Will Your AC Work If It Is Cold Outside, Like Under 65 Degrees? 

Although air conditioners are typically used on hot summer days, they may be used in cold weather in some cases, such as to get fresh air, test the unit, or remove the clammy smell. Will your air conditioner work if it’s cold outside?

Generally speaking, your AC may not work properly when the outside temperature is under 60 degrees since it may cause damage to your machine. But it is OK if your AC has a heat mode. In most models, running an AC below 65 degrees Fahrenheit but above 60 degrees Fahrenheit is permitted.

In this post, I will explain why it is bad for an AC to work in cold weather and what outside temperature is too cold. If you are thinking about running your AC in winter, you must take some minutes to read it!

What outside temperature is too cold for an air conditioner?

As I stated at the beginning, 60 degrees is too cold for a standard AC to work properly. This is based on data gathered from numerous AC manuals.

Some brands or models may allow you to run it at 59 degrees, while others recommend stopping at 65 degrees. However, most models are safe at 60 degrees.

The best way to determine what outside temperature is too cold for your specific machine is to consult the instruction manual or the manufacturer’s website.

It’s worth noting that some high-tech air conditioners include a heating element that can be used as a heater on cold days. In this case, you must switch your air conditioner from “cool mode” to “heat mode.” If you do not do this, your air conditioner will not function properly.

Furthermore, the best time to turn on an air conditioner is when the indoor temperature is around 75 degrees, but it should work as long as the temperature is above 60 degrees.

Why does running an AC in cold weather may damage it?

The reason why you should not run an AC under 60 degrees is that you may run the risk of damage. There are two main culprits of potential damage.

Lubricant oil gets thicker

Air conditioners include a compressor, which is in charge of moving refrigerant between evaporator and condenser coils. There is some lubricant oil inside to ensure that it can work at high speeds.

There is some lubricant oil inside to ensure that it can work at high speeds.

If you run the air conditioner when it’s too cold outside, the oil won’t be able to properly lubricate the compressor because it can’t move smoothly, increasing the likelihood of a malfunction.

The light-grade oil may solve the problem in winter but will cause issues in summer because the oil may evaporate. Since people don’t always run AC in winter, manufacturers only use heavy-grade oil in their products.

Coils freeze up

The increased thickness of lubricant oil will cause the internal pressure to drop, leading to freezing on the evaporator and condenser coils. 

When the coil becomes frozen, your AC will stop working, and the ice will take a long time to thaw. As you know, if your AC freezes up frequently, its lifespan will be reduced significantly. 

Hence, your AC will not work properly in cold weather due to the reasons in this section.

Running an AC under 65 degrees

Running an AC under 65 degrees

Many customers are curious about whether or not they can run an AC under 65 degrees.

Based on what we discussed above, it is generally safe to do that as long as the outside temperature is above 60 degrees or the manufacturer doesn’t forbid it. 

However, to proceed it safer, it is not advisable to turn it on when the temperature rises to 65 degrees suddenly because the lubricant oil may not have adequate time to return to its normal state and the ice buildup needs some time to thaw.

It is preferable to run your air conditioner for at least three or four days until the outside temperature rises above 60 degrees.

How to cool or refresh your house in cold weather without an air conditioner?

Since you have understood your AC may not function well at low temperatures, you need to look for other solutions for cooling or refreshing a house.

Open the window

This method can be applicable to every home. By opening the windows in each room, the air outside will get into the house and take away the heat and moisture lingering in the room. 

The best part is that it doesn’t consume any energy, which is environment-friendly and pocket-friendly.

Use a fan 

If you live in a room with no window, you can make use of a fan to refresh it. The rotating blades can move the stagnant air and create a breeze that can take away the heat on your body. 

That is to say, it can make you feel cool even if the room temperature doesn’t change.

Utilize a dehumidifier 

Winter months are typically dry, but this is not the case for houses that have experienced water damage or in extremely humid areas.

High humidity leads to clammy air, the growth of mold and dust mites, headaches, and other symptoms. 

Running a dehumidifier can remove the excess moisture, and you will feel much more comfortable when the moisture level falls since it can promote the evaporation of sweat.

Close the blinds and curtains

Those who find their houses have a higher temperature than outside can close the curtains or blinds during the day. It can block out the sunlight, which can increase heat inside the house.


When the outside temperature drops too low, your air conditioner may not function properly. When the temperature is below 60 degrees, the lubricant oil in the compressor can move quickly, causing the coils to ice up. Both scenarios can cause damage to your machine.

If you plan to run your air conditioner below 65 degrees, make sure the last three or four days have been above 60 degrees.

If you want to dehumidify or cool the air, there are other options besides running your AC when it’s cold outside.

About The Author

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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 dozens of products in person, like 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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