remember that in a square tube, gases have a lower velocity, down to stalling in the corners. So the CSA of a square isn't as big as it seems to be. It all has to do with the boundary layer and friction.
If it pulses (slowly), first flowing forward in the "right" direction, then reversing and smoking back, then reversing again (and so on).. You may have a constriction downstream somewhere. If it wasn't doing it before and suddenly starts, it's past time to clean the ash out of the bench..
Post by Dan (Upstate NY, USA) on Nov 30, 2013 0:28:12 GMT -8
Ah another good one, if you have CONDENSATION problems like I had INSULATE the cleanouts. ALL my condensation problems came from uninsulated metal cleanouts created a lot of leaky condensation problems for me. After insulating my metal cleanouts with rockwool all my leaking condensate went away.
Would it be possible for someone to state specifications for the following critical aspects; "Check your barrel gap check your flue transition and it's gap. Check if you've insulated the parts well. Check your chimney Check if your horizontal run and elbows isn't too much for the core to push."
Shouldn't be any smaller than CSA, (cross sectional area of the heat riser) the area is calculated multiplying the circumference by the gap between the barrel and the top of the heat riser.
Example: 15cm x Π x 5cm = 235cm² which is bigger than the 176cm² of the heat riser CSA.
Same principle goes for the flue transition, tho, it's better practice to make it at least twice the CSA, so in this case 352cm² would be good.
Insulation wise, i'll go for numbers we kind of know.
Rockwool, at least 5cm all around, same for vermiculite. Peter said to me 1 inch of perlite, or 2.5cm works. As well as 1 inch of super wool. At least the burn tunel and heat riser should be insulated this way. Better to do this to the lower part of a J tube too. Batch rocket should be insulated all around the batch box as well as the heat riser.
Horizontal flue wise, we know that
A 6 incher J can push a good 30 ft of horizontal tube, with no elbow. An 8 incher can reach 40 ft. This is straight pipe. For each 90° elbow, reduce the lengh by three feet.
Well, check your chimney, for soot, plugs, draft, burning a bit of paper directly in the chimney. Check if it goes at least 2ft above the apex. Check on windy days, if it doesn't have bad behavior of pushing gases back in the house. This can be done with incence.
Rocket, not rocketing when placing the barrel without chimney and without insulation.
No insulation means you haven't got enough stack effect to counteract the problem the barrel causes.
What happens, when you're placing the barrel on top of the heat riser, you reduce the height differential between feed and "exhaust" which in this case is the bottom of the barrel. But you reduce the temp differential, the barrel keeping heat that the outside air; on top of the heat riser; would shed normaly. Plus, the gases haven't got enough time to cool down enough, so they would fall out. So they tend to stay in the top of the barrel, this stalls the fire, which starts burning the other way. Then the gases cool down, and go down the heat riser. starving the fire from oxygen for few seconds, making a smoky burn. Then fresh air is comming down the heat riser, and there's is no way to revert it. Plus if your barrel is dark and exposed to the sun light, it might even heat the air inside, just a smidge, and make it raise ( i know Karl! )So without a chimney and it's stack effect, you can't have a working rocket.
Solution, make a base for your barrel, a nice transition, and adapt 10 feet of vertical pipe.
Does more output equal more storage when the mass remains the same size?
With the mass staying the same, more energy will be deposited and therefore will stabilize at a higher temperature. This can be good or bad depending on your situation; the room temp will be higher while the stove is running and the mass temperature will charge more quickly. If you continue to burn the stove, the mass temperature will continue to rise and therefore store more energy/heat. This will extend the amount of time the house stays in/above the "comfort zone." As long as the room doesn't get uncomfortably hot while the stove is burning, you probably won't need to increase the mass.
The mass in a RMH has one singular purpose: Stabilize temperature.
