Can I Run AC While the Car is Parked?

running ac while car is parked

It can be challenging to leave the air conditioner on while your car is parked and the engine is idling. In this article, we’ll talk about whether or not leaving the AC on while the engine is idling can damage the AC and engine in your car.

Can I fall asleep in my car while the air conditioning is on? Running your car’s air conditioning while parked is completely acceptable. Driving consumes a lot more fuel than simply waiting in traffic or at a stop sign.

However, keep in mind that the additional drag from moving air will cause the car to use even more fuel if it is moving while the AC is operating. How long can I stay in this situation, then? To learn more, keep reading.

Can You Leave AC on While the Car is Parked?

It is important to consider two circumstances. The engine is turned on after the first stage when it is off.

Because the compressor and engine are connected by a serpentine belt, as you are aware. When the engine is turned off, the car will switch to using the battery to turn on the AC blower (if the battery is still charged).

As a result, you will receive air through the AC vents, but it will either release fresh air or circulate the air inside the vehicle.

On the other hand, there is nothing to be concerned about if the car is parked and the engine is running. The compressor is operating when the engine is in the running position, so the AC will continue to produce cold air.

Keep your car’s engine running and the air conditioning on if you don’t care about draining the gas tank while it’s parked.

Never use the AC when the engine is off because doing so drains the battery. You will soon have a dead battery if you continue doing this.

How Long Can I Keep My Car Ac on While My Car is Parked?

Several factors determine how long you can leave your car’s air conditioning on while the engine is running but it is parked. The first determining factor will be the kind of car you drive and its cooling system.

running ac while car is parked

If the vehicle is modern and has climate control, the air conditioning system is well-equipped with sensors that carefully manage the fan speed so as not to put too much strain on the engine.

So long as your car has enough fuel, modern vehicles with climate control systems can maintain the AC for up to two hours while idling in a park. Also, modern cars also have a remote start feature that can start the engine from a key fob or a mobile phone application. The air conditioning and climate control operate as well with remote start.

In cars, remote starting only operates for a maximum of 35 minutes, and only for a maximum of 5 to 10 minutes by default. AC, therefore, stops when the remote start. The engine must then be started manually after that.

Traditional air conditioning systems without sensors are still used in older cars. So, old cars with IC engines cannot idle for more than 30 minutes as they will overheat and deteriorate their performance.

The outside temperature will also be important. If the weather is hot, the car’s air conditioner will have to work harder to keep the car cool, which will eventually cause it to use more fuel.

What Are the Pros and Cons of Running the AC While Parked?


When you keep your car cool while not driving, your air conditioning will last longer and cost you less money overall.

When the air conditioner is on, any animals or young passengers will be much more comfortable.

Running your AC while parked will assist in keeping bugs and other debris off the windshield and windows, making it simpler to drive safely once you’re ready to move again.


It can use up more gas than usual (although not by much), so if you’re already low on gas, it could cause issues later if you need more fuel while driving somewhere else.

It can consume more gas than usual, so if you’re already low on gas, it could create issues later if you need more fuel while traveling somewhere else.

Can Car Overheat If AC Runs While the Car is Parked?

If the AC is running while the car is parked and the engine is running, the interior may become too warm. When the engine is idling, there is not enough airflow through the radiator. Since the coolant is not cooled down to a lower temperature as a result, the car overheats when the AC is turned on with the engine running.

Air can circulate through the radiator without a fan by moving at a specific speed. The engine can’t get enough air to cool it down at stops or slow speeds. Therefore, when a car is stopped and the AC is on, there is a chance that the engine could overheat.

running ac while car is parked

In an engine cooling system, the following components play an important role:

  • Water pump
  • Radiator fan
  • Thermostat

The water pump is in charge of moving the coolant through the radiator. A serpentine belt that is powered by the engine’s crankshaft drives the water pump. The water pump’s speed rises as you drive the car faster in order to keep the engine’s operating temperature constant.

The water pump won’t be able to generate enough coolant flow while the engine is idling if it has issues like a damaged impeller or a damaged pulley/belt. Corrosion on the impeller or damaged bearings can cause a water pump to malfunction.

Less airflow over the radiator when a car is parked necessitates the radiator fan to run at a higher speed while the engine is idling. In that case, you should inspect the radiator’s front to see if any dirt or debris is obstructing the airflow. Insufficient air will not pass through the radiator when the engine is idling if it is clogged.

As a result, you should check the temperature gauge while driving with the air conditioning on because an overheated engine can cause its parts to wear out more quickly.

Will My Car Battery Die If I Leave the AC On?

Whether or not the car’s air conditioning system is powered by the car battery is dependent.

If so, the car battery will indeed die quickly because AC draws too much power from the battery. The battery will soon run out of power and eventually die because it has a finite amount of capacity to run.

No, the car battery won’t die even if you leave the AC on all day long if the engine is running and all other electrical systems are functioning properly.

The fuel is used by the AC system to run and create cold air when the engine is running. How long the AC runs in this manner will now depend on how much fuel is still in the fuel tank.

Conclusion: Can I Run Ac While the Car is Parked?

In my opinion, it is slightly more affordable to book a cheap hotel room than to burn gas and damage your car by sleeping in the a/c of your car. Additionally, you have much more comfortable sleep.

If the car is parked, the AC will run for a number of hours depending on whether the engine is running or not. So, if you’re not driving but still using the air conditioner, make sure it’s not drawing power from the battery; instead, start the engine.

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