Hi Brett.
Welcome to the forum! How did you hear about us?
I was gonna say what Bird said, but he beat me too it and his answer is much more accurate than mine would've been
What type of telescope do you have?
From Anthony's experiments, it would appear that
at ambient temperature is better, but he usually cools to 0.5deg below ambient, so that by the time he's ready to image it's settled down.
The boundary layer and distortion of the mirror will affect the views both visually and when doing imaging. Obviously it's much more noticable when doing imaging, because you're working at much longer focal lengths (higher magnification).
Non DIY newt imaging people like myself are going to start by just working out what temperature the mirror is compared to ambient, so wombat_in_space is making me a unit that measures the temperatures and sends the data to my laptop. To start with, i'll know when the best time to image is.
Following that, i'll make an active cooler like Birds, to cool the mirror faster so that I can start imaging sooner.