What temperature to turn on AC?

Author: Nathen Parisian  |  Last update: Sunday, June 8, 2025

When it comes to maintaining a comfortable indoor climate while saving on energy costs, it's crucial to understand the minimum temperature for running your air conditioner. The lowest outside temperature at which to run your AC is typically around 60-65 degrees Fahrenheit.

Is 72 a good temperature for air conditioning?

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.

At what temperature should you turn the AC on?

So when can you turn on your air conditioning? A standard system that has the proper refrigerant charge and correct airflow (from good ductwork and a proper fan speed setting on the indoor furnace or air handler) can be turned on at outdoor temperatures at or above 65 degrees.

Is 68 degrees too cold for AC?

An AC unit is happiest creating space temperatures no lower than 68 degrees fahrenheit.

Is 78 too hot for a house?

Quick answer: The ideal house temperature is room temperature, which ranges from 68 to 78 degrees F, though this may vary from season to season. In winter, the average room temperature is generally 62 to 68 degrees, whereas in the summer, the average temperature is 72 to 78 degrees.

Best AC Setting For Cooling: Best Air Conditioner Temperature to Save Money, Set AC to Auto or On?

Does keeping the AC at 78 save money?

U.S. Department of Energy research suggests that setting your programmable thermostat to 78 during the summer months is the best way to save money on your cooling costs while maintaining a comfortable temperature.

What should I set my AC to in summer?

What is the Best Thermostat Setting for Summer Air Conditioner Use? Energy Star recommends the following thermostat temperatures for your air conditioner in the summer: 78°F during the day if people are home. 82°F at night if people are home.

What should I set my AC to at night?

Recommended AC Temperature for Sleeping

The Sleep Foundation says 65° is the best temperature for sleeping. However, if you prefer a slightly warmer or cooler room, that's okay, too. The recommended range is 60–68°, so there is some wiggle room.

Why is my AC set to 70 but reads 80?

Clean the Thermostat

Sometimes, when the room temperature doesn't match the thermostat setting, the problem could be dirt buildup on its interior parts. A dirt coating around the inner components may create excess heat and cause the thermostat to give the wrong readings.

What is the best mode for AC in summer?

Cool mode: Ideal for hot days, this mode reduces the room temperature to your desired setting. Dry mode: Perfect for humid conditions, this mode removes excess moisture from the air without significantly reducing the temperature.

What is the ideal temperature to run an AC?

The ideal temperature for your AC depends on several factors. In general, it's recommended to keep your thermostat between 24°C (75°F) and 26°C (78°F) for a good balance between comfort and energy efficiency. Setting your AC lower won't cool the room much more but will make it run harder and cost you more money.

What is the best temperature for sleep?

The best room temperature for sleep is approximately 65 degrees Fahrenheit (18.3 degrees Celsius). This may vary by a few degrees from person to person, but most doctors recommend keeping the thermostat set between 65 to 68 degrees Fahrenheit (15.6 to 20 degrees Celsius) for the most comfortable sleep.

How cool should my house be if it's 110 outside?

For many of us, 70 degrees is the ideal indoor temperature, but when it is close to 100 degrees outside, your AC unit will be working quite hard to meet these expectations. Consider setting your thermostat at 75 degrees to 80 degrees in your home if the outside temperature is approaching triple digits.

Why not set the thermostat at 72?

Setting the thermostat below 72 degrees while using an air conditioner can cause the unit to work harder than necessary, leading to higher energy bills and potential damage to the appliance.

Should AC be on auto or on?

There are benefits to having your air conditioner set to “auto” and “on.” The benefits of the “auto” setting include higher efficiency, lower energy bills, better humidity control, less wear and tear on some components, and quieter running.

What AC temp is too low?

A common rule of thumb is that most models can function properly only above 68 degrees Fahrenheit. Any lower temperature will result in the system freezing up. In addition to a frosty refrigerant, the piping and coils could also become covered with ice.

How cool should my house be if it's 90 outside?

If it's 90 degrees outside, most people would set their AC to a perfectly comfortable temperature of 68-72°F.

Is it OK to run AC at 70?

If you want to feel good, as in comfortable, many people will want to lower their thermostat to the low 70s in summer. But if you're talking about saving money on energy and limiting your environmental impact, 70 degrees Fahrenheit is a very bad temperature for your AC to reach.

Is 73 too low for AC?

To maintain a comfortable indoor environment during the summer, the American Society of Heating, Refrigerating & Air Conditioning Engineers recommends a range of 73 to 79 degrees Fahrenheit. On scorching hot days, you may want to adjust your thermostat toward the higher end of that range.

Does keeping the AC at 72 save money?

Best AC Temperature Settings While You Are Home

As you consider the most comfortable room temperature for your lifestyle and family, keep in mind that for each degree that you set your thermostat above 72 degrees, you can save up to 3% on your energy bill.

Is it OK to run AC all night?

Running the “auto” function of your air conditioner all day and night isn't the best idea for any home. There are a few reasons you don't want to run your AC system all the time: System stress: Your air conditioner unit needs time to take a break.

Is 72 a good temperature for air conditioning at night?

The National Sleep Foundation says 60-67 is a good temperature for sleep, but that might be too cold for you and increase your cooling bill. As a compromise, 70-plus degrees is a good setting.

Is it OK for AC to run constantly in summer?

Here's the thing: It's normal for your AC to run continuously during hot summer months. You see, on extremely hot days—we're talkin' high 90s to 100s—your system needs to keep up with the incoming heat. To do that, it will run longer in order to maintain a constant, desired temperature in your home.

What temperature do most people set their AC at?

The average air conditioning temperature depends on a variety of factors, including geographic location, comfort levels, season, and cost of energy. Anywhere between 72° to 78°F is typically standard. A study in Texas revealed that the model temperature during summer months was between 70° and 75°F.

What is the cheapest temperature to keep your house in summer?

You want to be comfortable, but also use an efficient temperature that doesn't potentially increase your energy costs. The best thermostat setting for summer is 78 degrees Fahrenheit when you're at home. Energy.gov also suggests raising your thermostat or turning it off entirely when you are away in the summer.

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