Pearlite/Vermiculite Dome Insulation questions

[Neil2]

If the size is getting too big, you could use 2 inch blanket around the bottom then switch to dry vermiculite/ perlite once the clearance from the inside of the enclosure wall to the dome reaches 4 inches or so.

[EricU]

Originally Posted by BackyardPermaculture

Eric, the concrete blocks will not improve insulation; they will soak up lots of heat if you don't insulate to the same levels as commonly discussed around here.

I am not using the CMU as insulation, but I need to know how much pearlite/Vermiculite insulation I need between the inner face of the CMU and the outer surface of the oven dome. 4"? 6"? More?

As this effects my overall oven building size.

Originally Posted by BackyardPermaculture

Just remember that blanket/wool insulation is most efficient, and that dry pearlite/vermiculite is more efficient than when mixed with cement. But a ton of concrete isn't going to keep heat in your dome.

I have access to concrete, CMU, brick and rock so I probably wont be using the blanket style of insulation.

Thanks, Eric

[BackyardPermaculture]

Hi Eric,

I have access to concrete, CMU, brick and rock so I probably wont be using the blanket style of insulation.

Cool - but none of those masonry materials is much of an insulator, so you still need something like dry vermiculite and/or a blanket. Somewhere on here, James has statistics on how much of each you need. The blanket is much more efficient, so if space is an issue that's the way to go. My own setup is 4 inches of rockwool blanket on top, and on the sides I've got 2 inches of wool and 2 inches of dry vermiculite - but I haven't finished curing yet so can't vouch for performance.

Just keep searching these forums and you'll find lots of info on what various people have tried.

Cheers,
Mick

[EricU]

Originally Posted by BackyardPermaculture

Hi Eric,


Cool - but none of those masonry materials is much of an insulator, so you still need something like dry vermiculite and/or a blanket....

Cheers,
Mick

I dont plan on using the CMU as insulation, and that is why I was asking about how much Vermiculite.

Thanks again, Eric.