Outside Wood Boiler

[Storm56]

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.

I agree with much of what you state in your post, except for the green wood part. As I have previously stated, I do much better with seasoned wood, and I have no trouble getting 12 hour, (longer if I load the stove with more wood), burn times. I installed the unit in 2004 so I have a few years under my belt for experience. I always find it amazing how people have such different experiences using the the same or similar products.

 

[MNBobcat]

I agree with much of what you state in your post, except for the green wood part. As I have previously stated, I do much better with seasoned wood, and I have no trouble getting 12 hour, (longer if I load the stove with more wood), burn times. I installed the unit in 2004 so I have a few years under my belt for experience. I always find it amazing how people have such different experiences using the the same or similar products.

True! The one missing component though is we haven't said what kind of wood we're burning. That may influence different experiences.

I'm burning mostly red oak.

 

[clemsonfor]

I honestly would put a nice woodstove in the house. In KY you will probly burn 3 cords a winter and be able to keep your house over 75F in the entire house. Get a big CAT stove and put a few fans around to move the air, you will be able to heat 2500sqft easy with a stove in the house.

 

[clemsonfor]

View attachment 280124I 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

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.

You can burn pine in any stove inside or out. They do not crosote up your chimney more than oak. There is actually a test that shows green hardwood makes more crosote than green or dry pine. Anyway its a wives tale and seasoned wood under 25% MC is all that should be burned no matter what its going in.

I have an EPA stove in the house with a CAT. Driving by my house unless i am running in by-pass to heat up or just reloaded it you will never know i have a stove going unless you look very hard at the chimney to see the heat waves. There is just no smoke.

 

[cqaigy2]

You can burn pine in any stove inside or out. They do not crosote up your chimney more than oak. There is actually a test that shows green hardwood makes more crosote than green or dry pine. Anyway its a wives tale and seasoned wood under 25% MC is all that should be burned no matter what its going in.

I have an EPA stove in the house with a CAT. Driving by my house unless i am running in by-pass to heat up or just reloaded it you will never know i have a stove going unless you look very hard at the chimney to see the heat waves. There is just no smoke.

My EPA non-cat stove sips wood. If you look at the stove pipe you can see wavy hot air but little to no smoke.