What's The Best Temperature Setting For AC?

set ac temperature with smart thermostat

Having the right temperature setting for AC in the summer is a subject of debate among homeowners, experts, and energy conservationists. It involves various factors, including personal preferences, environmental conditions, and energy efficiency.

The Department of Energy recommends 78°F as the ideal temperature for AC, but there are different strategies and techniques that you can use to find the best temperature setting for your home.

In this article, our HVAC technicians draw upon their decades of experience to explore the factors that influence the optimal temperature setting for AC, the relationship between energy efficiency and AC temperature, and different scenarios where specific temperature settings may be appropriate. Additionally, we will examine the advantages of programmable and smart thermostats in helping you find the ideal temperature setting for your needs and debunk some common misconceptions about AC temperature settings.

Finally, we will provide tips on enhancing comfort and efficiency beyond AC settings to help you save money on utility bills while keeping your home cool and comfortable.

Key Takeaways

  • The Department of Energy recommends 78°F as the sweet spot for AC temperature, but the best setting for a home depends on personal preference and factors like humidity, sunlight, and physical activity.
  • Experimentation with different settings is necessary to determine the right AC temperature for a home, and setting the thermostat higher when away can save up to 10% on energy bills.
  • Using ceiling fans or standalone fans can increase airflow and make a room feel cooler, and closing window coverings during the day and opening windows at night can naturally cool a home.
  • Quality of sleep may be improved with lower temperatures.
  • Regular maintenance of the AC system, including cleaning and replacement of filters, can improve efficiency and reduce energy costs.
  • Regular preventative maintenance can help reduce the risk of needing AC repairs in the middle of a hot Texas summer.
  • Proper sizing of an AC system is important for efficiency and comfort.

Factors Influencing Optimal AC Temperature

When determining the optimal temperature setting, it's important to consider various factors that influence your comfort preferences. While the Department of Energy recommends 78°F as the sweet spot, the best AC setting for a home really depends on your personal preference and factors like humidity, sunlight, and physical activity.

  1. Local Climate: The outside temperature and humidity levels can greatly affect what temperature you should set your air conditioner at. This includes seasonal variations and sudden changes in weather.
  2. House Size and Insulation: Larger homes or homes with poor insulation may need cooler settings to achieve the same level of comfort. Proper insulation can help maintain temperature and reduce the work load on your AC.
  3. Number of Occupants: More people in the house can generate more heat, which might require a lower temperature setting.
  4. Personal Comfort Preferences: Everyone has their own idea of what temperature is comfortable. Some people may prefer a warmer home, while others may want it to be cooler.
  5. Time of Day: During the nighttime, when outside temperatures drop, you may not need to set your AC as cool. Although some people like to sleep with the air turned down cold. Sleep experts often recommend a cooler setting at night which helps the body lower its core temperature, and thus a better quality of sleep.
  6. If House is Empty or Occupied: When the house is empty, you can typically set the AC at a higher temperature to save energy.
  7. Health Conditions: Certain health conditions may require a home to be at a specific temperature. For instance, some people with respiratory issues may require a cooler home.
  8. Age of Occupants: Elderly people and infants often have different temperature needs and may require a different setting.
  9. Type and Age of Your AC: Older air conditioners might not be as efficient, which could affect the optimal temperature setting. The type of AC (window unit, central AC, etc.) can also impact the best temperature settings.
  10. The 20-Degree Rule: As a general rule, your AC should not be set more than 20 degrees cooler than the outside temperature for optimal performance and efficiency.
  11. Humidity : Humidity control is also an important consideration; high humidity levels make a room feel warmer, whereas low humidity makes it feel colder. During hot and humid months, setting the AC temperature lower may be necessary to control humidity levels and maintain a comfortable indoor environment.

Energy Efficiency and AC Temperature

A common misconception is that setting the AC temperature really low will cool a room faster, but this is not true. In fact, it can lead to increased energy consumption and higher utility bills. In most cases, your home will never cool down to an extremely low setting due to various limiting factors we'll talk about later.

The Department of Energy recommends setting the daytime AC temperature to 78°F for maximum energy savings. When no one is home, or at night, the temperature can be raised by 7°F to save even more on energy costs.

While it may be tempting to set the AC temperature to the lowest possible setting, this can lead to energy waste and higher costs. Instead, homeowners can use smart or programmable thermostats to automatically adjust the temperature based on their schedule and preferences, finding a balance between comfort and energy efficiency.

Optimal Temperature Settings for Different Scenarios

To achieve maximum energy efficiency and comfort, consider the optimal temperature for different scenarios.

  • For sleeping, the recommended temperature range is between 65 and 70 degrees. However, infants and small children may require slightly higher room temperatures for better sleep. It is also important to take into consideration home insulation, climate control, and outside air temperature when setting the thermostat for sleeping.
  • When away from home, setting the thermostat higher can save up to 10% on energy bills. The U.S. Department of Energy recommends finding a comfortable temperature when at home and awake, then increasing the temperature by 4°F when asleep and 7°F when no one is home.
  • Programmable thermostats can help match cooling needs to schedules and can automatically adjust the temperature for comfort and energy savings. Experimenting with different thermostat settings and taking advantage of natural cooling strategies, such as using ceiling fans and opening windows at night, can also help determine the best AC temperature for a home.

