Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: ssr on December 04, 2011, 07:59:27 PM
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I GOT A OWB IVE BUILT MY SELF.THE PROBLEM IM HAVING IS THAT WHEN I CLOSE THE DOOR THE FIRE GOES DOWN TO LOW TO ROAR LIKE I NEED IT.I GOT A DAYTON BLOWER ON THE DOOR I THINK IT IS 130 CFM . THE CHIMENY IS 7 INCH OD.ITS LIKE IT CANT DRAW.BUT WITH THE FAN ON HIGH IT WILL BLOW OUT BIG EMBERS OUT THE TOP OF THE STACK.BUT THE FIRE WONT RAGE UNTIL I CRACK THE DOOR.ITS ALMOST LIKE IT WANTS MORE AIR. ANY IDEAS
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where are you blowing the air..perhaps you need to difuse the air into a wider stram and aim it into your coal bed?
how big is your firebox? how is your chimney inserted into the fire box and where is it positioned compared to the door?
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THE AIR COMES IN UNDER THE GRATES ON THE COALS.I TRIED TO REDIRECT IT TO BLOW ON THE WOOD THAT DIDN'T WORK FOR ME.THE CHIMENY IS LOCATED TOWARDS THE BACK OF THE FIRE BOX ON TOP ABOUT 10 INCHES FROM END. IT COMES DOWN INSIDE THE FIRE BOX ABOUT 14 INCHES.I PUT A PLATE UNDER THE CHIMNEY TO TRY AND KEEP THE EMBERS FROM BLOWING OUT THE TOP.IT HELPED A LITTLE. I RAISED THE CHIMNEY 6 MORE FT. THAT DIDNT SEEM TO HELP MUCH.I THOUGHT IF YOU HAD A FAN ON IT THE CHIMNEY WOULD NOT NEED TO BE THAT LONG,ITS 10FT OUT OF THE ROOF.THE FIRE BOX IS 30''ROUND AND 40'' LONG
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your wood dry and perhaps try smaller pieces so there is more edges to burn. i think my blower is 150 CFM but 130 should get things going. plus, my stove roars more when the door is open as well but a lot of that is going up the stack when the soor is open.
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IT JUST SEAMS IT TAKES A LONG TIME FOR THE WATER TO HEAT UP.AND THE FAN RUNS LONG TIMES AND REALLY USES THE WOOD.THE EMBERS OUT THE CHIMENY WORRY ME IM RIGHT BY A OPEN FIELD. THANKS FOR THE INFO
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Is your fan taking fresh air into the firebox?
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you built your stove yourself you say. and the water seems to take a long time to heat up? i would say after you have lit your stove for the first time and your water has reached its set point and the fan shuts off, then when it cools to your low setting and the fan comes on i would make a guess that most folks stoves would have the fan run 10 to 15 minutes to reheat the water...unless you have very badly insulated underground pipes that are causing severe heat loss. perhaps you could elaberate on just how your system is constucted and piped to the home and what all you are heating?
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THE FAN IS TAKING IN FRESH OUTSIDE AIR.I'M JUST TALKING ABOUT THE BOILER ITS SELF WITHOUT TURNING THE PUMPS ON.IM HEATING A CONCRETE FLOOR 40X60 SHOP FLOOR.IT JUST SEEMS THAT THE BOILER WILL GO THROUGH ALOT OF WOOD TO GET IT UP TO TEMP JUST SITTING THERE.I NEED TO FIND OUT A WAY TO GET THE FIRE TO RIP WITH THE DOOR CLOSED.IVE TRIED TO REDIRECT THE FAN AIR IN DIFFRENT DIRECTIONS ALL AROUND THE BOILER BUT IT SEEMS TO WORK THE BEST BLOWING FROM UNDERNEATH THE WOOD. MAYBE I SHOULD GET SOME HEDGE OR MIX WITH COAL?
