We put a mister on our lanai [that's a back porch to you Yankees] a while back and were amazed at the difference. It cools it down from upper 90's to comfortable in about 5 minutes. That 34 ft 17 nozzle unit came from Sam's and only cost 20 bucks. This week Suzy found a 10 foot model at Lowe's,[Orbit / ArizonaMist] for about 11 bucks. I put it up on the awning this morning and it's great. This 11 bucker is a stand alone unit, if you want to connect 2 for 20 feet you have to buy a more expensive version. [At least at Lowe's]. We just need a faucet splitter so we can run city water into the coach and another short hose to the mister. Judging from the popularity of these things recently and the heat wave covering the entire country, these will be all over the place soon.
http://www.orbitonline.com/mist-cooling/