General oxyglossum - cool orchids temp question

[Jeff9]

What is the general day/night temperature C to make oxyglossums and other cool growers thrive?

I am talking about papua guinea and brazilean species, i believe sophronitis require a cool night aswell even tough they are doing fine for me right now at 16C night temp.

If i cannot succesfully chill the air would it be a possibily to cool the water and running the cool water over the plants while running a fan, would this drop the air temperature eventually?

I have been researching alot of cooling and it seems peltier is not effective enough for air cooling, but perhaps it might work effectively enough for water cooling.

Edit: I should note my current temperatures.
Daytime 19-20C
Nighttime 17-18C

This is in winter, this will be problematic in summer so i need a solution.

I believe i can get my nighttime to 15C in my basement, but i am not sure if this is cool enough.

Thanks