Any true 12 hour burns?

[muleman51]

Does anyone get a true 10-12 hour burn from a gassifier that is actually heating there home? My old Aquatherm maybe burned a lot of wood but it was dependable I didn't worry about it all the time. It just took wood. I'd wake up in the morning with a warm house. I never put wood in it more than 3 times a day and if I filled it full could get 12-18 hours depending on the wood. I don't hear anyone talking like that even with storage. We may be burning less wood but at what expense. Even with 1000 gallon storage this year, I get no peace of mind. Just my thoughts.

 

[henfruit]

i loaded up last night at 8 pm 3 big!!splits 3 rounds .temp over night around 14 no wind. at 630 am i had 150 d water going back to the boiler. i have greenwood 100 in a wood shed boiler room 100 feet from the house going to a forty plate hx to aforcedhot hir system heating about 2500 sq. feet.

 

[Duetech]

At night and 20*f with low wind I get 10 hours with black walnut in my EKO40 heating 1700 s.f. with air exchanger. I don't have storage. At 10 hours I usually only have a few coals left and basically have to rebuild my fire. Wind causes me problems with cold temps and very high winds and I only get 8 hours. When I am home I burn catalpa during the day and the best I can get with that is 6 hours. I can get 11-12 hours with moderate winds and temps at 30-35 with the walnut. I can get 10 hours with red oak at around +5*f but I save the red oak for the hard part of winter as I don't have much of that.

 

[2.beans]

my buddies home built seton w130 will go 24 hours with one load at 20 degress. it has 500 gallon storage and is a new 2500 sqft well insulated house. i load mine 2 times a day with a w130 and a 1000 gallons storage, mine is a new 3600 sqft home. my father inlaws goes twice a day with dry pine and an old 2000 sqft house with a seton w90 and 500 gallon storage. when its warmer obliviously it gets better.mine gets a little worse when temps hit 0. my father inlaw and i load every 12 hours.

 

[taxidermist]

No I dont want a 12hr burn I want a 6-8 hr hot burn to charge storage to 180 then I can go 12 hrs with no burn.

 

[in hot water]

It all depends on the load on the boiler during that period of time. If the building load is 60,000, and the boiler is fired to 60,000....

Adding storage only helps if the boiler has additional "horsepower" to keep up with the load and "shed" some to the storage. Or when the building is below design conditions. I believe ASHRAE has a table to show how often locations are at design condition. That would help determine sizing of the boiler and storage.

Adding storage to boiler that can't keep up at design or near design conditions will not help.

The two BIG unknowns are how much the boiler is actually putting out over a given period of time (ever-changing) And what the load is, which is also constantly changing.

That will always be a challenge with hand fed solid fuel burning appliances. It will take some, maybe a lot of operator interface to keep it in it's sweet spot. As hard as I try and with 20 years of wood burning experience I still get bridging, in-efficient burns, crummy wood, etc. By March I've had enough wood burning to be honest.

The very best solution will be to first lower the load by insulating or reducing infiltration (air leaks)

Or build a smaller more efficient structure

hr

 

[Nofossil]

There is a change in mindset when you run a gasifier with storage. I don't worry about getting long burns, and I don't need them. What I do instead is figure out how many hours of burn time I need, and when I want to start the fire.

For instance, today I'm home so I can start a fire any time I want. My storage will run out about 8:00 tonight, and I'll need about 8 hours of burn time to provide a days worth of heat based on outdoor temperatures.

I'll probably light the boiler around 5:00 or 6:00 this evening. I'll put enough wood in it before I go to bed so that it will burn until 1:00 or 2:00 in the morning. That should carry me until tomorrow evening.

In the old days, I'd have to worry about using big (and maybe even green) logs to make sure that the woodstove was still providing useful heat in the morning. With storage, I don't care at all.

I don't want big logs because they don't burn as efficiently. A short hot fire will give me more heat than the same amount of wood burned slowly.

The only issue I have is that my storage is a bit small for my house. That means that I'm better off if the boiler is running during the coldest part of the day, so storage is used when the heat demand is lower. Fortunately that coincides with 'convenience' in my case.

 

[2.beans]

my buddies home built seton w130 will go 24 hours with one load at 20 degress. it has 500 gallon storage and is a new 2500 sqft well insulated house. i load mine 2 times a day with a w130 and a 1000 gallons storage, mine is a new 3600 sqft home. my father inlaw goes twice a day with dry pine and an old 2000 sqft house with a seton w90 and 500 gallon storage. when its warmer obliviously it gets better.mine gets a little worse when temps hit 0. my father inlaw and i load every 12 hours.

let me reword this,when load at 12 hours theres enough coals to get a fire going with little effort regardless of what my tank temp is.

