When the summer heat hits, everyone asks the same question: What is the best temperature for air conditioning in the summer? According to the U.S. Department of Energy (DOE), the best starting point is between 75°F and 78°F when you’re home. This range offers a good balance between energy savings and indoor comfort, and it prevents your air conditioner from running nonstop in a losing battle against extreme outdoor heat.
Want to save even more? The DOE recommends raising your thermostat by 7°F when you’re not home. That means if you keep it at 76°F during the day, increasing it to 83°F while you’re out can significantly reduce your energy usage and costs without sacrificing much in the way of comfort.
At 5 Star HVAC Contractors, we’ve been helping families across our community stay cool and save money for years. As licensed professionals who treat your home like it’s our mother’s, we’re here to help you keep your home comfortable without overworking your system or draining your wallet.
How to Stay Comfortable — Even at 78°F
You don’t have to suffer through the summer just to save money. By building a few smart habits, you can stay cool even when your thermostat is set a little higher. These tips combine Department of Energy recommendations with the hands-on experience of our 5-Star technicians.
1. Use a Smart Thermostat (the Right Way)
Programmable or smart thermostats let you schedule temperature changes throughout the day, so your home stays cool when it matters most and saves energy when it doesn’t. For example, you can program your smart thermostat to raise the temperature when everyone leaves for the day and bring it back down before anyone returns.
Just make sure you’re using the right thermostat for your system. Some models don’t work well with heat pumps or multi-zone setups, which can lead to inefficiencies or comfort issues.
2. Keep Filters Clean
Dirty filters restrict airflow and make your air conditioner work harder than necessary. This not only drives up energy costs but can also shorten your system’s lifespan. During summer, it’s best to check filters monthly and replace or clean them as needed.
If you have pets or allergies, you may need to replace filters more often. A quick inspection can help you spot dust buildup or discoloration. These are both signs it’s time to change your filters.
3. Close Curtains During the Day
Sunlight streaming through windows can quickly raise indoor temperatures. Thus, closing blinds, shades, or curtains during peak sun hours (typically between 10 a.m. and 4 p.m.) helps keep your home cooler naturally. This simple step can reduce indoor heat gain by as much as 77%.
For best results, use light-colored or reflective window treatments to bounce heat away. If you’re planning to upgrade, insulated or blackout curtains offer even more protection.
4. Use Fans Smartly
Fans help air circulate, making your home feel cooler and allowing you to raise your thermostat by a few degrees without losing comfort. However, fans don’t lower the air temperature — they only cool the people in the room. So, remember to turn fans off when you leave a room to avoid wasting electricity. Ceiling fans should rotate counterclockwise in summer to push cool air downward.
5. Seal Air Leaks and Insulate
Even the best thermostat setting won’t matter much if your cool air escapes through cracks and gaps. Check around doors, windows, and attic spaces for drafts. Sealing these leaks with weatherstripping or caulk helps maintain a steady indoor temperature.
Proper insulation, especially in the attic, also plays a huge role in regulating temperature. Well-insulated homes stay cooler longer and reduce the workload on your HVAC system.
6. Use Exhaust Fans with Intention
Kitchen and bathroom exhaust fans help remove heat and humidity, but they also pull out cooled air. Limit their use to when they’re truly needed, and turn them off about 20 minutes after cooking or showering.
More Tips for Staying Cool Without Overusing AC
Staying comfortable in summer doesn’t mean relying solely on your air conditioner. These extra tips will help you stay cool, reduce your carbon footprint, and save money on utilities:
- Switch to LED lighting. Traditional bulbs generate more heat than you might expect. LEDs use less energy and keep indoor temperatures down.
- Avoid heat-producing appliances. Try grilling outside or using the microwave instead of the oven during the hottest part of the day.
- Use zoned cooling. If your system allows, cool only the rooms you’re using. Close vents in unused areas to redirect airflow.
- Upgrade to ENERGY STAR equipment. When it’s time for a new unit, choose a model that meets or exceeds federal energy efficiency standards. It’ll save money long-term and improve performance.
By adopting a whole-home cooling approach, you can take pressure off your AC and enjoy a more balanced, comfortable environment.
Summer AC Temperature FAQ
Can I Set My Thermostat to 72°F or Lower?
Yes, you can set your thermostat to 72°F in the summer, but it will cost you more. The U.S. Department of Energy states that each degree below 78°F can increase your cooling bill by about 3%. While 72°F might feel more comfortable for some, it significantly increases energy consumption and utility costs.
Unless someone in your home has specific health or comfort needs, sticking to 75°F-78°F is a more energy-efficient choice. Lower settings won’t cool your home faster either. AC units cool at a constant rate regardless of the setting.
What Temperature Should I Set My AC to If I Have Pets?
Most household pets, like dogs and cats, can remain comfortable in indoor temperatures between 75°F and 80°F. The key is to ensure they have access to water, shaded areas, and good air circulation.
If you’re raising the thermostat when leaving home, consider your pet’s age, breed, and health. Short-nosed dogs (like bulldogs), elderly pets, or animals with medical issues may require a slightly cooler environment—around 76°F to 78°F is a safer range in those cases.
What Temperature Should I Set My AC to During a Heatwave?
Even during a heatwave, the ideal indoor temperature remains around 78°F. Most AC systems are designed to cool indoor air up to 20°F below the outside temperature. So if it’s 100°F outside, your system is already working hard to maintain 78°F inside.
Instead of lowering the thermostat dramatically, use layered cooling methods. Keep curtains closed, run ceiling fans, avoid using ovens or dryers during peak heat hours, and stay hydrated. If your system struggles to maintain 78°F, it may be time for a tune-up.
Comfort, Savings, and 5-Star Service — All Summer Long
There’s no one-size-fits-all answer to the perfect summer AC setting. But with expert-backed recommendations, a few smart strategies, and support from HVAC pros who put your comfort first, you can enjoy cool air without high energy bills.
At 5 Star HVAC Contractors, we’re here to help, whether you need a tune-up, a thermostat upgrade, or just honest advice on what temperature to set your air conditioner in the summer.
Ready to get your system summer-ready? Contact 5 Star HVAC Contractors today to learn how our air conditioning services can keep you safe and comfortable while lowering your energy bills.
