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Post by paganodimelito on Oct 18, 2024 13:51:05 GMT -8
Thanks peterberg for another great development! The most recent description of the door frame I have found is at donkey32.proboards.com/post/39881/thread. Can you confirm this is the way to go? Is the air passage through the door frame what controls the maximum burn rate? Somewhere you mentioned stacking the wood leaving a 5 cm gap between the end of the wood and the wall with the port. In the case of a sidewinder, would it be OK to recess the last 2xB of the side wall by 5 cm (maybe with a small step in the far end), in order to make it easier to stack the wood leaving the needed clearance in front of the port? would you omit the slanted floor in this part of the side wall? Planning to build a 150mm stove with a bench, with the chimney going through 2 floors (7m) uninsulated plus 3m insulated through the attic. |
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Post by belgiangulch on Oct 18, 2024 14:04:27 GMT -8
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Post by peterberg on Oct 19, 2024 6:35:55 GMT -8
The most recent description of the door frame I have found is at donkey32.proboards.com/post/39881/thread. Can you confirm this is the way to go? Is the air passage through the door frame what controls the maximum burn rate? Yes, it is the way to go. And no, the air system is NOT what controls the maximum burn rate, the proportions of the core itself are the key. Somewhere you mentioned stacking the wood leaving a 5 cm gap between the end of the wood and the wall with the port. In the case of a sidewinder, would it be OK to recess the last 2xB of the side wall by 5 cm (maybe with a small step in the far end), in order to make it easier to stack the wood leaving the needed clearance in front of the port? would you omit the slanted floor in this part of the side wall? I don't know what you are asking, but just to be sure: the port shouldn't be in the far corner. Instead, it should be half of the riser to the front and is centered in the riser. For reference: it's done similar as the normal sidewinder, which is on the batchrocket site. The port of the Shorty sidewinder is a bit more to the front than the normal one since the Shorty's riser is wider. Planning to build a 150mm stove with a bench, with the chimney going through 2 floors (7m) uninsulated plus 3m insulated through the attic. Can be done, provided it's done exactly to specs. Start building and ask questions as you go, preferably accompanied by pictures. |
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Post by paganodimelito on Oct 20, 2024 7:35:16 GMT -8
Somewhere you mentioned stacking the wood leaving a 5 cm gap between the end of the wood and the wall with the port. In the case of a sidewinder, would it be OK to recess the last 2xB of the side wall by 5 cm (maybe with a small step in the far end), in order to make it easier to stack the wood leaving the needed clearance in front of the port? would you omit the slanted floor in this part of the side wall? I don't know what you are asking, but just to be sure: the port shouldn't be in the far corner. Instead, it should be half of the riser to the front and is centered in the riser. For reference: it's done similar as the normal sidewinder, which is on the batchrocket site. The port of the Shorty sidewinder is a bit more to the front than the normal one since the Shorty's riser is wider. Ok, let me explain myself better with a drawing.  First is the standard layout, second the sidewinder, third what I'm proposing. My fear with the sidewinder is that it would be difficult to stack the wood without blocking the port. By recessing the wall around the port by 0,5xB and stacking the wood straight, you would automatically get a gap in front of the port. This is just an Idea, I'm not planning to implement it in this build due to space constraints. |
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Post by paganodimelito on Oct 20, 2024 8:39:00 GMT -8
Planning to build a 150mm stove with a bench, with the chimney going through 2 floors (7m) uninsulated plus 3m insulated through the attic. Can be done, provided it's done exactly to specs. Start building and ask questions as you go, preferably accompanied by pictures. I'm constrained by the dimensions of the wall against witch I'm building, with doorways on both ends and a column protruding almost at the beginning. this is what I've come up with:  As you can see, I would like to move the port of the sidewinder even closer to the door... do you think this could work or would it create too much of a dead space in the back end of the chamber? The only other option I can see is extending the front door of the stove out of the bench. That would be a bit annoying for the doorway, but feasible as a last resort. Accounting for 50% of the uninsulated indoor part of the stainless steel chimney, plus the bench, the total ISA is 5.8 m2, slightly more than the recommended 5.3 m2 for the 150 mm batchbox. The total elevation of the smokestack from the floor is 10,8 m, with six 45°-bends, the total length is 12 m. The minimal cross section within the bench is 5xCSA. If the draft isn't satisfactory, I could insulate some sections of the indoor chimney. On the other hand, if the draft is plentiful, I'll paint some sections of the indoor chimney black to increase radiative heat transfer. I'll put two cleanout ports at the beginning and at the end of the bench. The latter could also be used to prime the chimney for cold starts in the mid-seasons. I'm pondering if I should create channels under the core and up between the core and the wall, feeding hot air in a "ventilated white oven / dryer" on top of the core. |
