This is pretty involved, so try and keep up.
I went down to the convenience store, and picked up a buy-and-sell paper, I looked up dehumidifiers in the index, then I read the ads for used dehumidifiers.
Seriously, it's that easy. I paid $50 (CDN) for it.
I don't know exact numbers, but R12 has a higher heat capacity. Only problem is it's illegal now, so if you let it out

, it has to be recharged with one of the newer "friendly" gasses.