What Temperature To Set Air Conditioner in Summer? (How To Set AC)


Having an air conditioned home on an oppressively hot summer day is like finding an oasis in the desert.

The relief from the heat and humidity, and the ability to comfortably relax is a welcome idea after a long hot day. Everyone wants to be comfortable, but at what cost? What is the best AC temperature for energy savings?

In my experience as a licensed HVAC contractor, home owners are constantly asking this question. While the Department of Energy has a recommended temperature, there is no cut and dry number that works for everyone.

There are many variables that have to be considered to find what is a good temperature for air conditioning for yourself and your home. In this article, I’m going to explain how air conditioners work and cover several factors to evaluate when determining what is a good temperature for air conditioning.

What Is The Best AC Temperature For Summer?

The best temperature for AC in summer is 78-degrees to be as efficient as possible.

Ideally you want to set your temperature as high as comfortably possible if you’re trying to save a buck. The closer the indoor and outdoor temperatures are to each other, the less energy is required to cool the house.

In my experience, 78 degrees is higher than what most people are comfortable with. It’s usually somewhere around 72-75 degrees, but these are average AC temps and don’t necessarily work for everyone.

If you live in a more humid environment, you are more likely to set your thermostat lower to help combat the increased discomfort that a higher relative humidity brings.

Generally, you want 30-50% humidity for comfort and to help reduce mold growth. You can read our guide on the symptoms of mold in air ducts system here.

It’s also recommended to adjust your temperature throughout the day when you aren’t using it. If you’re away for the day, you can set your temperature higher, up to 85-degrees, to reduce energy use as much as possible. You can even do this at night as long as you’re able to comfortably sleep at around 82-degrees.

Although it is efficient to do so, be mindful that it takes a significant amount of time to remove that amount of heat from your house and the air conditioner may run for an extended period of time trying to catch up.

Understanding Air Conditioning

Air conditioners absorb heat from the home and move it outside where it is rejected.

Warm air from the house is exchanged and absorbed by the evaporator coil, moved to the outdoor unit where it is compressed, and moved again to the condenser coil where the heat can be rejected to the outside air.

Not only does this cool the house, but it also removes humidity from the air. The warm air moving through the cold evaporator coil causes condensation to form on the coil. Just like a cold glass of ice water sweats on a hot day.

Your thermostat reads the indoor air temperature and closes a switch telling your air conditioner when to come on. Some smart thermostats can read both air temperature and relative humidity and can adjust your temperature accordingly.

RELATED: Why AC Has A Musty Smell?

Factors To Consider When Picking AC Settings For Summer

Several things can affect the best temperature to set your AC on.

If you live in a warmer climate with high humidity, you are probably going to set your thermostat lower to help lower the humidity in your house. When the humidity is high, our sweat cannot evaporate which makes us feel warmer and uncomfortable. 

If you live in a drier climate, your sweat can evaporate properly and higher temperatures can feel equally as comfortable.

Your home’s insulation is another factor that can impact the best temp to set your AC. A properly insulated home helps prevent infiltration and lowers the cooling load. Because your AC removes heat from your living space, we want to keep as much heat-energy out as possible in the summer.

Poor insulation allows heat from the outside and the attic to infiltrate your home and increase the amount your AC has to run to keep up. On significantly hot days, your AC may not be able to reach your set temperature and will run continuously.

Read Also: What Are The Highest Rated Spray Foam Insulation Kits?


How to Save Money With Your A/C Temps

The best way to save money while running your AC is to keep the temperature as high as you can comfortably.

The closer you set the thermostat to the outdoor temperature, the more money you will save. Allowing your temperature to increase when you aren’t around helps as well because it’s not using unneeded energy.

Installing a ceiling fan is also very helpful in reducing energy consumption. Ceiling fans help circulate the air and can allow you to set your thermostat higher, up to 4-degrees higher. Because they use way less energy and can allow you to stay comfortable while keeping the thermostat higher, it’s a great way to save. I invite you to read our guide on how to install a ceiling fan written by a licensed electrician.

A programmable thermostat or smart thermostat is also beneficial. It can automatically adjust your temperature to your regular schedule and some thermostats will even use your location to turn your AC on when you’re getting close to home. It takes the complication of constantly having to remember to adjust your thermostat out of the equation and simply does it for you.

Read Also: What Are The Best Programmable Thermostats Under $50?

programmable thermostat

Regular Maintenance and Efficiency

A properly maintained HVAC system can reduce your energy costs.

Air conditioners absorb and reject heat to properly cool a home. Sufficient airflow is essential in allowing this to take place. Both indoor and outdoor coils must be clean to efficiently operate. Efficient operation helps maintain A/C temps in summer.

Your condenser coil (outdoor coil) will get clogged with pollen, grass clippings, dryer lint, and other debris. Most of the time, you can take a garden hose and clean it pretty well. Sometimes a chemical cleaner is necessary to remove excessive build up. NEVER use a pressure washer, it will flatten the coil fins and cost you a pretty penny to repair.

Your evaporator coil (indoor coil) can also get clogged with anything that makes it past the air filter. Mold and mildew also grow here and can cause bad odors and poor air quality, so it’s not a bad idea to check and clean it regularly. Evaporator coil cleaners work great here and require no rinsing.

dirty condenser coil

Final Thoughts

If you aren’t sure what temperature to set your AC to, start with 78 degrees.

Increase or decrease one degree at a time until you find a temperature that you feel comfortable with. It also helps to keep an eye on what the outdoor temperature is supposed to be and try to adjust accordingly. Remember, the closer to the outdoor temperature, the less energy is required to cool your home.

Install a ceiling fan in your living space to help your AC run more efficiently and regularly maintain your AC equipment to ensure optimal performance. Have your thermostat adjusted while you’re away to make sure you aren’t wasting energy.

Following these recommendations is sure to help you reduce your energy bill and be as comfortable as possible.

RELATED: Why My AC Keeps Freezing?

Frequently Asked Questions

What Is The Best Temperature During The Day?

The best temp for AC during the day is 78-degrees while home and 82-85 while away.

What Is The Best Temperature At Night?

The temperature setting for AC at night is 82 degrees, but most people find that uncomfortable to sleep at. You may need it set lower depending on your level of comfort and the climate you live in.

How Can I Reduce The Costs During Summer?

The best way to reduce your air conditioning bill in the summer is by increasing your thermostat temperature. If that doesn’t work for you, try installing a ceiling fan and maintaining your AC equipment. Replacing your thermostat with a smart thermostat will help as well.

How Does Insulation Affect An Air Conditioning System?

Your homes insulation is it’s first line of defense in maintaining efficiency. It’s the barrier that keeps the heat out and allows your home to stay comfortable longer. Poor insulation allows heat infiltration and will cause your system to work harder to maintain temperature.


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