 

[Duetech]

That's good theory and practicality Nofossil. I have seen you state that before. I hope I have it memorized by the time I get my storage in.

 

[Dave T]

Nofossil,
Have you been on board with tweeking your EKO or did you leave the primarys wide open, I was wondering if you've been tweeking, if your seeing results good or bad??Dave
To answer your question YES I get 12 hour burns but I idle a lot..

 

[henfruit]

not burning 24/7 would take away form the charm of not seeing and smelling that little wisp of smoke curling off into no where. kinda like living on the ocean and not smelling the salt air.

 

[Nofossil]

Nofossil,
Have you been on board with tweeking your EKO or did you leave the primarys wide open, I was wondering if you've been tweeking, if your seeing results good or bad??Dave
To answer your question YES I get 12 hour burns but I idle a lot..

I've been tweaking - I have the primaries at 9mm now. I'm not quite happy with the results yet. The burn seems clean, but I'm getting mini-explosions in my primary chamber under some conditions.

 

[Jim Post]

I can occasionally get a 12 hour burn if I misjudge the weather forecast and load too much wood for conditions. Last night I loaded at 10 pm and didn't reload until 9:30 this morning. I tend to avoid relighting fires and strive for just in time reloading. The outdoor temps were rising overnight in front some freezing rain that is just starting to fall. Tomorrow the temps are headed back below zero so I took advantage today and brought in another weeks supply from my outdoor storage.

 

[Tree farmer]

Running with no storage I am quite happy with my burn times. The record has been 14 hours but temps were in the high 30's that day, but on average I can go twelve hours no problem and still have a good bed of coals and boiler is still above 160. Yellow and black birch give me the best burn times but I have to mix in red maple as well. On the weekends I try to burn some hemlock and pine because I have it. The boiler not only allows a 12 hour burn time but keeps my house at 70 both up and downstairs, the old wood stove couldn't even begin to compete with that. So far this has met all my expectations and then some.

 

[heaterman]

Does anyone get a true 10-12 hour burn from a gassifier that is actually heating there home? My old Aquatherm maybe burned a lot of wood but it was dependable I didn't worry about it all the time. It just took wood. I'd wake up in the morning with a warm house. I never put wood in it more than 3 times a day and if I filled it full could get 12-18 hours depending on the wood. I don't hear anyone talking like that even with storage. We may be burning less wood but at what expense. Even with 1000 gallon storage this year, I get no peace of mind. Just my thoughts.

Slight difference in terminology: Don't confuse a time period in which a wood burner burns, then smolders, burns then smolders, burns then smolders ......for a period of 12+ hours, with getting a 12 hour burn time.

Gasifiers are at their best when they are running at full burn. Actually, any wood burner is at it's best under those conditions. How do you think Garn gets overall efficiency in the 75 to 85% range. They set their unit up to burn all the wood in one shot and store the heat. Why do you think efficiency is so dismal (28-45%) in a typical OWB? The short answer is that the fire is allowed to smolder.

Storage needed is dictated by two main things.

1. The heating load of the structure and.........

2. The wishes of the operator as far as how often he would like to tend the fire.

Of course the wood burner has to have the output in the first place. A common mistake I see is that people size their boiler to the demand of the house and forget to add the output requirement needed to charge their storage at the same time.

Hope at least some of that made sense. It's been a loooong week and I may not be fully functional at this point.

 

[heaterman]

At night and 20*f with low wind I get 10 hours with black walnut in my EKO40 heating 1700 s.f. with air exchanger. I don't have storage. At 10 hours I usually only have a few coals left and basically have to rebuild my fire. Wind causes me problems with cold temps and very high winds and I only get 8 hours. When I am home I burn catalpa during the day and the best I can get with that is 6 hours. I can get 11-12 hours with moderate winds and temps at 30-35 with the walnut. I can get 10 hours with red oak at around +5*f but I save the red oak for the hard part of winter as I don't have much of that.

BLACK WALNUT???? Oh the humanity

 

[muleman51]

Heaterman you are correct, I am pretty sure my problem is that I need all the output I can get for the house and just can't get ahead of the storage. I need to change boilers but have to find a home for my Adobe first. Although if I could just recoup the heat that come off the front of my boiler I would have plenty.

 

[eco-one]

Does anyone get a true 10-12 hour burn from a gassifier that is actually heating there home? My old Aquatherm maybe burned a lot of wood but it was dependable I didn't worry about it all the time. It just took wood. I'd wake up in the morning with a warm house. I never put wood in it more than 3 times a day and if I filled it full could get 12-18 hours depending on the wood. I don't hear anyone talking like that even with storage. We may be burning less wood but at what expense. Even with 1000 gallon storage this year, I get no peace of mind. Just my thoughts.

