Finding the right thermostat setting can mean the difference between high utility bills and a comfortable home. Knowing what temperature you should keep your air conditioner on helps you stay cool, save money, and extend the life of your AC unit. This detailed guide explores recommended temperature settings, energy-saving strategies, considerations for families, and answers the most common questions Americans have about summer cooling.
| Recommended Thermostat Setting | Conditions | Potential Benefits |
|---|---|---|
| 78°F (26°C) | When home and active | Energy savings, comfort balance |
| 82-85°F (28-29°C) | Sleeping, away from home | Maximum savings, reduces AC load |
| 70-76°F (21-24°C) | Special needs (elderly, illness) | Enhanced comfort and health safety |
The Ideal AC Temperature For American Homes
According to the U.S. Department of Energy and the Environmental Protection Agency, the recommended air conditioner setting is 78°F (26°C) during the summer when you are at home and awake. This temperature offers a sweet spot between comfort and energy efficiency for most American families.
When you’re away from home or asleep, experts suggest raising the thermostat by 7-10 degrees higher. This strategy helps reduce cooling costs by up to 10% a year, according to Energy Star.
Why 78°F? The Science Behind The Recommendation
Setting your AC at 78°F helps align indoor comfort with outdoor heat without overburdening your cooling system. For many adults in light clothing, this temperature feels comfortable with sufficient air circulation, especially when humidity is controlled.
Each degree below 78°F can increase energy costs by 3-8%. Maintaining 78°F as the default avoids excessive energy use and supports environmental sustainability while maintaining reasonable comfort.
AC Temperature Settings For Sleep
For restful sleep, most people prefer a room between 60°F to 67°F (16°C to 19°C). However, if maximizing savings is a goal, 82-85°F is an acceptable range for unoccupied homes or nights when using fans and light bedding.
If you wake up feeling too warm, consider using ceiling or stand-alone fans in tandem with your air conditioner. Running your AC lower than 78°F at night can cause significant increases in energy consumption and costs.
Energy Savings From Higher AC Settings
For every degree you raise your thermostat above 72°F, you can save 3-5% on cooling costs. Over the course of a warm season, these savings become substantial, especially in states with lengthy heat waves.
- At 78°F: Balance between efficiency and comfort
- At 80°F+: Best for brief periods when away
- At 72°F or lower: Instant cooling, but much higher energy bills
Factors That Influence The Best AC Setting
Several elements impact the optimal temperature for different households:
- Humidity: High indoor humidity makes rooms feel warmer; set lower if humidity is not well controlled.
- Home Insulation: Better insulation allows higher temp settings without discomfort.
- Sun Exposure: South- and west-facing rooms heat up more quickly; they may need cooler settings.
- Number Of Occupants: More people generate more heat, potentially requiring lower settings.
- Health Needs: Babies, elderly, and those with medical conditions often require cooler temps.
- Pets: Dogs and cats tolerate warmer temps, but pets with thick coats or health issues may need it cooler.
Programmable & Smart Thermostats
Investing in a programmable or smart thermostat enables automatic temperature adjustment throughout the day, maximizing comfort and savings. Features include:
- Set schedules (home, away, sleep)
- Remote access via phone apps
- Learning preferences over time (smart models like Nest or Ecobee)
- Compatibility with home automation
Using a smart thermostat with Energy Star certification can further reduce annual cooling costs by 10% or more.
What If 78°F Feels Too Warm?
Not everyone enjoys 78°F. For extra comfort without turning down the thermostat, consider these tips:
- Use Ceiling Fans: Wind chill effect can make it feel up to 4°F cooler.
- Close Shades Or Curtains: Reduces solar heat gain, especially in the afternoon.
- Seal Air Leaks: Prevents warm air intrusion that can make 78°F feel hotter.
- Avoid Ovens & Stoves: Use microwave or grill on hot days.
- Install Dehumidifiers: Lowering humidity makes the air feel cooler.
By combining these strategies, most residents find 78°F far more tolerable and often avoid the urge to decrease the temperature setting.
Special Considerations For Elderly And Young Children
Elderly individuals and infants are more vulnerable to heat stress. For households with these members, experts recommend setting air conditioners between 70°F to 76°F, especially if outside temperatures exceed 90°F for multiple days. Watch for symptoms of overheating, including fatigue, red skin, or dizziness.
If you must compromise, keep vulnerable family members in one well-cooled room while other parts of the home remain at 78°F or higher. A portable AC or fan may help if lowering the thermostat for your whole home is not economical.
