Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: Bull on February 10, 2011, 08:28:27 AM
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This question is for Willie and others that built there own or anyone else that can help. How much and what kind of insulation did you use on your OWB. At what point does the R value around the stove become to much? I am thinking about re insulating my Hardy h2 for next year with rigid 4X8 insulation and was thinking about 6 inches all around and then put metal on to match my garage. I have plenty of insulation and can go with more but don't want to over do it to much.
Thanks
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bull..i don"t think its possible to over insulate. i have r79 worth of insulation,2 layers of 30 1 of 19. im sure their is a formula of whats needed for capacity but i dont know. i think more is better!
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If you've considered spray foaming your lines into the ground, consider having your homebrew OWB spray foamed at the same time. It wouldn't add much cost to the spray foam project and it would give you a much higher R-value per inch. :thumbup:
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i caution using spray foam on your OWB. My neighbor did his like that, had a boil over while not home and boiled the thing pretty much dry, the outer shell now became hot enough to melt some of the insulation. that left him with a big air pocket between the water jacket and the insulation, also the melted part of the insulation no longer insulated well due to the fact that the tiny air sacs no longer existed.
What i used on mine was something called "tank wrap" it is 2 inches thick but rated for 1200 degrees, it is cold to the touch. as for how much is too much, i have no real idea but i would say layer it on untill you feel (or can test with one of them heat gun thingies) no heat loss. also i am a believer in putting a shed around the OWB, i think if you can stop the fierce winter winds from having direct contact with the OWB you will save wood and prolong the life of your OWB
If you live on the farm , you will know (or see) that the wind can drive snow and moisture right through (actully in the smallest crack) the steel walls of a barn or drive shed. I have seen snow inside my shed where the snow has been driven under a tiny crack between the J moulding and the siding. It is my belief this can happen on your OWB as well (a lot of the ones i see are sided just like a drive shed) If this happens now you have snow under the siding and against the insulation that will melt and flow to the bottom of your OWB and sit there in the heat and cause rusting until it dry s up. When i insulated mine i also used the aluminum cladding that they use on pipes in teh chemical and oil refineries, then caulked the overlaps.
sorry for being long winded but i think keeping yoru stove dry on the outside is as important as good under ground lines (i learned about them from a bad experience)
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I agree with Willie the wind is your enemy.I insulated mine with one layer of r 19 on the sides and 2 layers on the roof.I still had snow on the roof of my boiler.So I think I did well on mine.I wouldn't spray foam it if it was me.I want to be able to pull the siding off and pull the insulation back if for any reason I need to fix something.That would so suck to have to scrape and chisel the foam off to make a repair at 9pm in the middle of winter.No thanks im sticking with fiberglass bats.
My buddys NC has some sort of foil backed blanket all around it.He thinks it needs more insulation than what it has.
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just a follow up responce,last week went to my house up north and didn't get my friend to load my furnace at home so i brought temp up to 190 deg wed night before leaving.then shut it down,circulator off,came home sunday evening to find temp only dropped to 145. it was nice to see how well it held temp for that long with nights in 20s and high teens.
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just a follow up responce,last week went to my house up north and didn't get my friend to load my furnace at home so i brought temp up to 190 deg wed night before leaving.then shut it down,circulator off,came home sunday evening to find temp only dropped to 145. it was nice to see how well it held temp for that long with nights in 20s and high teens.
How many hours total? What brand and model? How many gallons of water? Curious about mine.Thanks
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rosewood I think made his own.
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its a homemade,i figured it to be about 90 hours being off.that figures out to be about a half a degree a hour heat loss. water capacity of 1200 gallons.