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).
When we do home inspections, we expect the temperature at any vent in the house, with the air conditioner in cooling mode, to register 20 degrees below the ambient temperature in the room. Typical supply air temperature directly at the A/C unit air outlet is about 55 deg F dry bulb temperature.