nacho
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Post by nacho on Nov 24, 2023 10:20:50 GMT -8
Hello my name is Nacho, i am building a BBR 8 in my House. It is a new construction, and the idea is building the core with the main bell and 2'30 metres of bench which is 20cm (8") below. Everything is straight, and there are 2 issues: 1. I am going to make an oven on the top of the firebox, with refractory slabs on the base and on the top. 2. As the hottest part of the system is the top of the main bell, i am thinking of putting some tubes on the top of the bell (outside the bell) to distribute the heat Air to the rooms. I realize that i cannot load some pictures to feel the thread more Alive. I Will try but in the telephone i cannot see the Button  |
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Post by fiedia on Nov 26, 2023 2:36:12 GMT -8
Welcome Nacho,
To insert pictures in your post, you need to upload them somewhere where they can be reached with an URL address (like a google drive). Then, inside your post, you click on "insert image" just above this box and copy the URL in the dialog box.
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nacho
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Post by nacho on Dec 8, 2023 2:53:49 GMT -8
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Post by fiedia on Dec 8, 2023 4:13:38 GMT -8
Looking at the pictures, there are some details I can not precisely see: Is the floor channel under a layer of bricks or in contact with the fire?
Is there a channel under the firebox between the right and left sides of the firebox? Do you have openings for cleaning bell both sides of the firebox?
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nacho
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Post by nacho on Dec 8, 2023 7:11:09 GMT -8
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nacho
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Post by nacho on Dec 9, 2023 9:58:00 GMT -8
Looking at the pictures, there are some details I can not precisely see: Is the floor channel under a layer of bricks or in contact with the fire?
Is there a channel under the firebox between the right and left sides of the firebox? Do you have openings for cleaning bell both sides of the firebox?
I have build an opening from both sides to clean the bell. The floor Channel IS not possible to be in contact with fire, IS It a Big issue? Also ther IS a connexion from both sides of the bell but between the riser and the oven. Thanks for your help |
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Post by fiedia on Dec 10, 2023 0:02:25 GMT -8
I guess the air provided by the floor channel will be cooler than if in direct contact. peterberg is certainly able to tell you if it is a problem for the combustion.
The floor channel nozzle degrades over time due to corrosion. You may have to replace it within few years. In that case, you will have to cut the brick layer. It might be easier to do it before the firebox ceiling is built.
It looks like you are building the bell against the house wall. If it is the case, I would insulate as much as possible between the house and the bell walls. The purpose is to get more heat towards the inside of the house. You could also fill up the right handside of the firebox between firebox and bell walls. Using bricks or concrete would increase your thermal mass and provide heat for a longer time.
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nacho
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Post by nacho on Dec 10, 2023 1:01:48 GMT -8
I guess the air provided by the floor channel will be cooler than if in direct contact. peterberg is certainly able to tell you if it is a problem for the combustion.
The floor channel nozzle degrades over time due to corrosion. You may have to replace it within few years. In that case, you will have to cut the brick layer. It might be easier to do it before the firebox ceiling is built.
It looks like you are building the bell against the house wall. If it is the case, I would insulate as much as possible between the house and the bell walls. The purpose is to get more heat towards the inside of the house. You could also fill up the right handside of the firebox between firebox and bell walls. Using bricks or concrete would increase your thermal mass and provide heat for a longer time.
I Will isolate between the bell and the House with ceramic blanket on the bell surface and sand in between the blanket and the House wall. It IS ok? Filling Up the right handside between the firebox and Bell Will make me have lower temps in the oven? Ther IS a photo of the BBR now. Thanks!!! drive.google.com/file/d/1rUh2jTPrF6VMlQGnVngLwbOkmvlNGMT3/view?usp=drivesdk |
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Post by fiedia on Dec 10, 2023 6:33:29 GMT -8
Yes, the thicker the better. Using vermiculite or aerated concrete is cheaper. Rock wool and glass wool may stink in case the bell gets too hot.
No, the heat source of your oven is the firebox. The gas around the oven will be colder than the oven itself. If you want to get higher temperatures inside the oven, insulate the right and left sides as you did for the firebox.
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nacho
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Post by nacho on Dec 12, 2023 0:39:05 GMT -8
ok, that is very interesting, i'll isolate the oven too, you say the sides but not the top.
also i can manage to pour vermiculite between the wall and the bell.
Thank you very much!!!
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Post by fiedia on Dec 14, 2023 10:54:18 GMT -8
It would be better to insulate the top too. But it would be difficult to clean the ashes if you put wool on top of the oven. Unless you put a hard layer on top of the wool.
I would just put a second layer of bricks or a mix of vermiculite with a little clay.
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nacho
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Post by nacho on Dec 18, 2023 5:13:14 GMT -8
Hello again, between the ceiling and the riser i will keep a space of 30cm. i am doing the same ceiling as Peter did in Mallorca.
On the top of the closed rocket (outside the rocket) i am planning to put some tubes with fans to redirect the heat to the farthest places of the house. I was thinking about PVC's tubes, but it is not very healthy with heat. What are your recommendations?
fot the Bench we will put some ceramic tiles with holes like this:
in the holes it will be a mix of sand and clay. it is ok?
I have made some math and the total surface the ISA was nearly 8'5 m2, so it is less than the 9'4 max isa. it means that the exhaust will be hotter?
Another question is about the coating, as we finish the structural rocket, how do you manage to make it beautiful and coating the thing but with something strong, avoiding cracks?
Thank you for your answers!!!!
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Post by independentenergy on Dec 18, 2023 5:21:08 GMT -8
you can avoid cracks by building two "skins", one in refractory then a soft contact material and then the second skin which can be bricks, tiles or other.
this way you won't have cracks on the surface
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nacho
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Post by nacho on Dec 18, 2023 8:48:32 GMT -8
you can avoid cracks by building two "skins", one in refractory then a soft contact material and then the second skin which can be bricks, tiles or other. this way you won't have cracks on the surface Hello! I mean in the finishing skin, searching i have found people using linseed oil, but i have not found much more info. |
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Post by fiedia on Dec 19, 2023 7:31:21 GMT -8
It is usually done with dedicated flexible aluminum hoses. PVC may melt down. You will need a fan to create an air flow. I am not sure you will get much heat. I got good results with the pipes just on to of a closed fireplace.
It is better to use plain bricks. holes will not store heat. Filling them up with clay will bring more thermal mass. always mix sand with clay because pure sand is not conducting heat that well.
Not much. I would not worry.
You can use sand / clay mix. Make some trials on a glass plate with different mix: 1 clay /2 sands, 1/3, 1/4. Let them dry preferably in the sun. Choose the mix that has the most sand but still do not loose particles when slightly rubbed, and that does not crack.
Put a first layer 5 to 10 mm thick of coarse sand + clay. Press a high temp fiberglass mesh onside the wet layer. Finish with a thinner layer of sift sand. Press well the finish layer.
It should hold without cracking. And if it does not, you can remove and redo. Clay is reusable and cheap.
I have seen it done with straw instead of a mesh. Did not try it.
Choose precisely the color of your sand.
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