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Post by plazar41 on Jan 26, 2013 18:54:19 GMT -8
Hello all, I am new here. Some back ground for you. Ive been studying every piece of information I can find. Been reading the posts for a while now. I purchased the book on rmh by ito and evans. I am trying to build a 6" system. I set up a link to the drawings of the actual heater I am building. The drawings depict the point of construction thus far. A lot of people use what they can get their hands on, and the same is true here. I am using pavers that measure 4"w x 8"L x 2 1/2"H. Between the book and some videos of Ernie Wisner, there seems to be room for play. For example, the book drawings indicate a space between the insulated riser, and the outer barrel. About 2". in one video, Ernie takes off the top of his rmh heater to show you the inside. He used a brick heat riser, and I didn't see any insulation around the riser, and much more than a 2" gap between the walls. I took a page from that, as I have the pavers to play with. I am building this and testing in the garage before I install in the house. I am questioning the pavers durability, the un-insulated riser, as well as adequate room at the bottom of the barrel. Any thoughts and suggestions would be appreciated. Here is a link to the drawings so far. you can click on each picture for a larger image, or click on the pdf link for all of them on one page. about 1.21 meg www.dawntodusk.net/rocketmassheaterhere is the you tube link the the video with Ernie and Erica www.youtube.com/watch?v=4usXIAoy9us
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Post by Donkey on Jan 26, 2013 23:28:06 GMT -8
The riser MUST be insulated! I haven't seen Ernie's video yet.. I'm just guessin' but if there's no visible insulation jacket, he's using those super light weight insulative bricks. Pavers will probably disintegrate in short order. It gets VERY hot inside, hotter than concrete can take.
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Post by mechartnik on Jan 27, 2013 2:00:42 GMT -8
Please remember that there are generally two types of firebrick (and refractory materials in general): hard, can take the heat soft or insulative, can contain the heat both are available in varying grades as far as operating temperature [there are also classes of ceramics that are only good for lower relative temperatures ie terrocotta]
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Post by plazar41 on Jan 27, 2013 5:17:08 GMT -8
The riser MUST be insulated! I haven't seen Ernie's video yet.. I'm just guessin' but if there's no visible insulation jacket, he's using those super light weight insulative bricks. Pavers will probably disintegrate in short order. It gets VERY hot inside, hotter than concrete can take. Donkey, Thank you for your input. I also questioned the pavers. I will build the permanent one with fire bricks. What about the opening at the bottom. is this sufficient?
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Post by plazar41 on Jan 27, 2013 5:19:08 GMT -8
barrel clearance
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Post by Donkey on Jan 27, 2013 11:52:16 GMT -8
It looks good, as long as the insulation jacket leaves the appropriate amount of room. My sense, without actual measurements, is that if your "barrel gap" (that is the gap between insulation and barrel) is LARGER than what the book would indicate, you should be fine. Is that clear enough? Seems a bit muddled to me, but if you get it, good enough. ??
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Post by johnmaster on Feb 4, 2013 19:27:10 GMT -8
Donkey, Any more info on the bricks you described ealrier in this post? Spent hours building my riser and hope that next time I build an RMH I can figure out a faster easier way.
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Post by mechartnik on Feb 4, 2013 21:05:46 GMT -8
John, contact (PM) me, I have your solution...
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Post by byronc on Sept 15, 2014 14:14:43 GMT -8
FYI, the stove in the youtube video, Ernie and Erica's stove has a riser made of refractory fire brick "splits" and it is insulated on the outside surface with 1" thick ceramic wool.
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