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ssr when i fire my stove for the first time in teh fall it may take 30 to 40 minues to get to the high setting but after that it takes 10 or 15 minutes to go from low to high
no matter what you have heard you cant (shouldn't) burn wet wood (freshly cut trees) and you say you are heating a 40 by 60 shop floor, how many loops in your floor (i mean how many seperate lenghts of pipe) each loop should be no longer than say..300 feet and is your shop floor insulated under the concrete
also you might try (temporarily) blocking your chimney off some, if you say the embers are being forced up the chimney than perhaps yoru draw is so strong it is sucking the best part of your fire up the chimney and out and when you open the door you are actually allowing the fire to now draw air and feed the areas of the fire that the chimney cant oull from as it is sucking in a direct line from your blower? (jsut something to try)
i think you may have enough air being supplied from your blower but the draw on the chimney is so great it is sucking too much heat away. perhaps set a piece of plate over part of your chimney as a test?
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THANKS .THE LOOPS IN THE FLOOR ARE 250 FT LONG IVE OR TAKE 10 FOOT ON EACH.THER IS INSULATION UDER THEM. AND ON THE PIPES NOW.
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Is it possible that you could be forcing too much air into the firebox? The embers blowing out the chimney makes me curious about that.
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How big is the opening between the fan and firebox and how long?
Do you have any pictures of how it is setup?
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Posted by: mcarter
« on: Today at 09:23:01 PM » Insert Quote
Is it possible that you could be forcing too much air into the firebox? The embers blowing out the chimney makes me curious about that.
I wondered the same thing
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i thought that i was forcing to much air in it also .but if i turn the fan down the fire wont burn very good at all.the opening in the door where the fan comes out is 3''x5'' rectangular.it is a squiral fan from dayton.i put a reostat on the fan so i could turn it up and down.i can urn it down to calm the embers down but the fire wont burn good at all.
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So you have a 3x5" channel into the ash drawer? Is it straight? Is there any chance the air is going to the chimney and passing the fire?
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its just a 3x5 rectangle hole in the door blowing under the fire.i had a striaght tube on it,but it didnt seem to help.
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Did you ever figure out any of the other things? I remember you were on a couple weeks ago and
Couldn't get any heat out of it.
If your fire burns better with the door open it's not getting
Enough air in the right place to give you a good burn.
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Pictures of your setup may help you get some good advice from the experienced fellows on this forum. I hope you get it figured out, that must be frustrating.
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SSR FIRST WELCOME to the sight the way it sounds is the desigh is like a shaver my stove is blowing sparkes out the stack to i have a 145cfm fan , but what i found out is shaver has only a 75 cfm fan although like there stove the blower is on the back so it sounds as if your stove is blowing straight in and up the stack , mine blows to the front of the stove so the air has to come all the way back then back up the stack , do you have a flapper over the blower opening as to shut it down when not running ,, at the worst like i thought if mine did not work out you could could cut the stack off to all most in side top then weld a plate from the back comming to the front this would bee like a would master stove
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i think your chimney is to long and your air under the grates is your problem.1st air under grates is probably meeting cloged ash and cant get to coals.i would also try to make a nozzle like manifold for air that blows 4 to 5 '' above grates where the coal bed is.the chimney being that long is sucking out the heat .shortning chimney in firebox will make it worst as heat will flow up and out to fast. your chimney being 14'' in firebox is ok but could be longer.with that much cfm from fan .
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the chimy is just like shaver and dose work but i think the air comming from the front going to the back then straight up the stack what i said about cutting the stack and adding another plat would be just like woodmaster stove
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The air needs to be Under the fire for the most efficient burn...
If your grates are plugged rake it around a little, but IF that were the case the air couldn't get to the chimney to roar out anyway.
You really need to get us some pictures on here so we can be of more help, sounds like this project has been trouble from the start, maybe with pics we can be more help
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this is what i was thinking dont you just love pict even if they are bad ;)
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this is the though
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this is the fan mount on the front door
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here is door opening and fire box.
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funny i can build a 6 second twin turbo malibu shaped like a box,but i cant get a fire blazing in my boiler.aint life strange
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Is there grate directly under the chimney? If so put a plate over it. The air is probably blowing straight under the wood and right up the chimney.
To test it you could just let it fill with ashes in the back and keep it packed all the way up to the grate at least 16" from the back.
Most boilers that blow the air under the grate have the fan at the back so it is blowing past the chimney not directly up it.
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What do you guys think based on the pics? Does anyone see anything tharpt jumps out at them?
In regards to a tall chimey, there are members here with like15-20ft chimneys and they make em work fine, only thing I've ever saw a tall chimney hurt was make a small air leak a bigger problem
If your air is blowing in under the grates that's good, I assume you stir it around some so it dont get plugged up, that could cause that if it was totally clogged in the front and only open directly under the chimney...
