Summertime humidity

[WeirdGuySeattle]

Hi - I grow in a greenhouse in the Pacific NW. I get a fair amount of direct sunlight and grow under a shadecloth in the summer months (April thru some of October).

We get about a natural 25-30% humidity in the summer, and this is what my greenhouse ends up (I think) in on a normal summer day (after all the vents open up)

I don't have a hygrometer, but I am pretty sure the humidity gets pretty low in summer. My Catts, Coelogyne, Phal (if they don't get burned) & Oncidiums do well, but I think my other plants suffer from low humidity. I am trying to grow quite a few pleurothallis, and a few mounted orchids.

My greenhouse is freestanding, and I only have a garden hose able to run to it - so preferably I can run something with a resevoir.

Does anybody have any recommendations on a humidity system I could set up? I am not picky about if its fog or mist, but it probably shouldn't be a warming / steam type humidifier.