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Post by peterberg on Oct 24, 2024 12:05:06 GMT -8
First is the standard layout, second the sidewinder, third what I'm proposing. My fear with the sidewinder is that it would be difficult to stack the wood without blocking the port. By recessing the wall around the port by 0,5xB and stacking the wood straight, you would automatically get a gap in front of the port. This is just an Idea, I'm not planning to implement it in this build due to space constraints. The second possibility is correct, the third isn't, in the sense that it's untrodden territory. So you won't know whether this is performing just as well as the tested variants. Don't forget the slanted sides of the firebox, also a piece at the far end of the port. It's been tried during summer to load fuel in front of the port while the core was running flat out. It handled that without a problem, no smoke or whatever. |
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Post by peterberg on Oct 24, 2024 12:16:46 GMT -8
As you can see, I would like to move the port of the sidewinder even closer to the door... do you think this could work or would it create too much of a dead space in the back end of the chamber? The only other option I can see is extending the front door of the stove out of the bench. That would be a bit annoying for the doorway, but feasible as a last resort. Again, this possibility isn't tried and tested, it's better to stick the proven design. I can also see a problem with the direction of the core exhaust, it's directed to the wall right opposite it. Better to have the door in the longer wall and have the core exhaust point to where you want it to go. Accounting for 50% of the uninsulated indoor part of the stainless steel chimney, plus the bench, the total ISA is 5.8 m2, slightly more than the recommended 5.3 m2 for the 150 mm batchbox. In that case, with an oversized bell, you'll need to install a bypass for sure. The chimney could be a problem, with 6(!) 45 degree bends. Pipes under or beside the core to transport hot air, need to be counted in the total allowable ISA. |
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Post by paganodimelito on Oct 25, 2024 1:27:05 GMT -8
As you can see, I would like to move the port of the sidewinder even closer to the door... do you think this could work or would it create too much of a dead space in the back end of the chamber? The only other option I can see is extending the front door of the stove out of the bench. That would be a bit annoying for the doorway, but feasible as a last resort. Again, this possibility isn't tried and tested, it's better to stick the proven design. I can also see a problem with the direction of the core exhaust, it's directed to the wall right opposite it. Better to have the door in the longer wall and have the core exhaust point to where you want it to go. Unfortunately I have to work with the space I have. One way to respect the nominal core layout is to feed the inlet air through a tunnel under the beginning of the bell, and the wood through an airtight insulated door at the back of the burn chamber (will make a drawing later). I see no way I can avoid the 90° turn in the core exhaust within my space constrains (maybe a straight core with the door on the side...?) Accounting for 50% of the uninsulated indoor part of the stainless steel chimney, plus the bench, the total ISA is 5.8 m2, slightly more than the recommended 5.3 m2 for the 150 mm batchbox. In that case, with an oversized bell, you'll need to install a bypass for sure. The chimney could be a problem, with 6(!) 45 degree bends. Pipes under or beside the core to transport hot air, need to be counted in the total allowable ISA. The actual bell is 3,67 m2 before the beginning of the chimney. I have added 50% of the uninsulated chimney as you suggested in a previous BBR build that turned out perfect. In theory, considering a chimney temperature of 100°C (witch is conservative because of the smaller bench) I calculated a total buoyancy force of 26 Pa and a friction loss of 12 Pa, that leaves me with a draft of 14 Pa. In practice, if it doesn't work, I'll insulate more of the chimney. Meanwhile I have updated the batchbox calculator to the Shorty, based on dvawolk 's sketch donkey32.proboards.com/post/39715/threadYou can download it here: www.dropbox.com/scl/fi/ojiluv3a95pgkk2bl5gpa/shorty-calculator.ods?rlkey=ceeeyfh9drl35lpzmwa2odrip&st=rhsrhff5&dl=0 |
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Post by paganodimelito on Oct 25, 2024 14:43:11 GMT -8
Ok, so here are the drawings of the two variations I was talking about this morning:  This one has all dimensions to specs for the sidewinder. I would load it from the vermiculite door on the back end, the air inlet frame would be completely encased in the bench, with a tunnel for the air. double glass on the side to be able to see the fire. The issue of the 90° turn right after the exit port remains.  This variant is a straight core, with a double glass door on the side... too much metal for my liking, but it would allow for a more compact overall construction In both cases the ISA is slightly reduced compared to previous calculations. |
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Post by peterberg on Oct 26, 2024 4:59:02 GMT -8
Just an observation: you are trying to squeeze the core in a space that's actually not suitable. What about building it as a (tried and tested) sidewinder in front of the column?
