I found two misting towers at a home improvement store that work quite nicely for misting outside orchids. I live in Florida and my orchids are hanging inside a screened in porch. They get the appropriate amount of light, but the temps at this time of year can be brutal. The misting towers are made by Aeromist and are suppose to be for cooling an area on a porch. I have two of them hooked up to a garden hose with a timer. They seem to work great. The home improvement store price is significantly cheaper than buying direct from the mfg. Unfortunately the store doesn't have the offered accessories namely inline filters and replacement nozzles. I ordered them directly from the mfg. I hope somebody get some use out of this post and here's the link
Aero Mist Misting Systems
Regards