Indoor wood boiler (gasifier)... but outside?!?

[ewang]

New member here. People from GarageJournal recommended this forum as a wealth of knowledge on heating with boilers. They were right! I've done a bit of searching and have already found a lot of good opinions and recommendations. Here is a topic that I haven't successfully found: using an indoor (high efficiency) wood boiler, outside (in an insulated shed).

I started searching for a new outdoor wood boiler, after 10 years of faithful service, my current Johnson OWB ended with a water jacket leak. The initial cost back then was around $6200 for furnace and installation.

Now, we are looking at prices somewhere between $5-$8k just for a new OWB (Outdoor Wood Boiler).

Assuming the new furnace lasts as long as the old one, you can assume $600-$800/yr for the privilege to burn wood outside.

Today, I had the crazy idea of placing an indoor wood boiler, outside. I plan to build an insulated shed around it, piping into the existing pipes. I know I would have to add additional controls, but I can get those pretty cheap. I would also make an outdoor air intake for the shed. I would look for an indoor model that is insulated, with a capacity matching our existing boiler of 150,000 btu/hr.

My thoughts
Pros:
-Less annual cost assuming indoor boiler last longer, due to firebrick design.
-Possibly more efficient, leading to less wood consumption.
Cons:
-PITA to load wood. Now you would have to go through two doors to fire up.
-Shorter wood pieces
-Broken fire brick.

Please share your comments, ideas and concerns. I can't be the first to think of this!

Thanks in advance.
Ewang

 

[Nofossil]

New member here. People from GarageJournal recommended this forum as a wealth of knowledge on heating with boilers. They were right! I've done a bit of searching and have already found a lot of good opinions and recommendations. Here is a topic that I haven't successfully found: using an indoor (high efficiency) wood boiler, outside (in an insulated shed).

I started searching for a new outdoor wood boiler, after 10 years of faithful service, my current Johnson OWB ended with a water jacket leak. The initial cost back then was around $6200 for furnace and installation.

Now, we are looking at prices somewhere between $5-$8k just for a new OWB (Outdoor Wood Boiler).

Assuming the new furnace lasts as long as the old one, you can assume $600-$800/yr for the privilege to burn wood outside.

Today, I had the crazy idea of placing an indoor wood boiler, outside. I plan to build an insulated shed around it, piping into the existing pipes. I know I would have to add additional controls, but I can get those pretty cheap. I would also make an outdoor air intake for the shed. I would look for an indoor model that is insulated, with a capacity matching our existing boiler of 150,000 btu/hr.

My thoughts
Pros:
-Less annual cost assuming indoor boiler last longer, due to firebrick design.
-Possibly more efficient, leading to less wood consumption.
Cons:
-PITA to load wood. Now you would have to go through two doors to fire up.
-Shorter wood pieces
-Broken fire brick.

Please share your comments, ideas and concerns. I can't be the first to think of this!

Thanks in advance.
Ewang

Welcome to the forum. You're right on all counts. It's a good idea, and many people have done it including a former moderator. I'm sure lots of folks will chime in. You're on the right track.

If you use a gasifier, you should see a dramatic reduction in wood consumption. You'd be loading smaller and shorter pieces of wood, but a lot less of it. Most folks use a barn or build a small outbuilding with room for a boiler and a week or so worth of firewood. That way you're loading the boiler in a warm and enclosed space instead of outside in the snow and sleet.

 

[Hunderliggur]

I have my boiler in an outside shed (insulated this year, uninsulated last year). The shed is 12x16. I have a boiler room that is 6x12 and a wood area 10x12. There is an outside door to the boiler room, an interior door to the wood, and barn boors to load the wood. It works fine and makes a great man cave ;-). I had one issue with the pipes freezing last year (first year) but they are well insulated now and with the 6x10 insulated boiler room I do not expect any issues this year. It is very comforatble to load wood since the build is warn due to the boiler.

 

[sublime68charger]

this is the start of my Boiler in its own enclosed area all that was up at this time was the dividing wall between the boiler and the Wood Storgage area.

I finished out the room around the boiler 4 months later and her's a Pic of the current setup.

