I'm building a homemade boiler

[hondaracer2oo4]

Your also likely to get smoke with a conventional and more so with yours because of the extra passes through the water jacket. Not sure what kind of moisture your wood is at but I found that 25-35 percent was the best balance. With a right side up fire f the wood is to dry it will burn up quick, the greener wood slows that process down. The downside to that is more smoke. A good coal bed will do the most to minimize your smoke. But at the end of the day it is a conventional boiler and it is going to smoke.

 

[Fred61]

Bad time of the year to make any determination how to operate your boiler and pine, spruce and poplar are not the correct fuels to be doing it with. Also barometric pressures and moisture laden air have an effect on your burn. I have no doubt that once winter comes these variables will diminish and you'll have it figured out. If there's any dry wood left by then LOL.

 

[warno]

I went to pick up more wood this morning from dad's pile and when I got back the smoke had almost stopped all together and there was a good amount of coals and wood left. I'm guessing I'm getting a bunch of smoke from the semi wet wood I'm trying to burn. I'm trying to do the tarp thing this year to keep the rain and snow off the wood. Next year im hoping to get into a wood shed situation. I bumped up the thermostat in the garage alittle to see if the added heat demand will keep my fire from burning out. I'll check on it again around "getting home from work" time and see what I have in the box.

I also cleaned my heat exchanger out and I got about a hand full of black crumbles from that. Is that an ok amount for burning about a weeks time?

 

[hoverwheel]

Point of curiosity... Or maybe points...

With a run of the mill gas or oil boiler, when the tstat calls for heat, fuel and air flow, burn and produce the heat, then circulated through the radiators.

With a storage system, you run a hot fire until it burns out, or until the storage is up to temperature. When the tstat calls for heat, the radiators draw on the heat in the storage.

With a wood fired boiler without storage, that tstat is doing what? Controlling airflow to the firebox? That raises the temp on the coolant in the system, flows/pumped to the radiators.

Is this pretty close? Long term, down the line, I'm interested in setting up a wood fired, storage based system. Trying to get a handle on how it all works.

Maybe by then, Mr Warno will be manufacturing these things for sale!

 

[maple1]

Tstat starts system pump(s).

Aquastat maintains boiler temp.

 

[warno]

I guess that hedge I was trying to burn was the cause of alot of my troubles with the smoke. I loaded up the box with some of the maple I got from dad's this morning, he said it's been in his pile for over 2 years after standing dead for years, and it seems to be burning with minimal smoke.

Here's a shot from my kitchen window at idle. The light on the pole is alittle bright but you can see the small trail of what I'm guessing is water vapor because It goes up about 10 feet then disappears.

 

[hondaracer2oo4]

The drier th wood you are burning the less likely you are going to get smoke, but I bet you burned more than you expected to burn last night since the dry wood burns easily.

 

[warno]

I burned about 3 splits of the maple and a little of my lumber pieces. This morning I still had some coals left. I put in what I thought would get through the day. I'm not going to mess with it until this afternoon about the time I would be getting home from work.

 

[warno]

I did do alittle timing and temp reading yesterday when I was doing my clean out. It took less than 3 minutes of fan running time on the boiler to recover 4 degrees of water temp. I'm also reading alittle over 350 degrees on the flue adaptor in the back of the boiler with fan running.

 

[hondaracer2oo4]

Sounds like you are starting to figure things out. I would be really happy with 350 flue temps. My g200 can hit 375 under a good oak coal bed with a load of oak splits ontop. That cuts back to about 325 when the damper starts cutting back the air as it approaches high set point.

 

[warno]

I did a little modification to my natural air intake. This is the only air in the fire box without the fan running. I used to just have a short pipe welded to the outside of the 2" cap. Now I'm hoping this will let the air get a little further forward in the fire box to keep the front coals going too.