Best AC Settings When Away From Home
Raise the temperature to 82-85°F when you’re away for a few hours or more. This limits excessive AC cycling and utility use. However, avoid turning the AC off completely; it can increase humidity and potential mold growth, especially in humid regions.
Use the “hold” or “away” setting on your programmable thermostat, or manually adjust before leaving home. Upon return, restore to your preferred cooling setting about 30 minutes before you’ll need it.
Should You Turn Off The AC Entirely?
In most climates, it is not recommended to turn off your air conditioner completely in hot weather. A completely off system allows indoor temperatures to rise excessively, making it harder and more expensive to cool down when you return. Additionally, high humidity can foster mold growth and damage wooden fixtures.
Instead, raise the thermostat to the highest comfortable setting and close blinds, doors, and vents in unused rooms.
Tips For Saving On Air Conditioning Bills
- Keep Thermostat At 78°F: Primary way to save without sacrificing comfort.
- Use Fans: They boost the cooling effect but draw much less power than an air conditioner.
- Service AC Regularly: A well-maintained AC runs more efficiently.
- Seal Ducts: Leaky ducts can waste up to 30% of cooling energy.
- Upgrade Windows: Insulated windows reduce heat gain dramatically.
- Cook Smart: Use the grill or microwave to avoid heating the home with your stove or oven.
- Install Solar Screens: Reduce solar gain on sunny sides of your house.
Cost Comparison: AC Settings And Potential Savings
| Setting | Potential Cooling Cost (Monthly) | Estimated Energy Savings |
|---|---|---|
| 72°F | $180 – $250 | 0% baseline |
| 74°F | $165 – $220 | 6% |
| 76°F | $150 – $200 | 12% |
| 78°F | $135 – $180 | 18% |
| 80°F | $125 – $160 | 22% |
Numbers are averages for a typical American home in a warm climate and may vary based on region and energy rates.
Should You Adjust The Temperature For Different Rooms?
Many modern homes have zoned AC systems that allow different temperature settings for bedrooms, living rooms, or basements. Setting warmer temps in unused spaces and cooling occupied rooms can lead to further savings.
For single-zone systems, blocking or sealing vents to unused rooms may help. However, never close off more than 10% of vents, as it can disrupt air balance and strain your system.
Humidity: The Hidden Comfort Factor
Humidity heavily influences comfort at a given temperature. High indoor humidity makes 78°F feel much warmer. Keep relative humidity below 50% by using your AC’s “dry mode,” ensuring proper drainage, and running a dehumidifier if needed.
Lower humidity may allow for a higher AC setting without loss of comfort. Dry air feels cooler, letting you save by running your unit less often.
Window Units Vs Central Air: Are Temperature Settings Different?
The ideal setting remains the same—78°F (26°C) is recommended for both types. However, room (window) ACs are most efficient when cooling only what is needed. Shut doors and windows to isolate rooms and avoid unnecessary cooling.
Central air is best used with programmable thermostats and whole-home strategies, such as closing blinds and sealing leaks.
State-By-State: Do Climate Zones Impact The Best AC Temperature?
Climate has a significant effect on optimal settings. In the South and Southwest, robust AC is non-negotiable, while in the North, comfort can sometimes be maintained at 80°F or above with fans.
- South/Southwest: 74-78°F is most common, with AC used nearly continuously in summer.
- Midwest/North: 78-80°F is feasible; open windows and fans can maintain comfort.
- Coastal: 76-80°F, with AC less frequently necessary.
Regardless of state, starting at 78°F and adjusting based on comfort, humidity, and specific health needs delivers the best balance for American homes.
Frequently Asked Questions About AC Temperatures
| Question | Answer |
|---|---|
| Is 78°F too hot for AC? | 78°F suits most adults; increase fans or reduce humidity if it feels warm. |
| Does turning AC lower cool the room faster? | No. ACs cool at the same rate regardless of setting; setting lower wastes energy. |
| How often should I change temperature settings? | Stick to a consistent schedule, adjusting only for sleep, absence, or unusual heat. |
| Is it harmful to set AC very low? | Yes. Settings below 70°F can freeze coils, increase costs, and reduce unit lifespan. |
| Should I leave the AC fan on “Auto” or “On”? | “Auto” saves energy; “On” improves air filtration but uses more electricity. |
Final Thoughts On Air Conditioner Temperature Settings
Setting your thermostat at 78°F is the expert-recommended balance of comfort and cost for American households. Adjust as needed for health, humidity, or special preferences, but avoid lowering below 72°F unless medically required. Leverage fans, insulation, and smart thermostats to get the best results—and enjoy a cool, efficient summer indoors.