I have a 4" round "Dryer Vent" opening in the back wall of the boiler room for fresh air intake.

has worked for me since 2005.

sublime out.

 

[Tennman]

I built a small barn for our BioMass gassifier. The barn has a large overhang where wood is stored and dried. It's about 120' back behind our home mainly because I'm goofy about the arrangement of our outbuildings. We're near the Tenn/Alabama border so our weather is nothing like yours. But.... I actually enjoy going out and caring for the "beast", but my going "out" is nothing like yours in Wisconsin. Running our efficent indoor boiler away from the house in a barn is really the only way I'd want to operate. Many here prefer the efficiency advantages of an indoor install. I chose less efficiency to keep the dirt, smell, and bugs out yonder.

 

[sublime68charger]

from front door to shed door is 60' for me. Not to long of jaunt in sloppy weather I change to my outside untied boot's and throw on the old over coat make my walk and then I inside and my shed. shed is alway's 20 degrees warmer than outside temp "I've not had a water bottle freeze out there yet."
then I"m out of weather it can still be cold out there but dont' have the wind chill effecting me inside the shed.

would is dry and free of snow as well. Shed is well lit also so that is nice for the early morning/late night stove fill up's

when my inside supply runs out I have a ATV trailer that I fill up each weekend and pull off that for the week and fill up again next weekend.

I can store 3.8 Cords in the shed and avg about 6-7 Cords a year.

but wood is my sole heat source. I have Gas backup but hardly ever turn it on.

sublime out

 

[flyingcow]

My tarn innova is next door in my garage(eerrr) I mean wood storage facility. Love it, for me a good set up. But I have thermal storage in my basement. Basically fire the boiler up once a day(takes 10 minutes) and I'm done. Live in northern Maine, on a hill, damn cold at times. No heat in my boiler room, except for the boiler itself. Boiler fires up for maybe 5 hours a day.

BTW..this site kicks azzz. Plenty of good people here. WELCOME

 

[sublime68charger]

flyingcow,

eerrr my shed heard that. it also leads a double life.
How much storage due you have in the basement?

I want to get 1/2 my basment finished off and then put in some storage in mine as well thinking I would need at least 500G.

thanks sublime out.

 

[ihookem]

I have an EKO 25 in a 6x6 shed outside 120 ft from the house. It works very well and like it a lot. You will notice how nice it is when the wind is blowing 30 mph in the winter too. I go right in there and load it in a small shed that is 90 degrees inside. It keeps 2 days supply of wood for when I know a snow storm is coming and the 90 degree air dries out any surface moisture in the wood. The only thing I did wrong was make it too small. I made it 6x6 so it would look like an OWB. I live in allenton Wisconsin and if you want to see it just say ok. I will send you a pm for my phone number if you want to look at it.

 

[ISeeDeadBTUs]

MY GW is about 75' from the house. The back door of the garage puts me on a path to the 'boiler room', an 8' X 10' room housing the boiler and two rows of 6' high 10' oak.

Intuitively. she'd be more efficient inside the residence. But I am happy she's not.

Jimbo

 

[flyingcow]

flyingcow,

eerrr my shed heard that. it also leads a double life.
How much storage due you have in the basement?

I want to get 1/2 my basment finished off and then put in some storage in mine as well thinking I would need at least 500G.

thanks sublime out.

820gal

 

[airplanes20]

I just installed a Tarm Scandtec solo plus 140,000 btu. I put it in a outside woodshed about 75 feet from the house. I built a 12 by 14 shed insulated it with 4 inches of blue board hoping to keep the mice out. I ran 1 and a quarter inch pex pipe from the boiler into the house i took sheets of 2 feet by 8 feet by 2 inch blue board insulation and cut them into 8 inch pieces. Then i built a box around the pexpipe from the boiler to the house out of the insulation. I doubled up on the insulation giving me an R-20 all around the pexpipe. So far I am only losing maybe 2 degrees from the boiler to the house. I put the pipe down about 3 feet in the ground, but the ground around my house is all sand. If you have land that is wet I heard you only want to put the pipe in the ground like 2 feet so your not fighting the temp. of the ground water. I also ran a 2 inch SDR 40 pipe so i could run power and thermastat wire out to the wood shed.

