Rocket Mass Heater in a yurt

[hierony]

Zelig,

I did a quick internet search, and everything I found was vague in terms of felt thickness. I have however read that some people's stay-overs in mongolia have been in uninsulated yurts in which one could find many direct holes to the cold outsides Who has what quality/quantity of insulation is understandably variable.

I need to double check, but I believe that comes from Paul King's book, which is in a stack of books somewhere... A quick summary of what I remember off hand: the mongolians, being nomadic shepherds, had lots of sheep and thus wool to make lots of felt. Not being farmers, they didn't have cotton for canvas/liners. They'd use the felt, layering up during the winter to hold in more heat/protect against the winds. I think he said the felt was 1" thick and they'd use 5 or more layers during the coldest times, with some being older felts. But I suspect the 1" thickness may be slightly exaggerated/inconsistent. With a cotton cover, canvas, maybe some tyvek, and your two layers of 1/2" felt you should be well ahead of them.

One thing to consider: you can seal up your yurt a bit better than old school traditional yurts. They have a crown ring in part to allow smoke from an open fire to escape--you get to use stove pipe and not have a giant opening in your roof. Also, your fuel (wood?) is up to two times more energy dense than dried camel/pony/sheep dung...