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Air Conditioners, HVAC Education

What is the Best Temperature for AC?

By Travis Baugh

It happens every year. Outdoor temperatures start heating up, you turn on your central air conditioning, and now it’s decision time: What temperature should I set my air conditioner in summer? According to the Department of Energy1, 78° Fahrenheit is the sweet spot for air conditioners to balance energy savings and comfort when people are at home and need cooling. But in reality, this is a question that doesn’t have a “one size fits all” answer.

A Carrier technician setting the best temperature for ac on an air conditioners thermostat.

Determining the right answer for you will require some experimentation with different settings. It will also require determining whether you are more interested in achieving lower electricity bills, higher comfort levels or a balance of both. Other factors that can affect the best temperature for AC in your home include the number of people, amount of physical activity, and exterior factors like humidity, amount of direct sunlight, number of windows, and more. Ultimately, the best AC setting for your home is the one that makes you and your family comfortable with utility costs you can afford.


Conserving energy with your air conditioner can be achieved through a few simple steps. Firstly, during the summer months, setting your thermostat a few degrees higher than your normal setting can help conserve energy. Secondly, when you're away from home, it's advisable to set your thermostat at a higher temperature to reduce unnecessary cooling. This ensures your air conditioner doesn't work as hard and can help save energy. Lastly, performing regular preventative annual maintenance can help ensure your system operates efficiently. In addition, there are several other tips that can help conserve energy even without relying heavily on your air conditioner, and we will explore those in more detail below which we’ll discuss later.
A Carrier dealer explaining to a couple the best ac temperature for sleeping


When the heat and humidity have you working up a sweat, the temptation is to crank up the AC and enjoy that nice, cool, dry air. Then you get your utility bill and it hits you... there’s a price to pay for all of that extra comfort. You want to save money, so you set your thermostat several degrees higher and the cycle starts all over again. If this sounds all too familiar, there are some ways to find that comfortable balance between comfort and savings.

Start by setting your thermostat higher than normal when you are away, and at 78 degrees when you are home. That is the Department of Energy’s recommended setting when you need cooling, but want to save energy. If you find that your home is too hot for comfort, try reducing the temperature setting by a degree or two to see if you feel cooler. Continue to reduce your temperature setting by one or two degrees until everybody is consistently comfortable. As you experiment with finding the setting that works for you, consider using some of the energy-saving and comfort-enhancing tips that follow.

A carrier dealer showing a woman what temperature should I set my air conditioner in summer.

Set the Thermostat at a Higher Temperature When You’re Gone

One simple way to decrease energy costs is having a higher temperature setting on the thermostat when nobody is home. While you might be tempted to simply turn the AC off, it’s actually better to adjust the temperature several degrees higher, by about 7-10 degrees. By installing a programmable thermostat and making this simple adjustment you can potentially save as much as 10% on your energy bill.1 Completely shutting down the system might actually cost you money due to the extra energy it takes to cool your home back down to your comfort zone.

Another habit to avoid when looking for the best temperature for AC settings is setting the thermostat on a colder setting to cool the home down more quickly after you’ve been away. Your air conditioner will not cool any faster – it will cool at the same rate, but will run longer until it reaches the lower temperature. In the long run, that extra cooling can actually result in an unnecessary expense. If you don’t already have one, a better solution is to use a programmable thermostat or even a smart thermostat. These thermostats can be set to automatically raise the temperature when you are away and re-set the system for a more comfortable temperature by the time you return. With a smart thermostat, you can adjust the settings wherever you are, using a connected device like a smart phone or tablet.

Cooling Your Home Without AC

Some simple tricks for potentially saving money might be right there in front of you. If you have ceiling fans installed in your home, use them! Increasing airflow in a warm room won’t reduce the temperature, but it will help to make it feel cooler and more comfortable. And, running a small fan takes less energy than running the air conditioner. If you don’t have ceiling fans, a standalone fan can have the same effect. Available in a variety of sizes and styles, from a small desktop fan to a larger box fan that sits on the floor or even a narrow-profile tower fan, you can find one that fits your budget and can be moved from room to room as needed.