I put two storage tanks in the basement, because you do lose heat off the tanks and i would rather have that heat inside the house then wasted in the boiler room. The boiler room stays around 70 degrees, just off the heat of the boiler.

I am glad i put the boiler outside, all the mess from the wood is outside, there is no smoke inside the house, plus it is nice to have a "man cave"
I live in the White Mountains of New Hampshire, Ill have to post some pictures.

 

[Hunderliggur]

flyingcow,

...I want to get 1/2 my basment finished off and then put in some storage in mine as well thinking I would need at least 500G.

thanks sublime out.

$500G should be enough to finish half your basement and take care of your storage and wood addiction ;-)

 

[b33p3r]

I built a 10'X12' insulated shed specifically for my econoburn 150 and wood storage 70' from house. Not fired up yet...1-2 weeks and hoping. My thoughts were to keep all the wood mess outside the house. Also a great reason to get out for a breath of fresh air in the winter months.
Pro's: No mess in house
No bugs in house
Fire insurance benefits?
Split and cut wood right where you need it
get some winter air in your lungs

Cons: Extra cost of storage shed
Extra cost in piping from shed to house
Forced to go out and get winter air in lungs

 

[sublime68charger]

flyingcow,

...I want to get 1/2 my basment finished off and then put in some storage in mine as well thinking I would need at least 500G.

thanks sublime out.

$500G should be enough to finish half your basement and take care of your storage and wood addiction ;-)

yep it should now If I just had the 500G to test that theory!

sublime out.

 

[BHetrick10]

I am new to the idea of putting an indoor outside. Seems like a lot of BTU get wasted? Some have stated that there wood shed get to 80* or better. Do you think the shed style OWB loose this much heat as well? It would be neat to look at them with a thermal camera to find out.

I don't quite understand the storage deal. I know you have all those BTU on stand by, but you still have to get the water heated up. Even with the best insulation job I doubt you could contain all the heat. Why does it matter if you burn more often for shorter periods with no storage vs longer burns less often with more storage.

My situation is I have a 2,600Sf building. There is a loft area above some of it 360 SF. The main part of the shop has 16' high ceilings. I also have a 480SF area up in the attic. I have radiant in floor heat. I plan to build a house in the next few years, that will probably be 2,500-3,500 SF. The shop is not heated right now as I didn't purchase a boiler yet. I am going to have a building out side for the boiler. I didn't decide on an indoor out outdoor one yet. I would like a gasser. I don't want to have storage if it isn't necessary as I currently don't have the space, nor do I understand it.

I would like to have a min of a 10 hour burn as I am usually away for that long at work. I dont want to have to start from scratch with a new fire every few days. It would be nice just to through wood in two times a day.

Seems like an IWB and putting it outside is a good idea other than loosing BTU's. The units have been around longer and more of them area out on the market.

I also cant seem to find how many BTU per SF I need. I keep hearing anything from 200,000- 450,000. Both shop and house will be radiant.

 

[flyingcow]

Well, I'm not good at explaining things. But....


I have an indoor gasser inside my unattached garage. In it's own room. i do not heat the garage, it's just used for a wood shed.

I have 820 gals of storage in my basement of my house. I start 1 fire every day(takes all of 10 maybe 15 minutes), this fire will recharge my storage(I think of it as a battery) and also heat my house at same time. With storage the boiler runs pretty much wide open, in about 4ish hours the fire goes out. My house pulls energy back out of the tank for the next 20 hours. Works well for me. In the summer, I start a fire about every 5 days to recharge storage tank. This gives me DHW for a family of 5.

The E-classic(OWB) salesman told me 1 cord of wood=100 gals of oil

Using a gasser, 1 cord of wood=150 gals of oil,sometimes closer to 175 gals. This is my experience.

I was using about 1,000 gals of oil a year. This has been replaced with 6.5 cord of wood. And I'm keeping my house(when we're home) at 72 degrees. When we used oil, the T-stat hardly went above 68.

Storage does help use a little less wood, but having it gives me more flexability. Especially in the shoulder season.