I know they make refridgerators that run on propaine as well as k2 and that they somehow use a small flame to do the cooling like what is in a lot of RVs and such but I dont understand all the workings of them. I was wondering if anyone here knew enouph about them to know how they work and how realistic it would be to build refridgeration that would use the same principals if SHTF. I figured if it can be done with these fuels then it may be able to also be done with wood or tallow or some such. Seems to me that if someone could figure out how to do this and make it work well for something like a walk in size cooler, especialy if it could freeze ice, they could be extreamely popular if SHTF. How much would a glass of iced tea or ice cream be worth on a summer day when its over 100 out when no one has ice, refridgeration or air conditioning anymore? Not to mention being able to cool and store fresh meats and milk and so on rather than haveing to can all of the stuff or use it and use it warm right away.