Al from A&A Cooling & Heating in Apache Junction, Arizona shares the most cost effective thermostat setting. Cooling your entire house takes time because you are cooling not just your own personal self but the walls, glass, interior items, etc. Picking a thermostat setting that you are comfortable with (use 78 as an example) and leaving that setting is the most cost effective. Fluctuating the thermostat while you may be at work or gone for the day is not cost effective. Maintaining a constant temperature without having to “cool down” the entire house daily, etc. will save you money in the long run. While you may be vacationing, you could pick a higher temperature (like 80 or 85) and maintain that temperature throughout your home. Turning off the unit completely is not recommended for extended periods because of the possible damage to interior electronic devices, wood drying out, adhesives/caulking heating up and emitting smells, etc.