Natures comfort has the drop chimey like yours that I'm familiar with. There air enters directly under the chimney and is allows to come up through only 3 slots, it works. So I dont know
Your firebox material looks really thick but you said it's only 1/4".
As far as the fire getting hotter when u open the door does tell us it needs air and that your air is going to the wrong place, I'd check to see if your grates are clogged
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Yup, I think rsi is right, the plate of steel would be the fastest thing to try
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i put plate on top of the grate under the chimeny already to try that still didn't make any diffrence for me.i tried plate all the way to the back and left a gap at the back for air to swirl.didn't work for me either.i tried blocking off some of the chimeny on top didn't work for me neither.ive almost pulled my hair out trying things.all i know when i open the door it rips.i do think it needs more air,or the aie redirected .from rear to front
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Hmmmm..... The plate made no difference? I donno...
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Did the plate seal fairly well?
I would try packing the back half full of ashes under the grate and see what that does. You need to deflect the air up into the wood. It doesn't need to be at the back because it is traveling that way to get to the chimney.
If that doesn't work, try pulling the grate out completely and using without.
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i guess i could try to add on the stack and lower it more.closer to the plate
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Did the plate seal fairly well?
I would try packing the back half full of ashes under the grate and see what that does. You need to deflect the air up into the wood. It doesn't need to be at the back because it is traveling that way to get to the chimney.
If that doesn't work, try pulling the grate out completely and using without.
Maybe to many bars going across???
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I forgot to ask, does the fan opening line up with the part under the grate? If you run the fan with the door open does it feel like it is blowing as much as it should?
It might help lowering the stack. You want the air to not have a direct path to the chimney before it goes through the fire.
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the opening for the fan is under grate level.anyone ever tried to run a pipe with holes in it pointing up under the fire
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What do you have for air shutoff?
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i got this thing insulated every were i can.its packed tight with it.i really spend some time on this project it looks nice but works like sh_t.
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dont give up ssr...it has to work..keep tinkering if you use the ideas offered here and they still dont work..well, you will be one step closer to finding the problem. stick to it
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i dont have a air shut off yet.i cant get it hot enough to shut it off.when i get the boiler hot with no pumps running.then i turn the pumps on.it takes a while for the fan to come back on because its got 350 gal of hot water in it,but when the fan comes back on the fire won't rip enough to get the water temp back up.even if i dont turn on all the valves in the floor heat.i know at start up it just takes a long time to get the water hot,cause i cant get the fire ripping.maybe i should fill it with hedge and coal,and burn it down.
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I DO WANT TO SAY I AM GREATFUL FOR EVERYONES INPUT ALOT OF THE STUFF I HAVE ALREADY TRIED ,ALOT OF US THINK ON THE SAME WAVE LENGTH. I JUST THINK IM MISSING A LITTLE SOMETHING OR A COULPE SOMETHINGS.THANKS TO ALL THE REPLIES SO FAR
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i dont have a air shut off yet.i cant get it hot enough to shut it off.when i get the boiler hot with no pumps running.then i turn the pumps on.it takes a while for the fan to come back on because its got 350 gal of hot water in it,but when the fan comes back on the fire won't rip enough to get the water temp back up.even if i dont turn on all the valves in the floor heat.i know at start up it just takes a long time to get the water hot,cause i cant get the fire ripping.maybe i should fill it with hedge and coal,and burn it down.
Hedge and coal won't burn in it either...... No o2, no heat...
The fan on your stove is kinda like a blower on your race car, more oxygen getting forced in verses natural aspiration, it gives your stove more power, more heat, that's what were wanting
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I KNOW I WAS JUST KIDDING.BUT I DID THINK ABOUT A BIGGER FAN THAT WOULD MOVE MORE VOLUME OF AIR AT A LOWER SPEED.IT SEEMS LIKE IM PRESSUREING THE BOILER WITH THIS FAN.IF I HAD A BIGGER INLET ON THE FAN THAT MIGHT HELP.I WOULDN'T THINK THAT IT SHOULD TAKE THAT MUCH CFM TO GET GET IT ROARING
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here is something you might consider..i am no expert on this air volume and chimney thing bu there goes....(i may ever try this on my stove asi have an 8 inch flue)
if you made your chimney the same size as your blower inlet do the air may get to the coals?
i know i read somewhere on line that a fire place should have a 6 inch round chimney to allow for good draft and small enough to keep the chimney warm to prevent crosete build up
i wonder if because we are using forced air to feed the fire if we could get by with say a chimney openingn that was just slightly bigger than the blower inlet?
i may throw a piece of plate over my chimney and "choke" it down a bit just to try it this weekend, it may save some wood?
