New to the RMH world....

Rocket Mass Heaters, Rocket Ovens, Cold boxes, Solar collectors, etc..
Talk about your projects

Moderator: matt walker

New to the RMH world....

Postby EricVanWick » Fri Apr 18, 2014 7:16 pm

Hello from southwest Va! I'm new to both rocket mass heaters and forums! Hope I can make as much use of all this great info and experience as some of the other new arrivals :D Can't wait to get something going!
Thanks for approving me to join, Matt-
Eric
EricVanWick
 
Posts: 4
Joined: Fri Apr 18, 2014 3:08 pm

Re: New to the RMH world....

Postby matt walker » Fri Apr 18, 2014 8:42 pm

Welcome Eric, glad to have you aboard man.
User avatar
matt walker
Site Admin
 
Posts: 1806
Joined: Tue Jan 03, 2012 5:50 pm
Location: North Olympic Peninsula

Re: New to the RMH world....

Postby EricVanWick » Fri Apr 18, 2014 9:21 pm

Thank u and great to be here. I've been a wood stove guy for 3 yrs in the house my wife & I bought 4 yrs ago, and upon finding out about RMH's I started considering the amount of time spent amassing wood for our heat- so having been thoroughly satisfied by all that I've found online, I can tell that it's time to get moving in this direction. Many questions, of course, but a big one is locating a rocket mass heater in the basement of our small home and using the existing chimney- it's chimney block w/ 6" square clay tile liner- w/ a 6" thimble 4 ft off the slab, which ascends approx 22 ft to suitable height above the roofline- is this acceptable? The house is about 900 sq ft (first and only floor), full basement, and heats fine w/ the old wonderwood I've been using(just soooo much wood used tho). We have plenty of room in basement to stretch out some mass...
Any input would be GREATLY appreciated. BTW, I've seen nearly every video of yours I can find and am impressed w/ both the craftsmanship and the common sense narrative, even an oldish carpenter- turned-transformer technician can understand :lol:
Thanks again and hope to hear back!
Eric
EricVanWick
 
Posts: 4
Joined: Fri Apr 18, 2014 3:08 pm

Re: New to the RMH world....

Postby matt walker » Fri Apr 18, 2014 10:05 pm

Oh geez man, it's almost the perfect set up! The only caveat is the whole basement thing, and the chance that in certain conditions the house can be a better chimney than the chimney so the draft is reversed. I think you probably won't have much of an issue since it has a proper chimney, and it's not insurmountable.

Other than that, space to sprawl and on slab with a proper chimney in a common size. I'm flat out jealous, I'd be building a monster down there!

Oh, I almost forgot, the fact that your house is 900 sq. ft. is a big plus. An RMH can pretty easily keep a space that size comfy.
User avatar
matt walker
Site Admin
 
Posts: 1806
Joined: Tue Jan 03, 2012 5:50 pm
Location: North Olympic Peninsula

Re: New to the RMH world....

Postby mannytheseacow » Sat Apr 19, 2014 1:26 am

Welcome, Eric! Great to have you here.

Your situation sounds very similar to my own, though you're probably in a warmer climate. Otherwise, basement, chimney, square footage... all very much alike. I'm pretty sure I'm burning way less wood than my old fashioned stove, but be prepared to spend way more time splitting.

I can't wait to see what you come up with. These things all take on their creator's personality.
"Knowledge is power. Arm yourself."
User avatar
mannytheseacow
 
Posts: 942
Joined: Sun Feb 24, 2013 12:40 am

So then....

Postby EricVanWick » Sat Apr 19, 2014 2:32 am

Thanks for the responses, fellas. After reading as many posts of both of ya's as I could over the last week, I know I can tap into some serious and helpful knowledge! Can't say enough about the positive and supportive tone of all the posts, including the other guys in the forum- very refreshing!
I notice on the cast J tubes there doesn't seem to be any secondary air intake, but in many videos, guys are sticking pipes into or making holes for more air to aid draft... Does anyone think that since I'll be RMH-in' it in the basement that I might need to provide additional air to keep things flowing in the right direction?
About local clay- 6"'s under the grass here, we have an orange, sticky, not fun to dig, some times chunky clay. In a nutshell, aside from experimenting, what sort of characteristics should I look for?
On another question, the need to maintain CSA throughout the system, when placing drum over riser, I haven't fully understood how much area there should be at the lowest level- that space exits into cob bench and and then to chimney? All this is new and there's so much info, it's a bit overwhelming. Admittedly, I need to seclude myself while researching, 2 dogs and my wife are somewhat distracting :roll:
Oh yeah, read that post about the Craigslist wood splitter! Mine's been getting plenty of use for stove size wood. Thinking about modifying wedge to make multiple splits on already busted wood.
All in due time-
Lookin forward to more sharing-
Eric
EricVanWick
 
Posts: 4
Joined: Fri Apr 18, 2014 3:08 pm

Re: New to the RMH world....

Postby Bobwieser » Sat Apr 19, 2014 12:57 pm

I think the information you want can be found in Peterbergs post on the first page of this link. http://donkey32.proboards.com/thread/337/helpful-hint He has a formula and an example. Here is his post that I have cut ,pasted and added quote marks.