Hello sir aqua-therm owner! have you ever looked into the retre fit kit for your aqua-therm it reduces smoke alot even on shut down it also has a faster recovery and higher btu output with the retro fit kit it is also meets the .60 EPA requierments.they have tested this unit for over 3 yrs now with no problems

 

[rickh1001]

muleman,

I have an EKO 60 with 500 gal. However, I have an exceptionally large heat load, with two homes, one of them being a large converted barn, half of which has 13' ceilings, plus several thousand square feet of attached building that we used to have our business in. So except in warmer weather, such as 25F+, I am using much of the heat that is produced. Based on average wood consumption I have been tracking since October, I am averaging an output of 50K BTU/hr in Oct, up to 80K BTU/hr through December. So my heat storage capacity of about 83K BTU for the 500 gal tank will carry me only about an hour or two at best in the coldest weather. The boiler and storage are in the basement, so there is very little wasted heat. Given that situation, I pretty much run the EKO 24/7. I have found this works the best, and I maintain a deep bed of coals. When I let the fire run out, it takes half a day to really get everything back up to temp, and a good hot bed of coals built up again.

In answer to your direct question, burning like that, I find I need to refuel pretty much every 4-6 hours. Much longer than that, and I have used up most of the embers, and have to start the climb back up again. So I need to run mine more like a conventional wood furnace, in terms of feeding it wood. In my situation, even 2,000 gal of storage would only give me 4-6 hours of heat, which would help me extend heat between burns, but I would have to relight the fire each time. I have found it easier to just keep the fire going more or less continuously, even if I feed it smaller loads of wood. It still gasifies beautifully though, and as long as I have the coals, I get a clean blue flame, so I am getting the efficiency. We just have a dogonne big structure though, and it uses a lot of BTU's. We are on track to come in at burning 10-11 full cords of wood for this winter. Sounds like a lot of wood, but it replaces a lot of oil as well! We have used only a few gallons of oil so far, and only when I was too lazy to keep the beast fed properly, and decided to let the oil burners run overnight.

 

[slowzuki]

My Jetstream is rated at 120 kBtu but there are a few folks I've heard of that run it without storage to heat old farmhouses. Every 4 hours it needs loaded when using hardwood. Every 2.5 on softwood.

I'm still heating with a wood stove for a few reasons and its every 3 hours. Makes for a tired me.

 

[warm in VT]

I typically am running 12 hours with half a load still left. I can run 24 hours and be down to embers with temps in the single digits to low teens. Heating 2500 sq ft and DHW and have used almost 3 cords since Oct. 1 and not a drop of oil. Contrary to popular belief, there is no smoke to speak of and no idling. It is either running full out with fans or shut down completely until the fans kick on the next time.

 

[henfruit]

how can you no idling? when you said it shuts down completly. one in the same i think?

 

[tuolumne]

My Eko-40 is sized for the storage I wanted, not the house (<60,000 btu/hr). I am very close to having the 1000 gallons up and running. I have welded on the threaded fittings without blowing myself up, and I have a few microscopic holes in the welds to deal with. What I find is that the boiler can idle too long with my low heat load and then it fails to come back on line. I often go down in the morning and find the FUEL message and the boiler is still mostly full of wood. Fortunately, the house will still be at 70 degrees...hooray for high density foam insulation. I've tweeked the settings to get efficient burns, so I look forward to just charging the tanks and avoiding the idleing problems. When the temperature is at zero or below, the boiler will usually have coals in the morning...typically around 10 hours from loading. There are so many variables involved. I still can't help going downstairs in the middle of the night to peak at the temperature gage (the baby had me up anyway, I'm not an addict!) Yes, my wife's hot shower is that important to me.

 

[warm in VT]

To me, idling means it is still burning but at a slower speed. Like a car sitting at idle vs. driving along. The car can't be idling and off at the same time..... The boiler is the same way. Once it reaches the set temp it shuts off. Fans go off, air source is shut down completely and stops burning. When the low temp is reached the fans start again rekindling the fire from the coals (the reason it is important to use hardwood for a good coal bed) and relighting the fire. This is why people have stuck paper clips in the air tubes during the shoulder seasons when the shut down time is long enough for the fire to go out completely, then I would agree it is closer to an idle because there is a breath of air sneaking through the air tube to keep the coals alive around the nozzle but not enough to burn. I hope this helps so people better understand how the newer system works.

 

[koda]

Hi all,

I am new here but am finding a lot of good information. Anyway to the original question, I have an Aqua-therm 275 unsheltered OWB and I routinely get at least a 12 hour burn. From +30 F to -20 F. I heat approximately 3500 sf with baseboard heat. I run my stove on 175 degree water and fill it at night at about 8pm and then again in the morning at 9-10 am.