|
|
Post by independentenergy on Sept 7, 2024 2:10:48 GMT -8
Hi, I should fill a cavity of a stove between the first skin and the second skin, the material must conduct heat, not be insulating and soft or dust, do you have any ideas? I was thinking of refractory earth dust...
|
|
|
|
Post by josephcrawley on Sept 7, 2024 16:04:20 GMT -8
Sand would fit the bill and has the advantage of being cheap.
|
|
|
|
Post by independentenergy on Sept 7, 2024 21:43:28 GMT -8
sand is cheap, that's for sure...I don't know how it conducts heat though, have you tried it in a similar application?
|
|
|
|
Post by martyn on Sept 8, 2024 0:52:36 GMT -8
What about sand and cement?
|
|
|
|
Post by independentenergy on Sept 8, 2024 1:11:48 GMT -8
I don't want a solid filling to be created it must be either wool (but conductive not insulating) or dust
|
|
|
|
Post by martyn on Sept 8, 2024 3:48:15 GMT -8
Air is an insulator so if you have anything that is loosely packed it will trap air and be insulating, sand mixed with cement at 8-1 will be conductive and fragile enough to easily break up?
Powdered clay might be fine enough to compact and work for you, where I live that would cost me around ten time more than sand and cement but perhaps not where you live.
Maybe very fine, graded, sand would work but again that would also be expensive for me.
|
|
|
|
Post by peterberg on Sept 8, 2024 3:56:41 GMT -8
Hi, I should fill a cavity of a stove between the first skin and the second skin, the material must conduct heat, not be insulating and soft or dust, do you have any ideas? I was thinking of refractory earth dust... Please, don't use anything that's loose and hard, like sand. This will compact greatly over time and the net result will be severe cracks in the outer skin. Using 12 mm superwool works, although ypou might think it's insulating. In fact, it is, but when temperature differences between inner and outer skin are large enough heat will come through anyway. Insulation material won't stop heat transfer, it slows it down. In short: The higher the temperature difference (called deltaT) the less time it will take to come through. Alternative: use cardboard to separate the inner and outer skin, and pull that up during the building process. So you'll end up with an empty cavity. |
|
|
|
Post by independentenergy on Sept 8, 2024 3:58:53 GMT -8
and what I thought Martyn the air in the coarse sand could insulate, that's why I thought of the refractory earth, it costs about double a bag of sand but the price in itself is not prohibitive.
when you say sand and cement do you mean without water just the two components mixed? or do you mean mixed with water then reduced to powder after drying?
|
|
|
|
Post by Dan (Upstate NY, USA) on Sept 8, 2024 4:14:09 GMT -8
Always wanted to make one with that space being steel wool, can compress and expand but conducts heat
|
|
|
|
Post by independentenergy on Sept 8, 2024 4:18:26 GMT -8
but does steel wool contain a lot of air or am I wrong?
|
|
|
|
Post by independentenergy on Sept 8, 2024 22:38:27 GMT -8
Hi, I should fill a cavity of a stove between the first skin and the second skin, the material must conduct heat, not be insulating and soft or dust, do you have any ideas? I was thinking of refractory earth dust... Please, don't use anything that's loose and hard, like sand. This will compact greatly over time and the net result will be severe cracks in the outer skin. Using 12 mm superwool works, although ypou might think it's insulating. In fact, it is, but when temperature differences between inner and outer skin are large enough heat will come through anyway. Insulation material won't stop heat transfer, it slows it down. In short: The higher the temperature difference (called deltaT) the less time it will take to come through. Alternative: use cardboard to separate the inner and outer skin, and pull that up during the building process. So you'll end up with an empty cavity. I was thinking about leaving it empty, the gap between the two skins is about 2cm. Before there was superwool but I think it insulated too much, I couldn't heat the external skin in an acceptable way |
|
|
|
Post by peterberg on Sept 9, 2024 1:26:49 GMT -8
I was thinking about leaving it empty, the gap between the two skins is about 2cm. Before there was superwool but I think it insulated too much, I couldn't heat the external skin in an acceptable way That is leaning towards the cardboard trick, but there's not a world of difference between insulation in the gap or not. What might be a better option then, is a single skin heater using the Mallorca build construction. Has been done multiple times and it's a safe bet. |
|
