Miltoniopsis temp control

[Polypodiaceae]

I have two miltoniopsis, which are a couple years into my growing environment. They have been gradually getting more brown spots on the leaves, though they continue to bloom each year. Research here has made me think that my growing environment is too warm - indeed, Seattle's summers have become more warm more often, and this 1920s building holds heat.

If my diagnosis is believable, is there anything to do beyond finding them a new home or running the AC all the time (which I won't do)? I really like my Henry Jackson "Wild Thing" but in a rented studio etc. my ability to change conditions is limited and that might be the final answer!