Programmable and Smart Thermostats

Programmable and smart thermostats offer a range of benefits for indoor comfort, energy saving tips, and smart home HVAC. These thermostats allow users to set and keep temperatures that work with their schedules, providing a comfortable environment while also helping to save energy and reduce utility bills.

With programmable thermostats, users can set different temperature schedules for different times of the day or week, while smart thermostats offer automation, remote access, and remote monitoring.

In addition to offering increased convenience and energy efficiency, programmable and smart thermostats can also help reduce the chances of needing a repair. When properly installed and maintained, these thermostats can improve the efficiency and lifespan of HVAC systems. However, it is important to choose a thermostat that is compatible with your HVAC system and to follow manufacturer instructions for installation and use.

Overall, programmable and smart thermostats are a valuable tool for managing indoor temperature and improving energy efficiency in the home.

Common Misconceptions About AC Temperature Settings

Misunderstandings about the ideal temperature for air conditioning in a home can lead to discomfort and higher energy bills. To avoid these issues, it is important to address common misconceptions we hear a lot.

  • Setting the temperature lower than desired will not cool a home faster. The AC system will only work to reach the desired indoor air temperature, regardless of how low the thermostat is set.
  • Every degree you lower your AC increases your energy consumption, and conversely, every degree you raise the temperature can result in energy savings. The estimate often quoted is that you can save up to 1-3% on your cooling expenses for each degree you raise the thermostat. For example, if the indoor air temperature is already too high, raising the temperature by only one degree may not provide significant energy savings. this rule doesn't apply in every situation. If your indoor temperature is already high and uncomfortable, raising the temperature won't necessarily result in significant energy savings, because the comfort of the home's occupants is also important. The idea is to strike a balance between energy efficiency and comfort.
  • The ideal unoccupied home temperature is not a one-size-fits-all solution. The recommended temperature for an unoccupied home varies depending on factors like climate and insulation. It is important to experiment with different settings to find the most energy-efficient solution for your home.
  • Energy-efficient AC systems may not always provide the most comfortable indoor air temperature. While high-efficiency AC systems can reduce energy costs, they may not be suitable for homes in extremely hot climates or with poor insulation.

By understanding these common misconceptions, homeowners can make informed decisions about their AC temperature settings and improve their comfort and energy savings.

Tips to Enhance Comfort and Efficiency Beyond AC Settings

While the temperature setting is crucial for comfortable indoor living, there are other factors to consider beyond the AC settings.

  • Zoning systems can help regulate temperatures in different areas of the home, allowing for more customized comfort and potentially reducing energy costs.
  • Window treatments can help block out sunlight and heat, reducing the need for constant AC usage.
  • Maintaining indoor air quality is also important for overall comfort and health.
  • Regular air filter replacement and cleaning can improve the efficiency of the AC system and prevent the buildup of pollutants in the air.
  • Investing in energy-efficient AC systems can lead to long-term savings on energy bills while also providing comfortable indoor temperatures.

By considering these additional factors beyond the temperature setting, homeowners can enhance their indoor living experience while also promoting energy efficiency and cost savings.


In conclusion, finding the ideal temperature setting for your AC might seem like a complex task that depends on various factors, including personal preferences, environmental conditions, and energy efficiency goals. While the Department of Energy recommends 78°F as the optimal temperature for AC, experimentation with different settings is necessary to determine what works best for your home.

Moreover, implementing energy-saving techniques and using smart or programmable thermostats can help you save money on utility bills while keeping your home comfortable and cool.

Bear in mind that many factors can influence the optimal temperature setting for your AC. From the size and insulation of your home to the number of occupants and even the time of day, all these variables can impact the ideal temperature. Striking a balance between these factors can ensure you maintain a comfortable home environment while saving energy and keeping your AC system in good health.

But remember, even the most meticulously maintained and optimally run AC systems can encounter issues. If you find your air conditioner isn't performing optimally, is making unusual noises, or stops working altogether, it's time to call in the professionals.

At Dallas Heating and Air Conditioning, we're committed to ensuring your home is a haven of comfort, irrespective of the weather outside. Our team of certified and experienced professionals is always ready to help you with regular servicing, emergency repairs, or even advice on temperature settings.

Don't let a malfunctioning AC disrupt your comfort. Give Dallas Heating and Air Conditioning a call today and experience the peace of mind that comes with knowing your home’s comfort is in expert hands.

If you enjoyed this article, check out these other articles about air conditioning repair:
Avoid AC Breakdowns: Homeowners' Guide To Summer Preparedness
Smart Thermostats Vs Regular And Programmable Thermostats