 

[Heat1285]

boiler looks great....my advice is BURN GOOD SEASONED HARDWOOD stop burning that scrap junk...like honda said you will NEVER get a cool coal bed established. Now dont get my wrong, i burn all my mill scraps up in my OWB....but i throw in only a few pieces a day when i load on top for that quick blast of heat (adn to get rid of it). HEDGE is the BEST stuff out there to burn and has the highest BTU count of any hardwood.....get as much of that stuff as you can....start stocking up on good hardwood wherever you can get, get it cut , split and stored for 9-12 months and you will never have these problems that you are speaking off. If you dont have any seasoned hardwood for this year try and find some ash to cut down....that stuff has a low moisture content naturally as is the best wood to burn "green." I burn mostly all oak, maple, hickory, ash, cherry and walnut. Having that 2-4 bed of nice coals is extremely important. my advice is to make your round or splits about 4-6 short the length of the firebox, this will leave a few inches on each side and ensure that you can stack a nice even load in there...hope this helps!

 

[warno]

I have been mixing my lumber pieces in with my maple to get rid of the lumber. That seems to be doing pretty good for me. I had a nice bed of coals going but, after work yesterday when I checked it there were still some pieces left to burn in the box so I shut the door and went inside. I thought it would make it till I loaded before bed, I was wrong. It was about a 12 hour burn though. The water temp was fine at 165 but I had to relight the fire. It made it through the night just fine after that.

This morning I had some coals going again. This afternoon should be better yet. I'll just have to get used to tossing in a split or small round after work, no problem.

Thanks for all the advice everyone. I'm going to start getting wood stock piled soon. I banked on burning though what I had and some of dad's stock since he had enough for him in his house already. I have been suppling about 80-90% of his wood supply for about 10 years now so he said it would be fine to take some back. Pretty much all he burns is oak sheet metal skids I get from work. It's all dried oak 2 x 3, 2 x 4, and 1 x 4 boards. He loves to burn this stuff in his furnace.

 

[warno]

I have a question about improving efficiency. I can either try to build an effective venturi to put in front of where my fan blows in, to pull some of the smoke down and blow it up through the coal bed after mixing with fresh air. Or I can build a way to get air up over top of the fire as well as the fan blowing up under the fire. This way I would direct the air flow over the fire to blow the smoke back down into the fire.

I know I can't do anything to prevent the smoking while the boiler is idling but I would like to improve what I can while the fire is getting fresh air from the fan. Would either of my ideas work?

 

[brenndatomu]

I have a question about improving efficiency. I can either try to build an effective venturi to put in front of where my fan blows in, to pull some of the smoke down and blow it up through the coal bed after mixing with fresh air. Or I can build a way to get air up over top of the fire as well as the fan blowing up under the fire. This way I would direct the air flow over the fire to blow the smoke back down into the fire.

I know I can't do anything to prevent the smoking while the boiler is idling but I would like to improve what I can while the fire is getting fresh air from the fan. Would either of my ideas work?

Either could work if designed properly. Keep in mind that you only need secondary air for the first few hours or so. Once the wood is to the coal stage the volatiles and smoke are pretty well gone and coals will burn hot and clean with just a little air from below. Secondary air just cools the firebox and water on the second half of the burn. I wouldn't make too many changes now if you are planning to add storage later, because once you do, you will be able to burn wide open for a few hours and then just shut the damper down once the boiler has a belly full of red hots

 

[warno]

I know it all depends on alot of things (insulation, age of house, heat demand, etc.) But how long, very ball park estimate, would 620 gallons of 180 degree water last in a day?

I got a quote for a 250 gallon propane tank and the guy told me they have a couple of them. If they will fit in my crawl space I'll be getting 2 for a stoarage total of about 620 gallons (boiler and tanks).

 

[Heat1285]

dont inject secondary air unless it is warm air.....my heatmor injects secondary air but it is abour 180° air coming from the rear panel. it is good that ur are letting your fire burn all the way down....that dries the firebox out completely.....i also try and time it so i just have a nice coal bed to relight the next fire

 

[airlina]

I know it all depends on alot of things (insulation, age of house, heat demand, etc.) But how long, very ball park estimate, would 620 gallons of 180 degree water last in a day?

I got a quote for a 250 gallon propane tank and the guy told me they have a couple of them. If they will fit in my crawl space I'll be getting 2 for a stoarage total of about 620 gallons (boiler and tanks).

