There were posts mentioning that small AC units can be purchased for 50-100 dollars that would be better/more efficient. I say hats off to the guy for coming up with a solution that can be done for less than that. He doesn't need an AC for a dorm room cooling solution. What he did was about perfect. Not too much money and it did the job adequately. If I only need AC for a brief period of time then I'd rather pay a little for something that doesn't really alter anything else I'm doing than pay around a 100 bucks for something that is going to sit idle for long periods of time. Not only that but when I graduate and get a job I will probably move into a house or apartment that doesn't need any more AC.
I was thinking how for my situation a homebrew AC would be better than a regular AC. If I a regular unit I would use it even when I don't need to. Most of the time the ceiling fans we have are adequate. The times that they are not I would much rather pull out the homebrew rig and cool things off every once in a while as needed. That got me thinking what I would do differently...
For starters I would have the fan blowing on to what I would use to exchange heat. The one in the article was pulling air across it. The second thing I would do is get a cheap heater core from an auto parts store or junkyard instead of copper tube. This way there is more heat exchange. Third I would get a pump and recirculate. I'd keep a water resevoir in an old cooler that I rarely use. Turn the system on and put another tray of icecubes in every once in a while. It would do a better job than the one in the article, it wouldn't be a whole lot more expensive if you get the right heater core and water pump, or get them somewhere cheap, like ebay. I'm already running the fan and the freezer, so I'm only adding the cost to run the pump as needed. Not too bad.
I don't think it's a bad idea. I might do it. If I end up not liking it or not needing it later on, I can always use it for a water cooling set up. Now when I talk to one of my friends about it he mentions that he has an extra Honda CRX radiator. Time to get to work.
I've noticed several design suggestions in your code.