Just a quick shot, its just starting to open. Day time temps in my terrarium are in the low to mid 70's and night time temps are in the mid 60's. During the summer I would set the A/C to 75 during the day and 62 at night and that would keep the temps in acceptable range. Now I just keep the heat for that room lower than the rest of the house and so far so good.
And as Socratic said, air circulation and moisture are key. These can be achieved with fans and misting. The main thing that you should consider is will your current conditions be good for the orchid or will the conditions required for the orchid be good for the other inhabitants (i.e plants, fauna, yourself)