The basic concept of how the outdoor misting fan works is the exact same concept of how a sweating person on a breezy day is cooled. You see, any type of chemical or physical change requires energy. The energy is either taken in and stored or released depending on what is taking place.
As it turns out the conversion of water molecules from liquid to vapor (steam), uses up heat energy and you can test this out by placing two pots of water on two separate stoves. On one stove turn the heat on and the other one leave off. Now which one ends up boiling?
Who hasn't at some point over the course of the past twenty or so years, on a warm day stepped outside at a nursery or an outdoor dining area at a restaurant and encountered some sort of misting system. I can remember the first time I encountered on years ago.
Well since those early days of expensive, complex and often fickle outdoor misting fan systems, they have gone through several refinements. One of them is newer, far more compact, free standing one fan units that start out with prices as low as around $150.
Simply hook up your garden hose, plug in the cord and away you go! However; be aware before you run right out and order one of these easy to afford systems that they do have their limitations with regards to cooling power.
What this means, is that basically a smaller, bottom of the price range unit would be something that would have to be set up a very short range from the people it's intended to cool. Perhaps a few people sitting close together out on a patio or deck.
So if your cooling plans go beyond that, you're going to have to expand your horizons with regards to what you'll be considering on your shopping list. Now there are some larger more powerful free standing systems and basically the more they cost the more cooling power they deliver.
Now it's very important to keep in mind that the “ambient humidity” of the area that you live in or plan on using your outdoor misting fan in factors in heavily. What this means is that if you live Louisiana, Florida, Mississippi, etc you may want to consider just using a fan. There's already plenty of moisture in the air on humid days.
On the same note: if you live in an arid region your going to get better results from one of these types of cooling units. The basic rule of thumb, is the drier the air is to begin with, the more effectively any outdoor misting fan is going to work.