Another thing to remember is the humidity levels. During this period, dendrobiums do not need a lot of moisture. Very little water will be enough to keep their roots alive. Also keep in mind that their roots constantly need plenty of air circulation so you should place them where there is a lot of fresh air.
Remember, that is based on energy usage, not comfort-levels, which are the purpose of having an air conditioner, in my not-so-humble opinion. Fact: At night, the ideal temperature comfort range for Americans drops to 65 to 72 degrees Fahrenheit (or about 87 degrees if you are my wife).
What is acceptable air conditioner outlet temperature? I have a 1996 Nissan Maxima. It was about 95 degrees today (measured with my own thermometer not what the weather report says), and my air conditioner outlet temperature was reading about 50 degrees. that would be temperature differential of about 45 degrees. I had the fan on second lowest out of 4 settings and on recirculation.