Is It Bad To Run AC In Idle? (Might Surprise You)

One of the things that are common among city drivers is that their cars usually have plenty of idle time, especially when you are now considering the time spent in traffic.

Of course, during that time, you are also running the AC, especially when it is in the middle of a hot summer day.

However, is it actually bad to run the AC while you are idling?

Find out if it is bad to run AC in Idle

Idling while the AC is on isn’t necessarily bad for your car because most cars can handle such a situation without getting damaged or without seeing significant wear and tear. However, idling with the AC on isn’t really as ideal as actually moving due to poor airflow and wasted power, among other things.

car air conditioner

If you tend to idle a lot while you are running your AC, don’t worry too much because this shouldn’t be something that is going to ruin your car now or in the near future.

While it might be true that it isn’t the most ideal situation to keep the engine running while the AC is turned on even when you are not moving, this shouldn’t be something that should leave lasting damage to your car.

Does AC work at idle?


The car’s AC is an important component that allows you to stay cool while you are driving. Not having a working AC isn’t the best situation you can put yourself in as a driver, especially when it’s the middle of a hot summer day.

This is why making sure that your AC is working properly is one of the best things you should do as a driver, as a working AC is great for your overall comfort.

However, one of the things that drivers often experience during busy hours in the city is idling, which is a state in which the engine is on, but the car isn’t moving. This is quite common in populated areas that are prone to traffic.

But does your AC still work whenever your car is idle?

Of course, the AC will still work when the car is idle. A car’s AC is designed to make sure that it is working under any kind of condition, as long as the components are working properly.

This means that, even if the car isn’t moving while the engine is running, the AC will still work properly.

However, there are some cases where the AC won’t work or blow cool air when you are idling.

It is quite normal for the AC to face a dip in terms of its performance when the car is not moving, but the dip is hardly noticeable. But what if the drop in performance becomes noticeable?

Why does my AC get hot at idle?

If you do notice that your AC gets hot at idle or when its performance drops significantly, there is a really good explanation for that. And the simple explanation we can give is that the AC is malfunctioning.

When the AC is not as cool as it should be during idle, the decreased cooling is not due to how the AC shuts down but is more likely due to how it lost capacity in terms of its ability to cool.

The circulation of freon throughout the entire system isn’t as effective when the car is idle due to how the pressure is lower. Pressure is what is needed for the refrigerant to move throughout the system, and the pressure is lower when the car is idle.

This produces a lower cooling effect that will make the AC lose performance.

Of course, the RPMs have a contribution here as well. When the vehicle is idle, the RPMs are lower. Because of that, the compressor won’t spin as fast as it should when it is moving.

This will restrict the refrigerant that should be circulating through the system, as freon relies on the pressure coming from the compressor to move around the car’s cooling system.

There is also the possibility that the airflow across the condenser coil is diminished.

When that happens and when the car is not in motion, the only airflow that the condenser coil will receive is the one coming from the engine fan, which is not as effective as the airflow coming from the condenser coil. This will result in a drop in the cooling.

But while such factors may drop the car’s cooling capacity when you are idling, the drop shouldn’t be too considerable to the point that you would notice it right away.

If the drop is actually quite noticeable to the point that the AC seems a lot warmer than it should, then there must be a problem with the car’s cooling system.

Is it bad to run AC in idle?

While we did discuss that the AC won’t perform as well as it should when the car is idling, does that mean that it is bad to run it when the car is idle? What does it mean for your car when you are idle, and the AC is running?

Well, for starters, there shouldn’t be a lot of reasons for you to think that your car is going to get damaged or is going to wear down if you are at idle and the AC is running.

This is due in large part to how most cars are engineered to make sure that they won’t get damaged when at idle, and there are several components that are running, such as the AC.

Of course, there are also some things that you should consider. The temperature under the hood might increase when you are idle, and the AC is running due to how bad the airflow is.

Remember that your car cools itself better when you are running, and this will drop considerably whenever you are idle.

Then there is the fact that the AC working will also push the components harder when you are at idle, and there is no way for the car to get the right airflow it needs to improve its cooling.

This is why you will notice that the temperature of the engine tends to be higher when you are idle.

Then again, this shouldn’t be a problem if all of the car’s components are working properly.

However, if one of the components of the car’s cooling system isn’t working as it should or has become quite worn out, there might be a chance that idling while the car’s AC is turned on can cause the vehicle to overheat.

Sources Idling with AC on

Is it bad to idle a car with an A/C on for 30 minutes?

Is it harmful to a car to run AC when parked? (idle, engine)