I just added 500 gallons (repurposed propane tank) of storage to my Econoburn 100 this year. I live in Western NY and while we haven't had any winter yet, I am finding that one 5 hour fire every 24 hours heats my storage to 180 degrees and satisfies my heat load for the next 24 hours. Heat load is a 1700 sq. ft. log house with old style 180 deg baseboard emitters and DHW. I use the storage down to 130-140 degrees before refiring. Hasn't been real cold yet , so I am sure this will change , but real happy with the storage addition so far, adds a lot in the way of convience and cleaner burn. Bruce

 

[maple1]

I know it all depends on alot of things (insulation, age of house, heat demand, etc.) But how long, very ball park estimate, would 620 gallons of 180 degree water last in a day?

I got a quote for a 250 gallon propane tank and the guy told me they have a couple of them. If they will fit in my crawl space I'll be getting 2 for a stoarage total of about 620 gallons (boiler and tanks).

It will also depend on what you have for emitters or distribution. e.g., in floor heat only needs 100-120° water, but baseboard rads or a hot air HX might not be much good below 140°.

Right now I am burning once a day with 660 gallons of tanks. When I go to bed storage is in the 175 range, and I am lighting a fire again late or mid the next afternoon and storage is down to 130-140 (top) at that point. I have slant fin baseboard, but think I have a bit more than a design would call for. Also not heating the whole house when coasting, the upstairs zones don't call for heat until 6pm or so, they set back early morning a couple degrees.

 

[warno]

I will be using a HX in the plenum of our existing natural gas furnace. I can build what ever size HX I want since I'll be using our items from work. So basically I can build a big HX with alot of heat available so the fan only runs a short period of time on it. At least in my mind that theory sounds right. Am I wrong thinking that?

I do have a question with the HX in plenum set up. When the boiler gets down on temps and the natural gas kicks in, does the heat blowing through cool a HX loose alot of BTUs on its way through the house? Also how low can the water temps get before a water to air HX doesn't work well?

 

[lotawood]

A lot of advantages with storage. It would help with your smoke at idle. You can be more flexible with your reloads.

I like when running off of storage, there is not a fire going. So there is less to worry about while you are away. Many boilers burn unattended and you have in the back of your mind I hope everything is going alright.

I don't have experience with forced air, but I would guess a bigger HX would at least allow for running lower temperatures.

 

[warno]

I do have those fears of "is everything ok" while I'm at work or its at night.

I have been pretty successful keeping the coals going and if I kill the coal bed I know what it takes to get it built back up. I've been burning maple lately and its working really well for me. I'm really liking the heat in the garage now. The wife even came out there while I was working and her and my boy hung out for awhile so that's nice.

 

[warno]

another morning update.

I reloaded with a bunch of maple splits last night at about 830. I had to relight the fire at that time. This morning, outside temperature is 29 and foggy, at 630 I went out and all but a small piece had burned to nothing, water temps down to 156 from 170. So I reloaded again and let it take off. I have turned my differintial up to 7 degrees and I'm wondering if now would be a good time to turn it up 10 degrees. So my fan isn't running so often. What do you guys think? If I turn my differintial up some more will I get a longer burn time?

On a side note, I also turn down the thermostat in the garage 10 degrees so the heat load isn't so much. I was running at 70 now it's at 60.

Any input would be great everyone, thank you.

 

[maple1]

There are a lot of variables from setup to setup, and there's only one way to tweak through that - give it a shot & see what happens.

 

[Fred61]

Too many variables with wood heat to find that magic recipe for hitting the perfect coal bed. Not like tuning an oil gun or propane burner. The wood, size of splits, heat load, barometric pressure, wind, how the wood lays in the firebox, etc. etc. all have an effect on your fire. You can tweak the controls and maybe see some improvement but the fire will be different each time. It will be better when winter comes but you'll be chasing the target 'till you get storage then nearly all these concerns will be non issues. On my unit, I don't care what the status of the firebox is when I'm ready for my next fire except a few pieces of charcoal cold or hot, left to facilitate igniting the next fire.