post some more details around what your settings are/differential is , but measure that temp at those locations and eliminate the piping underground losing it
I had problems with mine this year with it getting plugged up a bit , i thought it was clean by punching it out and i could run a stick down it and thought it was good , i had to buy a brush and modify it to fit the chimney so it takes 2 brushes to clean mine real good right ,
keep posting and asking the guys here questions, they will help you get to the bottom of it
-
Folks, the gallons ain't the problem
I don't care if it's 1000 gallons, if it was it would just idle for a reallllly long time, then when it recovered it would burn for a longer time, which isn't necessarily a bad thing
Scott thats my point its the recovery time..I don't see how you can say its not the gallon problem..It takes a lot of energy to reheat a large volume..Is this case of course is a gallon problem..Its wasted unused energy..Who needs 600 gallons to heat a 2200 sq area..
What's it matter if it took longer? His home btu requirements are still the same and it's possible it ran more efficient taking it longer to recover
If he produced enough heat to heat 600 gallons that heat should last him a longggg time
-
I guess my question is then..If it's not the gallon thing and there's no such thing as a boiler being too big.. Why do manufactures of the owb offer models with different water capacities.. Why not just build one model and call it good?
-
I guess my question is then..If it's not the gallon thing and there's no such thing as a boiler being too big.. Why do manufactures of the owb offer models with different water capacities.. Why not just build one model and call it good?
Price, folks that could get by with a much smaller one wouldn't want to pay for one that has a much higher capacity.
Gasifiers are a totally different beast and from my understanding being too large is almost worse than being slightly undersized.
-
I guess my question is then..If it's not the gallon thing and there's no such thing as a boiler being too big.. Why do manufactures of the owb offer models with different water capacities.. Why not just build one model and call it good?
Price, marketing, competition, but like I said let's not get caught up on gallons
Let's take a random well respected company that's been on business a long time.
Woodmaster 3300 - holds 105 gallons and is rated to heat 2000 sq ft
Woodmaster 4400 - holds 117 gallons of water and is rated to heat 5000 sq ft
Did those extra 12 gallons of water make that stove capable of heating over 3000 more square feet, I think not
But there can be down sides to over sizing, but to keep from further confusing the topic let's just be clear it's not his problem
over sizing a gasser is a whole other story
-
From the suggestions I'm noting a couple of possible problems. The blower is on the back just like a hoss but the builder of it also but a second blower piggy backed on to the first blower because he said he had trouble getting up to temp. It seems this could be blowing all the heat up the flu, which also may be too large. I am estimating it is around 7x10 but can measure if needed.
-
All you can do is make some changes and test. Recording as much data as you can will help the pro's help you better quicker.
Pipe temps, good idea to label pipes clearly too. Test draft changes, how's that insulation under sheet metal? Firebox ceiling design? Fire box dimensions? Pics always help
-
blower piggy backing?
He built the boiler with (2) blowers attached at the same point or seperate locations?
Have you been able to get your stove up to temp 170-180?
Check the temps on your lines per previous requests.
-
I will check line temps this evening. Yes on the one location for 2 blowers. One is blowing into the intake of the other. I have gotten it up to 180 a couple times but it is hard. I work during the day so I load it at 6 am and when I get home at 4 it has burnt everything up
-
I'm not a fan of the elevated grate design. To me it would be hard to build a good coal bed which is probably affecting your burn times.
-
Ummm??? First I would remove the (2) blower setup and make it (1).
Does either of the blowers have a plate to restrict the air coming in?
I'm not sure of a conventional that includes (2) blowers but someone may be familiar with this setup.
If you force to much air into the firebox it will push all of your heat straight out of the flue.
When you get home @ 4pm is the blower still running?
-
Hopefully if your willing to take pics and work with us and do some fabrication we can make this work for you..
It's not going to be one specific thing that fixes it tho, likely a whole slough of 5-10% efficiency increases that take u from disaster to happiness
It's just a matter if the design itself is truly fixable
-
Don't listen to these guys! That thing is JUNK! You'll end up having a stroke or a heart attack worrying about it.
Give me your address and I'll come take it off your hands before it gives you any more trouble. AND, I won't even charge you anything!
You're welcome.
-
HAHA^^^
It is interesting that he was having a hard time getting it up to temperature and you are as well. That means that the heat from the fire is not making it into the water for some reason. Like stated before there are a couple of likely culprits. The fans are likely pushing a lot of the btus right out. The other issue I think is the flue size, what did he use for a diameter? Is it lowered down into the firebox at all? Any restriction to force the heat to stay in longer before it exits? You should also get the stove up to temperature before you start feeding the heat to the house. So fire the stove to 180 and then start heating the home. It is difficult for the stove even though the water jacket is so large to heat returning water and bring the water jacket up to temp at the same time. Once the water jacket is up to temp it is much easier to maintain that temperature as the cool water returns. He did a very nice job on the outer shell. I didn't see anywhere that you talked about how much or what kind of insulation he used. After heating 600 gallons up to 180 you should be able to hold a high temp for a long long time.