Can I Sleep In My Car With The AC Running?

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Can I sleep in my car with the AC running? The short answer is YES, you can sleep in your car with AC running, but it’s not advisable. We’ll discuss why below!

A car isn’t just a means of getting from one point to another for a lot of us. It can be a place to take a quick nap on a hot summer afternoon or where to rest during long interstate drives.

A recent study shows that “trucks drivers can sleep up to 8 hours inside their cars daily.” It is, therefore, imperative that we know how long we can sleep or whether or not we should sleep in our cars, especially with the AC running.

Can I Sleep In My Car With The AC Running?

The answer to the question is yes. You can jump into your car for a quick nap or hours of sleep, but there are things to consider.

The first thing is to check if you have enough gas or electricity to power the vehicle for as long as you want to.

You should also ask yourself if it is safe to sleep in your vehicle with the A.C running. Research has shown that sleeping in your car with the A.C running can be fatal.

Don’t panic, guys. Your car’s A.C isn’t out to end your life unless there is a problem with it. Let us dig in and discuss some of the reasons you shouldn’t be sleeping in your car with the A.C running.

Why You Shouldn’t Sleep in Your Car with the A.C Running

Can Your Car A.C Kill You

Asides the fact that a car is never that comfortable to sleep in, you run the risk of overheating your car. Since many car’s radiators are backups to the car’s expected motion, this can lead to damage to the vehicle’s engine.

Also, any slight leak in the exhaust system can kill you. Now, if you use an electric car, you can ignore the part of exhaust fumes choking you to death, but the case of your car overheating shouldn’t be overlooked.

Can Your Car A.C Kill You?

Research has revealed that sleeping in a car with the AC running can be fatal due to carbon monoxide poisoning.

Carbon monoxide is an odorless, highly poisonous gas. It is the by-product of the fuel your car uses. If, for instance, there is an issue with your car’s exhaust and it is not able to altogether remove this gas, it may find its way back into the car as you sleep and suffocate you.

Apart from the fact that your car may not be ultimately removing carbon monoxide, your AC system may be flawed and have some leaks you are unaware of and may be too weak to refresh the air inside your car entirely. This will lead to increased carbon monoxide levels.

Carbon monoxide reduces the blood’s ability to carry oxygen to your cells and causes them to die due to short supply or lack of oxygen, which can lead to brain damage and ultimately death.

What is even more dangerous about this gas is that it is completely odorless and causes you to fall asleep. I know you want to sleep, but you don’t want that kind of sleep.

Read Also: Can I Sleep In A Car With Windows Rolled Up?

Can Leaving Your AC Running Damage Your Car Battery and Engine?

Why You Shouldn't Sleep in Your Car with the A.C Running

Now let us talk about the health of the engine that is left running for hours on end when you are sleeping with the AC running. It is likely going to run the car’s battery down, depending on how long the A.C is allowed to run while you sleep.

If you’ve read our article about how long a car can stay without starting it, you will better understand how the battery affects the functionality of a car. If you haven’t, you can read it here.

So, if you leave your car AC running for hours without the car being in motion, you run the risk of damaging your car’s battery.

The engine can also overheat, causing damage to the radiator if left for an extended period running without movement. The car’s fans work as coolants when it is in motion.  Also, the air from outside cools the engine when the car is in motion.

The risk of overheating is higher if the car is in an enclosed space such as a garage.

So, on whether or not you can sleep in your car with the AC running, you most definitely can. But make sure that your exhaust system is whole with no leaks and the tailpipes blows exhaust well.

Be sure not to run the AC in an enclosed garage or porch even with the doors open.  Let me reiterate the point that the exhaust fumes can kill you.

If you must sleep in the car, please do so without the AC running as this can not only damage the car; it can, in many cases, be fatal due to carbon monoxide poisoning.

Instead, you can get an electric fan that can run through the night without damaging the car’s engine or batteries and keep your windows down to enable you to get fresh air.

Be sure that you’ve exhausted the options of getting a hotel or any other place to sleep before you finally decide on sleeping in the car.

Not only will you get better sleep inside a room, but the risk of getting suffocated by carbon monoxide will also be drastically reduced if not eliminated. Not to mention the expense of fixing a car should it get damaged by running your AC while you sleep.

It is not worth it when put side by side with the disadvantages and health risks it can pose.

Read Also: Can You Pressure Wash Your Car Engine?


In my opinion, is it is marginally cheaper to get a cheap hotel room than sleep in your car with the AC running, rather than expend gas and cause unnecessary wear and tear to your car. You also get to sleep a lot more comfortably.

If it is an all-electric car and is connected to a power source, you can have a go at it, but wear and tear also applies.

If you must sleep in your car, maybe because there’s no hotel nearby, then ensure you turn off your engine before sleeping and leave room for ventilation.

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