Just felt the need to clarify what I wrote earlier...
I have a lot of vandas and mounts in my collection so I must mist everyday most of the year. When the really hot temps come (like today at 90!) they'll get misted at least twice.
That's a really good point Sue. I think misting as a topic can be over-generalized. There are lots of reasons to mist ceratin genera (Phals are an example) in dry/hot climates. In cool moist climates the same regimen might cause problems.
I don't do most Dendros or large, "floofy orchids". For me it's minis (like Angraecoides), Masdies, Paphs, and others that crept in somewhere along the line. See my orchid list for complete collection (usually not current.)
Once again, it all boils down to doing what works for you in your particular conditions, whatever they may be. Any advice we read anywhere is going to be very general because everybody grows in different situations with different care regimens.
What are you trying to accomplish by misting? If it's cooling, which is apparently Susanne's goal, fine (but be as careful as she). If it's to raise the humidity, forget it, as you should be misting around the plant to "wet" the air. Wetting the leaves lowers the surface area many orders of magnitude compared to a mist and slows the evaporation process.