One way to help prevent mold from developing in your vacant home is to control the indoor relative humidity. You can accomplish this and still manage your energy costs by using a programmable thermostat. Program your air conditioner to run at 72 degrees for just two hours before sunrise and at 88 degrees the rest of the day. If your air conditioner does not have a programmable thermostat, set it to 80 degrees. Thermostats in condos and apartments should be set at 77 degrees to make the air conditioner run enough to provide significant dehumidification.