I'm not sure if you're going to go through with using a 10 gal.
But whatever you use, make sure there's air movement
I have a small fan in my setup, but my setup is bigger than a 10 gal in comparison.
Also, you could mist the 10 gal pretty easily. That will keep the humidity up. (If needed)
But I honestly recommend a 20 gal or more. I guess it depends on how many and how big your orchids are though. for instance, I would need something around 30 inches tall for my phal in bloom.