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 temperature of 72°F (22°C) is generally considered a comfortable setting for air conditioning. It strikes a balance between comfort and energy efficiency. Here are some points to consider:
Cool mode
This is the most common and usually the default setting when you first turn on the AC. This mode sends cool air throughout your room and is great for cooling down an area after a long, hot day.
Since 72 degrees is generally agreed upon to be an ideal indoor temperature, most people would probably still feel comfortable setting their AC units slightly higher than this, perhaps at around 75.
If it's just you and your spouse, you may be fine with the temperature set at 75-77. But if you have kids and pets running around, or you're cooking and using your oven, these things can all raise the indoor temperature noticeably. So, you might find a temperature setting in the 72-74 range more comfortable.
While the Department of Energy recommends 78°F as an ideal setting, actual usage varies widely: Low end: Some households set their AC as low as 68°F (20°C) High end: Energy-conscious individuals may set temperatures up to 80°F (27°C) or higher. Average range: Most people tend to keep their AC between 72-76°F (22-24°C)
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.
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.
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.
Keeping your fan on AUTO is the most energy-efficient option. The fan only runs when the system is on and not continuously. There is better dehumidification in your home during the summer months. When your fan is set to AUTO, moisture from cold cooling coils can drip and be drained outside.
Set your air conditioning to the highest level that's comfortable. Turning our attention to the air conditioning unit itself, the most energy efficient action is to set the temperature to the highest value that's still comfortable (26°C during the day and 22°C when sleeping is often recommended).
Auto mode is similar to cool mode as the AC unit will work to cool the air down. However, unlike cool mode, once the room reaches the set temperature, both the compressor and fan switch off. This mode is another ideal mode for saving energy and money as once everything is switched off no electricity is used.
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.
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.
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.
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.
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.
This was the most efficient approach, and it led us to conclude the following: If you want to save energy without sacrificing much comfort, the best thing to do is to leave the AC unit running, but set its internal thermostat a little higher.
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.
leaving it on all day and night is better for the HVAC system because it's less taxing. Should you turn off your AC when on vacation? HVAC experts agree it's better to keep your AC on when you're on vacation, especially if you don't plan to leave any windows open.
Choosing the Best Temperature for Your Air Conditioner
You can also reduce your energy costs significantly by raising the temperature while you are at work, away from home, or asleep. For the greatest savings, consider setting your thermostat to: About 78 degrees while you are at home.
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.
During a heatwave, we recommend that you don't lower the AC's setting below 68°F. This is already quite chilly for most people, and many would consider it too cold. An air conditioner set this low risk of its coil freezing—and that's bad news because it indicates that the air conditioner is overworked.
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.