Additional comfort-enhancing (and money saving) suggestions include:

  • Closing window coverings during the day to reduce heat from sunlight.
  • Turn off your AC and open windows at night to naturally cool your home. Shut the windows during the day to seal in the cooler air.
  • Add weather stripping to window and door openings to better seal in comfort and seal out heat.
  • Avoid using heat-generating appliances such as an oven, your clothes dryer, hair dryers, etc., especially during the day.

Perform Regular Maintenance on Your Air Conditioner

Even ENERGY STAR® certified air conditioners need some regular TLC to deliver their expected efficiency ratings. Because much like your car, your central air conditioner operates more efficiently with routine maintenance and system check-ups. For example, a dirty, clogged air filter can restrict air circulation, potentially causing loss of comfort and reduced energy efficiency, while also putting a strain on the system’s fans and motors. As a part of standard AC Maintenance, most homeowners can handle checking, cleaning or replacing the air filter. However, experienced HVAC professionals have the training and the equipment to dig deeper. They can assess system performance, clean and adjust internal components and take care of any minor issues before they become big problems. A professional air conditioner tune-up can help maintain the efficiency of your system with services like:

  • Cleaning the outdoor coil: A dirty outdoor coil affects system performance by restricting airflow and heat transfer needed for proper cooling operation.
  • Cleaning the evaporator coil: A dirty evaporator coil affects system performance by restricting airflow and heat transfer needed for proper cooling operation, and can affect indoor air quality with build-up of mold and bacteria.
  • Checking refrigerant levels: Low refrigerant levels can reduce cooling capability, causing the system to run longer and use more energy trying to maintain comfort.
  • Cleaning and adjusting blower components: Your indoor blower circulates indoor air through the system and returns cool air back to your home. A poorly functioning blower can affect both comfort and energy costs.
  • Installing a smart thermostat: As mentioned previously, installing a smart thermostat can help you more effectively manage your temperature settings. Consider having your dealer install one during one of their regular scheduled tune-up visits.

What is the Best AC Temperature for Sleeping?

Although 78⁰ F is a good temperature for energy savings and comfort when you are home and awake, it is not ideal for slumber. In fact, bedroom temperatures that are too hot or too cold can make it hard to fall asleep which could result in a restless night and low-quality sleep. A general recommendation is that the optimal temperature for sleeping is between 60⁰ and 67⁰ F, regardless of the season outside.3

  • To help ensure a better night’s rest, consider re-setting your thermostat before you go to bed, leaving enough time for the temperature in your bedroom to adjust.
  • If you have a programmable thermostat, you may want to schedule it to automatically reduce the temperature during the times you are normally asleep.
  • If it works for you and your climate, try opening a few windows. This method will depend upon having milder, cooler outdoor temperatures, and offers a more energy-efficient, but less precise, option for achieving the targeted 60⁰ - 67⁰ F. Be sure to close the windows in the morning to seal in the cooler air.

The above recommendations are for a typical adult. Keep in mind that infants and small children should be in rooms with a slightly higher temperature to ensure better, more restful sleep.


You can determine if an AC thermostat is malfunctioning by understanding how thermostats work: they should reliably control and maintain your desired temperature. If the thermostat fails to start the AC, does not maintain set temperatures, or behaves erratically, it may be faulty.
According to the Cleveland Clinic, the recommended thermostat setting for nighttime is between 60°F and 67°F.3 Setting your AC within this range can help maintain a comfortable sleeping environment.
Setting your air conditioning to 72°F is generally considered a comfortable indoor temperature for many people. It strikes a good balance between comfort and energy efficiency, making it a popular choice for residential settings.
Setting your AC to 68°F might feel too cold for some, especially in residential settings, as it is lower than the typical comfort range. However, preferences vary, and this temperature might be suitable for those who prefer cooler environments.
In summer, the best mode for your air conditioner is the "Cool" mode, set to a comfortable temperature around 78°F when you’re home. This setting efficiently reduces indoor humidity and maintains a comfortable environment without overworking the AC system.
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