When summer hits and the heat drags on for days, it’s tempting to just leave the AC on all the time. But is that actually a good idea? The short answer: It can be — if you’re smart about it.
Why Constantly Turning It On and Off Doesn’t Help
AC units use the most energy at startup. So if you turn the system off every time you leave for a few hours and crank it back on when you return, it’s actually working harder. Letting it maintain a consistent temperature with slight adjustments is often more efficient.
Use Your Thermostat to Your Advantage
If you’re gone during the day, raise the thermostat a few degrees — maybe to 78°F — rather than shutting the system off entirely. Then, lower it back down to your comfort level when you return. This keeps the house from getting too hot and humid while still saving energy.
Smart thermostats take this one step further by learning your habits and adjusting automatically. Many also allow you to control settings from your phone, so you can cool things down before you get home.
What About All-Day Cooling?
If you work from home or have pets, it makes sense to keep your home at a steady, livable temperature. In fact, constantly cycling on and off to catch up can wear on your system. A steady, moderate workload is usually healthier for your equipment than frequent spikes.
When Should You Turn It Off Completely?
If you’re going away for a long weekend or a vacation, it’s fine to turn the system off — or set it to something like 85°F. Just be mindful of humidity. If the home gets too damp, it can lead to musty smells or even mold growth. For long absences, consider a dehumidifier or leave the fan running occasionally.
Bottom Line
Yes, it’s usually okay to leave your AC on all day — as long as you’re adjusting the temperature when you don’t need it working as hard. For most New England homes, a well-maintained system and a smart thermostat are the best combination for comfort and efficiency.
Need help optimizing your setup? McKee Energy Services is here to help.