"Very true, Donkey. I've attended a rocket mass heater workshop in the Netherlands last week and we've had a heated discussion about this very same point. I'd cut out the opening at a little bit larger than system size, and the instructor of the workshop insisted it was far too small.

This is what I've learned this week:
There's a difference between a stream opening and a stream profile. The main culprit is the gap between insulation canister and barrel. When you're only looking at the opening in the side of the barrel, it's easy to think you have to make the opening the same as system size. This is utterly wrong, because the gases are not streaming straight out of the opening. Instead, it is coming from left and right, and from the top. Moreover, in the corners two streams can't pass there at the same time, so you have to compensate for that.

Maths can help here. Start with system size area, divide it by the gap between inner and outer barrel, add twice the size of the gap for the top corners and you've got the length of the stream profile. The profile length consists of the top rim and sides of the opening.

For example: system size of 8" equals a little bit more than 50" square. The gap is, say, 2" wide, which will get us at 25", adding the gap twice will give us 29". Presuming the opening is one foot wide, the height need to be half of 17", which is 8.5 inches. The open area in this instance will be about 90" square.

The resulting opening in the side of the barrel will look enormous, nevertheless this is absolutely the correct method. The recommended gap is smaller than in my example, so the profile length will be even larger.

P.S.
The top rim is rounded, so you have to measure it along the contour, not as a straight line."

I had to read it through a few times to get it. Using his example helped me sort it out.
Good luck and welcome abord.
Bobwieser
 
Posts: 63
Joined: Thu Feb 20, 2014 3:21 pm
Location: New Hampshire

Re: New to the RMH world....

Postby 4seasons » Sat Apr 19, 2014 1:37 pm

Welcome aboard Eric. Sounds like your current setup is very similar to mine. I have a similar size house and am using a Wondercoal thru a 6 in thimble and into a 6 in square clay tiled chimney. Even our climate would be about the same as I am just a few miles down the road from you in Greeneville, TN. The biggest difference is your basement setup where mine is in the living room. That means you will need to come up with a way to move the heat to the main floor although I would say you have already figured most of that out with your Wonderwood.

About your clay, have you done a clay test yet? If not fill a clear jar half way with your dirt that you think may work. Then fill the jar the rest of the way with water leaving a little room to shake. Shake it up and then set it down and see the sand and rocks fall out first followed by silt and the clay will stay suspended in the water for hours. There are more test you can do and more details to this test but it will give you an idea of what kind of dirt you have.
User avatar
4seasons
 
Posts: 100
Joined: Tue Jan 14, 2014 4:55 pm
Location: Greeneville, TN

Re: New to the RMH world....

Postby matt walker » Sat Apr 19, 2014 2:50 pm

They guys have great advice Eric, the only thing I'll add is don't sweat those parts that you just can't quite picture completely yet, and don't worry about the clay too much. Get out in the yard and get muddy, make a little bucket of mix. Maybe cast a funny little J with your clay and a cardboard mold or something. Once you get your hands dirty you'll answer a lot of your own questions, and the manifold area is one of those that I just couldn't picture but when I got there and started making a transition with mud balls I just started laughing because of course I couldn't picture it. It was just too damn simple.

Oh, yeah, the secondary air thing. For the most part the folks doing that are building uninsulated metal stoves and they just aren't able to get hot enough to perform the same way a simple insulated masonry J does. You will only hurt performance by trying to add air downstream. Peter van den Berg has developed the P-channel which does improve the standard J and I recommend adding one to your build, but in my opinion it mostly guarantees that the flow of air down the feed in the front isn't obstructed by fuel. It does work and is worth doing, but I'm not sure "secondary air" is the right term for it. At any rate, semantics aside, you will probably not want to apply the metal stove stuff to one of these. An insulated masonry J can get complete combustion that a metal stove really can't do without eating itself alive, and It achieves it in a dead simple design. You won't improve it by fooling around with it much, although as you can tell by watching my videos, that hasn't stopped me! So, if you really want to fool with it, by all means man, add in some air tubes. We all learn from every iteration of these things, in my opinion.
User avatar
matt walker
Site Admin
 
Posts: 1806
Joined: Tue Jan 03, 2012 5:50 pm
Location: North Olympic Peninsula

Feelin' it!

Postby EricVanWick » Sat Apr 19, 2014 10:31 pm

Hey y'all-
Thanks for the barrage of responses and info! Man, this stuff is the "goods." It'll be just a little while til I can get started, but certainly can't wait too long- I've got a few side projects to take care of, a belated honeymoon to take, and then I'll be freed up to hit this w/ all I've got! I appreciate all the advice; probably won't mess w/ downstream air, Matt- I'm all for fiddlin' and tinkering, but to be ready for next heating season I really want to focus on a straight forward build. I'll keep reading posts past present future, and when I get started, I will probly be lighting up this board!
Honestly, right now I'm wiped out- spent the late morning, early afternoon cutting fire wood, and the rest of the day hauling and splitting... But it sure is a sweet pile of hickory in the back yard!!!
Thanks again for everyone's input, be posting soon enough,
Eric
EricVanWick
 
Posts: 4
Joined: Fri Apr 18, 2014 3:08 pm

Next

Return to Heating and Cooling

Who is online

Users browsing this forum: No registered users and 10 guests

cron