Is 70 too cold for AC in summer?

Author: Frances Padberg  |  Last update: Wednesday, February 4, 2026

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 70 degrees too cold for AC?

70°F is an ideal temperature setting, regardless of how hot it gets outside. This is a comfortable temperature for most, though you may find that it can feel too cold at times. Any air conditioner set lower than this is at risk of having its coil freeze.

Is 72 a good temperature for air conditioning in summer?

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.

Is 70 too low to set AC?

Most experts maintain that running your AC below 70 degrees can cause issues with your unit, including the risk of freezing the evaporator coil. It's worth noting this low setting would also quickly run up your energy bill.

How cool should my house be if it's 100 outside?

When temperatures exceed 100 degrees Fahrenheit outside, setting your air conditioning (AC) to around 75-78 degrees Fahrenheit is generally considered efficient. Here are some reasons for this recommendation:

Is 70 too cold for AC?

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

Just because the outdoor temperature is above 100, the Ideal temperature to set your AC unit to doesn't change — it's 78 degrees. Higher temperatures in the home are to be expected when the weather is hotter than usual, but your thermostat can still be set the same as if it were a lower temperature outside.

What should I set my AC to on a 100 degree day?

For the most efficient performance, set the thermostat 20 degrees lower than the temperature outside. On a 100℉ day, set it to 78℉ to 80℉ to manage utility costs. If there's a lack of airflow, the filter may need to be changed or AC vents cleaned. But it may also mean your air conditioner needs professional repair.

What is the best temperature for AC in summer?

It turns out that the best indoor temperature for your home during the summer months is 78 degrees, according to the U.S. Department of Energy. If that temperature falls outside your comfort level, there are several ways to modify how your home feels without causing your energy bill to spike.

Is 70 too high for thermostat?

Set your thermostat to 68 degrees

68 degrees Fahrenheit, according to the Department of Energy. But if that's too specific, anywhere around 70 degrees is a good target when it gets cold, Ram Narayanamurthy, deputy director of the U.S. Department of Energy's Building Technologies Office, told USA TODAY.

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.

What is the safest temperature for AC?

Hence, to take a temperature closer to 24 degrees is considered to be healthier for individuals in tropical regions like India. The ministry says that, as per the comfort chart, temperatures up to 25 degrees are quite comfortable for human body, along with the desired humidity and air movement values.

What should I set my AC thermostat in the summer?

To stay comfortable and save money, the U.S. Department of Energy recommends the best AC setting during summer is 78°F (26°C) when you are home. Setting your air conditioner to this level will allow you to stay cool and avoid an unusually high electricity bill.

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.

Is 70 Degrees too cold for a house?

Recommended Temperature When You Are Home

The World Health Organization (WHO) recommends setting your thermostat no lower than 64 degrees (F) in the Winter months while people are in the home. If there are infants or elderly individuals, they recommend keeping the temperature at 70 degrees at a minimum.

Is 69 too cold for AC in summer?

While it can be tempting to crank your thermostat down to the 60s after a long, hot day, keeping your AC at around 73-78 degrees is ideal for maintaining the efficiency of your system.

What is the lowest you should set your AC?

In short, the 20-degree rule of air conditioning states that you should always keep your AC unit at no more than 20 degrees lower than the outside temperature. It means that, if the outdoor conditions are at 95 degrees, you should set your thermostat at no less than 75 degrees.

Is 72 too high for thermostat in summer?

ASHRAE, unlike the EPA, specifies an ideal number to set a building's thermostat to. It's a range, actually: around 23°-26°C, or 73.4°-78.8°F, in the summer.

What temperature to keep a house in summer?

For summer, Direct Energy recommends that the ideal thermostat temperature should be 78 degrees Fahrenheit or 25 degree Celsius when you're at home. You should set the daytime temperature no lower than 78 degrees F (26 degrees C).

What is an unhealthy room temperature?

The World Health Organization recommends a thermostat setting no lower than 68 degrees while you're home. If you have children or seniors in your house, that number increases to at least 70 degrees. If your house is too cold, it can cause problems with blood pressure and circulation, as well as affect your heart rate.

Is 72 too cold for AC?

While the standard room temperature of 72 degrees Fahrenheit is commonly favored by many, others argue for higher settings, particularly when it's hotter outside.

What should I set my AC at during heatwave?

Rochester Electric and Gas recommends setting your thermostat at 78 degrees or higher, as each degree above 75 degrees saves 3% of energy on cooling. A higher internal temperature actually slows heat flowing into your living space, so it saves additional money on air conditioning.

What is the coolest number for AC?

Setting your AC to 16°C will cool the room more than setting it to 30°C. However, keep in mind that extremely low temperatures can lead to higher energy consumption and may not be comfortable for occupants. A moderate setting, like around 22–24°C, is often recommended for both comfort and efficiency.

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

What should my AC be set at if it's 90 degrees outside? If the outdoor temperature is 90 degrees, it's recommended to set your thermostat between 75-78 degrees.

Is 75 too cool for AC?

Most people work better and are more productive when with a temperature setting in the 72–74-degree range. This setting is low enough to keep the house cool and dry and keep you and the kids awake during the afternoon hours.

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.

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