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From my experience low rpm fans dont do well..
The small high rpm ones work well, your getting plenty of air, building pressure, it's just going where it needs to be..
Why I'm not sure yet
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i tried to make the chimney a smaller opening that didnt work either.the fire would just barley burn.not roar sure it will save wood but it wont build the heat i need
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Something I just thought of that isn't likely the problem, are you sure the blower has a 115v motor on it? If it is 230v it will turn way too slow.
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I'm thinking that if he has embers flying out of the chimney, it has plenty of positive air pressure in the box, maybe too much?
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I'm thinking that if he has embers flying out of the chimney, it has plenty of positive air pressure in the box, maybe too much?
But opening the door makes it burn hotter which means it isn't getting enough air. That is what makes me think it is blowing the air right past the fire and up the stack.
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i know it blows alot of air for a little fan.
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Is the grate removable? If blocking under the grate doesn't help I would try taking it right out and see how that works.
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like i said before i put a reostat on the fan motor so i could slow it down or speed it up.that is kinda nice to have but if i slow it down, it does build even less heat
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the grate is removable .you think i should just build the fire on the bottom of the fire box?i havent tried that one
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Maybe some pictures of your setup would give a little more insite to what the problem is.
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have you tried cleaning the box out and starting from scratch, if you do and it rips it will prove that the air under the grate is meeting resistance with the ash,and finding a out somewhere besides the wood coal area.how many fires have you roughly burned so far?
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i have cleaned out the box alot of times and refired it about 9 times changing things with little progress
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firebox
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take the grate out and throw it away.lol see what that does.
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boiler
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about to see what the scrapper will give me for the whole thing.lol
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will trade for a crappy looking one that works good.lol
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the grate is removable .you think i should just build the fire on the bottom of the fire box?i havent tried that one
Yes.
There are a lot of brands that don't have grates at all.
You need to get a coal bed a few inches thick built up when you don't have a grate for it to work good.
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i will try that one tomorrow.cant get the grate out right now . hopefully it will work
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you do have good wood to burn? and your sure that fan is putting out a good flow of air? that fan is rotating the right way?squirril cage was installed from factory in right direction?
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you do have good wood to burn? and your sure that fan is putting out a good flow of air? that fan is rotating the right way?squirril cage was installed from factory in right direction?
was burning oak,running low now.positive the fan is putting out air.
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getting some hedge shortly.but i still need a good air flow no matter what im burning.
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Is the wood green?? If its wet or green it really makes problems 10x worse
On another note.... I'd rather have dry pine as green or wet oak, you lose over half the available btu if Your burning wood that is not properly seasoned
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i think the best thing to try is the idea of removing the grates and just trying the wood without them.
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its a mix now im just about out,the wood coming is seasoned hedge.the wood i had before was seasoned oak and green bs mixed. will the hedge be to much if i load it half full
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In your stove I have no idea, in a stove that shuts down properly and seals the air out it's no big deal but where we haven't seen any consistency on your stove so far I'm not sure what will happen
Did you ever switch the pump from top to bottom?
Also, if it burns correctly and you have no way of shutting all air off to the stove it should boil over in less than an hour and probably look like a geyser
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Is your stack plugged?.. Not sure how high it is...I had a problem last spring..The very top of my stack was pretty much plugged up..Inch thick of creosote and the opening was about the size of a golf ball..Like I said It was at the very top of the stack..Rest of the pipe was clean...When it was plugged up..It didn't matter with forced air etc...That fire would not burn like it should when the door was shut....Almost seemed like it was putting itself out when the door was shut..Not to mentioned..Door gasket was all gooed up....
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i would try dumping some sand or dirt about 12inches back from the door all the way to the top of the fire greate this way the air has to go up through fire first easy test