Yes, long term maintenance is an issue, but I should be able to print a dozen or so at once, and the printer does not need me to do the work. So if I print up a hundred or so, and finish the out with magnets and contacts, I can stack them on a shelf to use whenever.
The alum isn't actually poison, it just tastes very bitter, so it should repel without killing.
I intend to use an Earth battery on the home, and the walipini (underground greenhouse.
With the heat exchanger, the house should work pretty efficiently, and still breathe enough to be healthy!
:)
That is all pretty awesome. Especially the alum just being bitter.
Yes I liked that myself, LOL! Some of these systems have been running wild in my head for decades.
I just decided that if I had to do the work anyway, I may as well make it all work the way I want!
:D