I have a screened in patio with tall walls on all four sides, so not much breeze. In the summertime here in Florida, a fan isn't enough to do the trick. Every year I've considered purchasing a swamp cooler to keep a small area cool outside (maybe 400 sq ft). Has anyone had success with these? Any recommendations? I looked at a Big Ass Fans version (its fans are awesome) but the company's poor return policy has prevented me from purchasing.