That he is, I grew up for a good part in a logging camp and we'd have died laughing if some one suggested wasting such a valuable resource such as propane!

Now you said you have kids? I'm guessing they have bikes? and a car A/C compressor is rather easy to acquire!

lol no, but on a serious note that is what I will suggest, wind or water to spin it, that or do as they have suggested and get a 12volt compressor, a solar cell (They are dirt cheap now days) and over size the condenser and there you go, and teach the kids to use their brains and not open the door all the time and be quick when hey do need to open it. Oh and a deep cycle, that system put togeather well will last many many many years (The one the guy made at camp with a home made inverter and a standerd compressore has lasted till now and from what I hear going, so thats the real viable option you have, that or pelts but that will consume way more then needed)