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when to turn on ac

When To Turn On Your Air Conditioner? Myths Busted!

In the hot summer months, an air conditioner is a must-have. But, as summer approaches, when is the best time to turn on your air conditioner?

In general, you can turn on your ac when the indoor temperature is above 75 degrees. However, the insulation, indoor humidity, your preference, and many other factors will have an impact.

I will go over each factor that will affect your decision so that you can figure out the best time to turn on the AC for your comfort and money.

At what temperature should you turn on the AC?

According to the World Health Organization, keeping indoor temperatures between 64 and 75 degrees Fahrenheit is good for healthy people. But for the very young, the elderly, or people with health problems, 68 degrees Fahrenheit is the minimum temperature to maintain.

In addition to that, the lower the temperature you start to use the AC, the more energy bill you have to pay.

As a result, turning on your AC when the indoor temperature is above 75 degrees is a sensible idea for most of us. It can not only ensure your comfort but also save money.

Best time to turn on your AC to save money

best time to turn on ac

There are other tips on when to turn on your ac to save money besides turning it on at 75 degrees.

Turn it on in the morning

If you are turning on your air conditioning system for the first time this year, turning it on in the morning will save you money.

This is because morning is usually the coolest time of day because the temperature drops overnight. As a result, your air conditioner does not have to work as hard to cool the room, saving you money on energy.

Use a programmable thermostat

As technology advances, you no longer have to decide the best time to turn on your AC.

By implementing a smart thermostat, it will control your indoor temperature automatically. You can set the temperature a bit higher when you are outside the home and a bit lower when you are back. 

This way, the temperature in your house will be stable, saving energy and ensuring you can enjoy a comfortable temperature at home.

Other factors that affect the time to turn on the air conditioner

Many people are used to checking the temperature on weather APPs. However, the outdoor temperature is correlated but different from the indoor temperature.

Even though I have said that turning on the AC when the temperature arrives at 75 degrees is good, it doesn’t mean that it is the best solution for you. Many factors can have an impact on your decision.


You may postpone the time to run your AC if your house has high-quality insulation. The insulation can assist in keeping the hot air out so that you often feel the house is a few degrees colder than the outdoors.

As long as you don’t feel uncomfortable, it is OK to keep your AC off even if the outside temperature is over 75 degrees.


Aside from temperature, humidity is an important factor in maintaining a comfortable level. When a room is overly humid, you will feel hotter than usual because the sweet evaporation is hampered, resulting in more heat in your body.

As a result, those who live in humid areas should expect to run their air conditioner at a lower temperature, such as 70 degrees. ACs can dehumidify the air while also cooling it, which is good for your health.

Do you have other means to cool your room?

ceiling fan

The air conditioner is not the only means to make you feel cool. For instance, running a dehumidifier can make you feel cooler by promoting the evaporation process.

Beyond that, a fan can create airflow and take away your sweat, which can lower your body temperature. 

Even though these devices are not able to cool your room exactly, but can make your feel better.

If you have these devices running, you may not require to turn on your AC.

Your personal preference

Believe it or not, the ideal room temperature for each individual varies. Some people enjoy the cold, while others prefer to be in a warm environment.

As a result, the time you run your air conditioner is also determined by your preferences. However, forcing yourself to endure hot weather is not a good idea because it may increase your healthcare costs.

Considerations before turning on your AC

Once you confirm the best time to run your AC, you should exercise caution before turning it on.

Allow some time to settle

When you have a new device, it is recommended to wait up to 24 hours before turning it on. This also applies to AC that is stored on the side. This is because the oil in the compressor needs some time to settle back to the bottom.

However, not every air conditioner requires time to settle. If you don’t move it for a long time, you can start running it immediately. 


It is preferable to have your air conditioner serviced in the spring before turning it on. This ensures that your machine works efficiently and consumes less energy. Regular maintenance can also help to extend its life.


If you’re not sure when to turn on your air conditioner, this post will help. Simply put, when the indoor temperature rises above 75 degrees, you should turn on your air conditioner.

However, if the air is too humid, you may need to turn it on earlier or delay it if you have ceiling fans in your home.

Running your air conditioner when the temperature is below 64 degrees can be hazardous to your health.

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested more than 150 products in person, including humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.

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