Don't ask me why I was perusing the Wheaton Lab's project list as I have neither the time nor the means to get my butt up to Montana, but I was and thought I'd throw out a potentially cool idea for a future project:
I think Paul's idea for a wofati freezer is awesome, but when I saw it on the list the first thing that came to mind was the trompe
In his video lectures, Mollison talks about the many uses of the trompe that go WAY beyond what the wikipedia article discusses and one in particular that relates to the freezer idea. Specifically, the pressure built up in the lower chamber needs to be released from time to time and the byproduct? Ice and very...cold...air!
Why am I proposing this instead of trying it myself and sharing a bunch of photos and info? Several reasons:
1) I don't have running surface water (required).
2) I have limited time and lots of hugel beds to build.
3) I lack an excavator, ants, wwofers or volunteers to help with the backbreaking labor of digging out the channel for a tromp
Regardless, if we ever get our Sepp-style pond/swale setup going, I may just try this out, but in the meantime, I thought it might be something interesting for you tinkerers to ponder.