The first drawing of the post above shows a measurement of 80 cm from the wall. The column is about 20 cm deep, which leaves you with 60 cm. The depth of a 150 mm sidewinder's firebox is 43 cm, plus the back wall and the door frame which would make about 55 cm total depth. Another 5 cm for insulation between the column and the firebox and it'll fit just beautiful. A left-handed sidewinder would spew the gases directly in the right direction.
You could even opt for a slightly shorter firebox, depending on the length of your fuel. In general, length of the fuel plus 10 cm is close to ideal.
The above sounds like a good alternative to me.
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Post by paganodimelito on Oct 26, 2024 11:21:56 GMT -8
Just an observation: you are trying to squeeze the core in a space that's actually not suitable. What about building it as a (tried and tested) sidewinder in front of the column? The first drawing of the post above shows a measurement of 80 cm from the wall. The column is about 20 cm deep, which leaves you with 60 cm. The depth of a 150 mm sidewinder's firebox is 43 cm, plus the back wall and the door frame which would make about 55 cm total depth. Another 5 cm for insulation between the column and the firebox and it'll fit just beautiful. A left-handed sidewinder would spew the gases directly in the right direction. You could even opt for a slightly shorter firebox, depending on the length of your fuel. In general, length of the fuel plus 10 cm is close to ideal. The above sounds like a good alternative to me. Thank you Peter for your patience! After countless hours fiddling with the drawings I realized I was overcomplicating more and more, and I started from scratch... I soon came to exactly the same conclusion, and I was about to ask you about shortening the firebox (most of my fuel is already cut short for another stove). here it comes, in all its simplicity:  |
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Post by paganodimelito on Oct 26, 2024 11:48:56 GMT -8
another question is about how precise I need to be: the Base dimension is 108,5 mm. Could I round it up to 110, that corresponds exactly to the size of my firebricks?
They are very hard, factory made to exaclty 220x110x55 mm. I'm planning to dry-stack them and surround the whole core with cob mixed with vermiculite grains.
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Post by peterberg on Oct 26, 2024 12:08:10 GMT -8
another question is about how precise I need to be: the Base dimension is 108,5 mm. Could I round it up to 110, that corresponds exactly to the size of my firebricks? Yes, you can. The base figure would be slightly larger but more bricks can be used as is. As long as the proportions are correct, the thing will do what it is built for. Mark that the port is a little bit different: 2.1B instead of 2.2B. This is done exactly to make more uncut bricks possible. They are very hard, factory made to exaclty 220x110x55 mm. I'm planning to dry-stack them and surround the whole core with cob mixed with vermiculite grains. I'd think it to be better to use some mortar between the firebricks. Maybe even just clay and fine sand, otherwise it would be nearly impossible to pack the clay and vermiculite around it. By the way, perlite would be better in this respect, vermiculite tend to absorb enormous amounts of water. And it's hard to get out by just drying as well. |
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Post by paganodimelito on Oct 26, 2024 14:07:52 GMT -8
Yes, you can. The base figure would be slightly larger but more bricks can be used as is. As long as the proportions are correct, the thing will do what it is built for. Mark that the port is a little bit different: 2.1B instead of 2.2B. This is done exactly to make more uncut bricks possible. Do you mean that that .1 is accounting for the thickness of the mortar between the bricks and I don't need to cut a notch in the brick? then the box height should be 3.15B... I'd think it to be better to use some mortar between the firebricks. Maybe even just clay and fine sand, otherwise it would be nearly impossible to pack the clay and vermiculite around it. By the way, perlite would be better in this respect, vermiculite tend to absorb enormous amounts of water. And it's hard to get out by just drying as well. Yes, doing some trial mixes I've noticed the vermiculite even crumbles and looses a big part of its volume... I don't think I can get hold of a big bag of perlite at the moment. It might be better to make a fiber reinforced cob wall with a gap to be filled with dry vermiculite, or just a layer or two of ceramic blanket and the cob strait on top By the way, here is a cross section  What do you think about the ceramic glass right on top of the core? I imagine the riser would make the glass to hot to cook, so I'm planning to put a double layer on the riser and a single layer in the area just outside the exit port, followed by a refractory slab for lower heat cooking. When not cooking I can lay a vermiculite board on top of the glass to send more heat down the bench |
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Post by paganodimelito on Nov 20, 2024 12:59:38 GMT -8
I've gathered the materials and built the door frame Here are some pictures: photos.app.goo.gl/n3GzZAeZ8ZGSkKVw7I was hoping to have the complete door by tonight, but I shattered the glass...  Does anyone here have experience cutting refractory glass? I could use some advice BTW, peterberg, could you change the thread title to something more descriptive? Something like "150 mm Shorty Batch Box with cook top and bench" |
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