Compare a low-mass box stove to a RMH. The box stove will keep the room at a comfortably warm temp while it's burning but cool off quickly. If you burn the stove really hot the room will get too hot and then cool down as soon as the fire goes out. Conversely with a RMH, it takes some time for the mass to heat and cool which has a moderating effect on the temperature.
Even with the same amount of heat/energy released from each stove, the box stove will be hotter and heat the room more quickly (and cool off much more quickly) while the RMH will be initially cooler but stay warm for longer. The more mass in the RMH, the more pronounced the effect.
So, ask yourself a few questions:
Does the house tend to get too warm while the stove is running and cool off too quickly? If so, you need more mass.
Does the stove barely heat the space to a comfortable level while burning but also able to hold that temperature for a while after the fire goes out? If so, you need more BTU's (bigger rocket).
Does the stove barely heat the space adequately and cool off too quickly? If so, you need more BTU's and more mass.
TexasGonzo: Sooooo glad I found this site! Its always rewarding to find such a super group of folks! To any and all, feel free to PM me anytime. Thanks for having me!
Mar 11, 2019 18:56:41 GMT -8
jlmtech: GADGET: CONSIDER USING A JET PUMP INSTEAD OF A BLOWER FAN TO INDUCE DRAFT; NO CLOGGING.
Mar 26, 2019 8:19:28 GMT -8
michaelegan: i am unable to open the sketchup files on my mac. I used sketchup a few years back but apparently the company now requires a subscription. does anyone have any advice/instructions on how to use the program or how to view pictures without spending money?
Aug 20, 2019 18:41:48 GMT -8
mannytheseacow: michaelegan: download AutoCAD student version for free... import .SKP
Aug 23, 2019 13:33:44 GMT -8
topbaza: hi everyone, been searching all over net and this is were i need to be i think!!
Sept 28, 2019 6:16:25 GMT -8
anounaki: Hi, why I cant upload photos when I make new tread to this forum?
Feb 28, 2020 2:09:40 GMT -8
ahansen: photos under 1 mb not possible?
Jun 4, 2020 0:09:21 GMT -8
belgiangulch: Photo's are possible. They must be downloaded elsewhere and the image url (adress) is copyied.
Sept 14, 2020 7:26:15 GMT -8
belgiangulch: While creating a thread click on the small picture in the banner above the reply. A box pops up, paste the image url in the box. Pay no attention to the huge list of numbers and such.When you finish and hit reply your post with pictures will come up.
Sept 14, 2020 7:29:27 GMT -8
deadstarsstillburn: Hi there. I was directed this way by folks on the Permies.com website and am hoping I can get some information on how a total newbie can get started designing, siting, building, and not-dying-in-a-horrible-house-fire with a new RMH in a 160-year old home
Oct 21, 2020 6:52:10 GMT -8
deadstarsstillburn: The people over there recommended either a 6" batchbox or an 8" J-tube. I don't know what those are but am going to try to figure that out. What I need is a blueprint that I can scale to fit the need for my house. I have something likne 5000 square feet
Oct 21, 2020 6:53:00 GMT -8
deadstarsstillburn: but I do not need to heat all of it by any means. probably only need to heat half of that, maybe less.
Oct 21, 2020 6:53:15 GMT -8
deadstarsstillburn: moreover, the house has 3 storeys (large attic) so I assume if I get very efficient heating on the ground floor, that will go a long way toward heating the upstairs as well, no?
Oct 21, 2020 6:53:59 GMT -8
BenAlexanderT: Happy new year everybody. I wish you the best
Dec 31, 2020 15:06:14 GMT -8
Solomon: Anybody in Southern Oregon, in Jackson or Josephine counties?
Jan 16, 2021 21:54:43 GMT -8
gnomedome: i realsie this is from 2009
Apr 14, 2021 8:30:44 GMT -8
gnomedome: i realize this is from 2009 id love to see the photos from this ..as im looking to build a sauna soon similar to this .... if anyody sees this post email@example.com..... the photos in this post did not show up
Apr 14, 2021 8:32:00 GMT -8