Outside Wood Boiler

[sscrob]

I bought a Hardy H2. Use it to heat a 4000 ft house and my hot water also. Paid 6500 for mine with 2 pumps, one for house the other for a future shop. I installed it myself, they are pretty simple. Brother in-law sells Heatmor now and they look like good units too. I've read bad stuff about Shaver stoves, CB and Taylor are ok from what I've seen.

 

[jpm1]

I have a "Classic" outside Central Boiler that is not EPA certified and to be honest i really dont care either. I have had one for 4 years now and its great! in fact we have 8 of them in our family. Ours doesn't eat wood like people would think, their very easy to tend to and the mess is all outside and risk of a chimney fire is non threatening to your house. I burn only seasoned wood but can burn any type of wood (meaning hard wood or soft wood) with the same heating results only thing is soft wood . . .(IE, pine, hemlock . . .ect) leave no coals and when the woods gone so is your heat. I'm heating 1600 sq ft of floor space averagiing 78 degrees and last year burning 9 months i used 12 face cords of 20" wood. i have my own wood, equipment to cut and move it so and OSB is a no brainer for me. When i cleaned my OSB out this june all the ashes fit in the bucket of my Kioti FEL bucket which is a 66"er. it looked like "baby Powder except greyish in color. For me, no one can ever talk me out of my OSB, nor will i allow any one to shut me down from operating it! I LOVE MY CENTRAL OUTSIDE BOILER! ! ! . . .John

 

[mikehaugen]

Maybe some people prefer the green woods because it burns slower and still puts out enough heat for their needs, therefore more time between fill-ups? Just a thought. It is my understanding that "green" wood and "soft" wood creates for creosote, meaning more chimney cleanings. Maybe not as big of an issue with an outdoor boiler.

 

[dmccarty]

I know of an area that has 5-6 outdoor wood burners. They have been in use for at least seven years but I think they are much older. When I pass through that area on a cold morning it can be like driving through bad fog due to the wood smoke. No way would I have one of those things. If a neighbor had one I would be complaining. It really is that bad. I don't know how they put up with the smoke.

Now down the road a bit, a guy put in a shed with a burner a couple of years ago. THAT unit is pretty danged nice. It smokes very little and I have to look real close to see if he is actually burning. On some days I can tell that he just started up the unit or added wood but I doubt most people driving by even notice. It simply does not smoke much. I don't know what they other people are using but this guy splits and drys his wood. I do know that one of the outdoor stoves that smoke alot has a nice wood shed so I think he is burning dried wood.

The flip side to wood burning is the cost. If I had to buy wood at $100 a cord it would just be cheaper to heat the house with power. Around my place a cord, 4x4x8 is about $200. We heat our house with an indoor stove which works real well.

Later,
Dan

 

[mikehaugen]

Around here it's about $120 a face cord! probably in the neighborhood of 250-300 for a cord for hardwood. I don't buy it, but I don't use much yet. I am thinking about wood burner/ boiler but won't unless I am confident I have a cheap/ free source of wood.

 

[Fi-Q]

I ve been reading on boilers for year. And some far what i have learn:

I want a inside boiler ( will be either in detach garage pr boiler barn)

Get a gasification boiler this is a must. Burn seasonned wood.

Go read in the boiler room on hearth.com, tons and tons of info on that specific sbuject

 

[Pete Judd]

I know a local guy that has one he built in the shape of a long box, holds about 10,000 gallons of water. Has no closed top, so does not have to be classified as a "boiler" as never any pressure. It has a large brick lined firebox 24x36, and a blower to help start the fire. The fire/heat excanger tubes are 4 inch tubing, and they enter a box on the far end of the box and another set to come back through the water before the chimney. The door has a thermostat controlled draft, that when the water gets to 205 F it closes and the fire will go out. He heats his old large farm house, greenhouse, all hot water, and their hot tub with it. A lot of firewood around here to be gotten for free, except for labor, chainsaw gas&oil, and transport fuel. He says that about 8 cords a year for his setup, and he throws all his household garbage in the firebox as well. He only needs to have a fire a couple of times a week in the winter, and maybe once a week in the summer. He does spend some time each month working of the water, as is keeping it rust free, and the PH right. When he needs to add another heating circuit, he just drops a copper coil in the water, and another pump.

