michael beyer wrote:
woah! this seems cool! so it is the air in the jars that acts as insulation?
Yes, it is. Insulation is actually a series of heat exchanges. Hot air meets cold surface, some of the heat bleeds off. Next air pocket, more heat loss. That's why goose down is such a great insulator: millions of tiny "beer bottles" to trap the heat. This bottle thing is even used by many to insulate the base of
cob pizza ovens. I used wine bottles at the base of my
oven which got to 900 degrees but i could put my hand on the base. However, it is not the best insulator to use because it only presents one heat exchange. So i worked
straw and such into the
cob to create more air pockets. It's why insulated sleep pads for backpacking are so much better R value than non-insulated. This bottle floor is more like the latter. Still inspiring though.