@Tracey694 For this particular guest, you can "check" on them and ask if they are enjoying their stay. If the conversation goes well, then you can request that they turn off the AC when they leave the property.
It needs to be made clear to your guests that they must turn off or adjust the air conditioning when they are not in the accommodation. Put this information in your AirBnB description and in your house rules. Post a friendly reminder at the door of the property. Guests may feel entitled to waste resources or are accustomed to hotels.
We installed Nest thermostats in our properties. We can set the thermostat to a temperature range or a schedule, and we are able to control it remotely. If we observe that a guest has left the property, we can check the thermostat app from our phones and make an adjustment if the AC or heat is set too low or too high. Also, the thermostat can be scheduled to run the AC or heat at a certain economical temperature during daytime hours where the guests are usually away and readjusted to cool or warm the property when guests would be returning for the evening.