 

[nybirdman]

I know a local guy that has one he built in the shape of a long box, holds about 10,000 gallons of water. Has no closed top, so does not have to be classified as a "boiler" as never any pressure. It has a large brick lined firebox 24x36, and a blower to help start the fire. The fire/heat excanger tubes are 4 inch tubing, and they enter a box on the far end of the box and another set to come back through the water before the chimney. The door has a thermostat controlled draft, that when the water gets to 205 F it closes and the fire will go out. He heats his old large farm house, greenhouse, all hot water, and their hot tub with it. A lot of firewood around here to be gotten for free, except for labor, chainsaw gas&oil, and transport fuel. He says that about 8 cords a year for his setup, and he throws all his household garbage in the firebox as well. He only needs to have a fire a couple of times a week in the winter, and maybe once a week in the summer. He does spend some time each month working of the water, as is keeping it rust free, and the PH right. When he needs to add another heating circuit, he just drops a copper coil in the water, and another pump.

I THINK HE MENT 80 CORDS A YEAR,REALLY 10,000 GALLLONS OF WATER TO 205 DEGREES FOR A YEAR on 8 cords of wood don't think so.Central boilers also are not pressurized and have a control door for draft.

 

[PapaPerk]

I can't believe people think burning green wood is a good idea! :grumpy:

 

[MNBobcat]

I can't believe people think burning green wood is a good idea! :grumpy:

Burning green wood is a great idea. In wood boilers the best way to feed them is with a mix of seasoned and green wood. That way you get long burn times. If you load the boiler with only seasoned wood, you might not get a 12 hour burn.

I personally only burn wood that has not been seasoned. I also try not to split anything other than the rounds that are two big to lift into the boiler. I easily get 12 hour burn times.

I want to do as little work as possible with my wood. One thing a lot of people don't think about is that how they install their boiler makes a HUGE difference. I just have to shake my head at people who install a boiler and then go cheap on the underground lines and then they comment about how much wood they go through and that the snow melts where their lines run between the boiler and the house. Duh! They probably go through a third more wood than I do because they give up so many BTUs to heating the frozen ground.

Next...people will run long runs using 1" pex and then plumb everything inside their house in series. They can't push enough water through 1" pex on a long run. So they have BTUs they can't use. Then by running stuff in series, say your furnace followed by a HX for the hot water, you reduce the line size to about 3/4" in the HX for the furnace and then with the low water flow to the HX for the hot water heater it can't draw the BTUs it needs.

I ran a primary/secondary loop using 1 1/4" pex. My 1 1/4" line comes into the house, makes a loop (still 1 1/4") and returns to the boiler. Then I have a separate pump for each line that comes off that loop. And a controller to control the pumps. When my furnace calls for heat, its the primary circuit and it turns on the pump to send hot water to the HX in my furnace. If my hot water heater calls for heat, it has its own pump as well. Since things aren't in series, each "leg" can flow a lot more water.

The pump on the main loop is a larger pump than the secondary pumps.

All pumps are grundfos 3-speed pumps. I can flip a lever for the speed setting on each pump and optimize it for it's purpose.

All pumps are located inside of my house. If a pump fails, I'm inside nice and toasty warm replacing it rather than standing out in the cold.

In other words, I tried to optimize the system where it can pull off as many BTUs for each circuit as needed.

Your boiler design can have a big influence on how much wood you use. I spent more money up front (with extra pumps and such) but the payback is that it works incredibly well and because its more efficient I use less wood.

Also, I had no desire to be standing outside, in the dark, in the wind, filling a wood boiler. I built a 12 x 24 foot building using pole building metal and posts. I poured a cement slab for the floor on the half of the building where the wood boiler sits. A 3 foot high block wall separates each side of the building so no coals can roll over to the side of the building where I store wood. I used metal studs where the walls were close to the boiler. There is nothing flammable near the boiler. I installed a louvered fan I can turn on to evacuate any smoke from when the boiler door is opened.

As for the gasification boilers, they are more efficient but you have to burn very, very well seasoned wood or you have problems.

I can go drop a tree, cut it up and burn it the same day. I've not had to clean my chimney in 3 years. I've checked it each year and its been surprisingly clean. I also have very little smoke from my boiler. Not sure why. I have a fairly tall chimney to get out the roof of my building and perhaps its changed how the boiler burns and draws.