I just realized I have about 15 feet of old copper AC line left over from an old AC unit that we recently replaced. I'm trying to figure out what I can do with it. I'm thinking some sort of wort chiller. There are two separate 15 foot lines. One looks to be 3/8 and the other looks to be about 1 inch. Since both lines have been used for AC before they have had some crazy chemicals, freon or whatever, in them so I'm not even sure if they are safe to use or not. With proper cleaning I'm thinking they would probably be ok though .I also have another coil of about 20 feet of 3/8 and two 20 ft or so coils of 1/4. I'm thinking the 1/4 stuff might be to small to use though. Oh, and I also have a wort chiller that I already made out of 20 feet of 3/8. I'm thinking some kind of double chiller, one that fits inside of the other and can be used separately or together. Or one could be used as a prechiller. The one inch line had me thinking about a counter flow chiller or something too. Any suggestions? What should I do with all this copper?