I have recently purchased the Soleus portable air conditioner from Sears for my chin (
http://www.sears.com/shc/s/p_10153_12605_04280086000P?prdNo=4&blockNo=4&blockType=G4). Although I haven't gotten it yet (it'll be here thursday) it had great reviews everywhere I looked, and Sears is shipping it for free! Its an air-conditioner as well as a dehumidifer; and uses a refrigerant instead of water (or otherwise it would be pointless!) This particular A/C unit can be a standalone, or can go in the window (depending on if you want the water that gets pulled from the air to collect in a tray or ran through a hose outside your window) Most portable air conditioners do use water, which isn't good because while it is cooling down the room, it's also putting moisture in the air which can be just as bad for a chin as hot temperatures. Any portable A/C will do, just look and make sure it is using a refrigerant, and not water. This one was the cheapest I could find that had good reviews. I think that if you really want a chin this would be fine to use and safe as long as you watch out for A/C units that use water. I hope this helps you out! I searched for a good A/C for about a month before I decided on this one.
On a side note; I'm from Huntsville AL and love it there, you will too!