Controlling temp differential for Phals & Catts in same household room

[jean2]

So my plants are in a spare bedroom- a bit of natural light (more in
the winter, less in the summer- decid tree outside window), and 4
florescent tubes over them- 2 cool white, 2 "daylight".

The question is about temps. I, of course, heat the room in the winter
here in Missouri. Nice temp difference between day and night, maybe 55
night and 73 day. But in the spring/summer/fall, I leave the windows
open and let it go. Of course, it's humid as all get out, and I keep a
fan circulating, but the temps hit the 90's during the day, and may
not even get down into the 70's at night.

I grow mostly Phals and Dends. I'm fairly new, but so far no problems
with either. The Phals rebloom, and I even have a spike under
florescents on a Dendrobium! I'm wondering about long term
consequences- slow growth, etc. I am getting new growth on the
Phals....

What do you all think? Will they all flourish given the proper
humidity and lots of air movement? What will suffer?