Central air conditioners are one of the most energy intensive appliances in the home. Using a programmable thermostat to automatically control the cooling schedule can avoid wasting energy, increase comfort and save you money. So what about when you're going to be away from home on vacation for more than a week or more? Should you turn the AC completely off, or just turn the temperature up so it runs less often?
One important factor to consider is humidity. If the forecast includes a chance that the temperature and humidity are going to reach tropical levels, mold and mildew could be a concern if the windows are closed. Remember, an air conditioner doesn't just cool the air, it removes moisture. Turning the thermostat up 10 degrees will enable the AC to turn on every occasionally and keep humidity levels in check.
Have a smart thermostat? Some thermostats like the Nest® include a phone app that will let you monitor the temperature and humidity in your home while you're away. If the temperature and humidity get too high, you can simply turn on the AC remotely while your away.
If excess humidity is not a concern and you plan to turn off the air conditioner while you're away, it's also a good idea to close the drapes and blinds on all windows that are facing sunlight during the day.