It is generally not cheaper to run your AC continuously all day than to adjust your thermostat when you are away from home. However, turning the system completely off may not always be the most efficient choice, especially during very hot weather. A better approach is usually to raise the thermostat while you are away and lower it when you return. This reduces how long the AC needs to run while still keeping your home from becoming excessively hot. Your home’s insulation, outdoor temperature, AC efficiency, and thermostat settings can all affect how much energy you use.
Why Running AC All Day Can Increase Energy Use
An air conditioner uses electricity whenever it is actively cooling your home. If you keep your thermostat at the same low temperature throughout the day, the system may cycle frequently or run for extended periods to maintain that temperature.
The warmer it is outside, the more difficult it is for your AC to maintain a cool indoor temperature. During Maryland summers, prolonged periods of high heat can cause an air conditioner to operate for much of the day.
This does not necessarily mean that every minute the AC runs is wasteful. The system needs to operate to maintain a comfortable temperature. However, maintaining a very low temperature while nobody is home can use more energy than necessary.
Should You Turn the AC Completely Off?
Turning the AC completely off while you are away can reduce cooling energy use, but it may not always be the best strategy. If your home becomes extremely hot, the AC will have to work harder once you turn it back on.
A more practical option is to raise the thermostat several degrees when you leave. For example, someone who normally keeps the thermostat at 72°F might choose a higher setting while away and return it to their preferred temperature when they get home.
A programmable or smart thermostat can make these adjustments automatically based on your schedule.
What About Running the AC at Night?
Running your AC primarily at night can use less energy if you are comfortable allowing your home to become warmer during the day. However, nighttime temperatures and humidity levels vary, so the savings depend on your specific circumstances.
If your home becomes too hot during the day, reducing the temperature significantly at night may require the AC to run for an extended period. Instead of focusing only on nighttime operation, it is usually more effective to manage your thermostat based on when cooling is actually needed.
Other Ways to Reduce AC Energy Use
Thermostat settings are only one part of cooling efficiency. Clean filters, proper airflow, adequate insulation, and regular HVAC maintenance can all help an air conditioner operate effectively.
Using ceiling fans, keeping blinds closed during the hottest part of the day, and reducing unnecessary heat from appliances can also help your home stay comfortable.
Conclusion
Running your AC all day at a constant temperature is generally more expensive than adjusting the thermostat when you are away. Rather than turning the system completely off, consider raising the temperature during unoccupied hours and lowering it when you return. A properly maintained and efficiently operating AC system can also help manage energy consumption during Maryland’s hot summers.
