Should you shut off the A/C before turning off your car’s engine?

Shutting off the air-conditioning system a few minutes before stopping the vehicle does not necessarily protect the engine, as believed by many drivers. However, doing so is still highly recommended to protect your health and to avoid mold growth in your car’s interior.

The air conditioning system is indispensable in today's modern cars, especially in countries with a hot climate such as the Philippines. However, not all drivers know how to use car air conditioner properly and this affects your car maintenance badly. Failure to use and preserve the A/C in a proper way would impose negative effects on the durability of the car and more importantly on the user’s health.

The basic components of an air conditioning system consist of a compressor, a condenser, a desiccant, a throttle, a vaporizer and the coolant gas. The compressor is connected to the car engine through a cassette wire, and it only works when the engine starts. Therefore, many drivers think that the air-conditioner which consumes a significant amount of power and fuel would create extra weight for the car engine to carry, especially in the ignition phase. They believe that in order to protect and preserve the engine, it is better to turn off the air conditioner before stopping the car engine and to turn it on after the next ignition, rather than turning the engine and the A/C on and off at the same time.

Many drivers believe that in order to protect and preserve the engine, it is better to turn off the air conditioner before stopping the car engine

However, according to Howstuffworks, automotive air conditioning system, no matter whether it is on or off, does not affect the engine of the car. Thanks to the increasingly modern technology on today's car models, whenever you start your car, the ECU will automatically switch off all other vehicle support systems to focus the fuel and battery power entirely to the engine. You could have also noticed that when the engine starts up, devices such as lights and radios will automatically shut off for a brief moment, and the air conditioner is no exception.

According to Howstuffworks, automotive air conditioning system, no matter whether it is on or off, does not affect the engine of the car

You now know that shutting down the air conditioner before or after stopping your car does not affect the operation or the durability of its engine. So if you want to enjoy the cool air to the very last minutes of your way to work or back home, it won’t hurt your precious car.

However, your health, which is even more precious, could be affected if you or someone in your car stepped from the cooled cabin to the hot atmosphere of a midsummer day and get a heat shock. If this concerns you, then it is recommended to turn off the A/C for a few minutes before you arrive, so that your body could gradually get used to the outside temperature.

You now know that shutting down the air conditioner before or after stopping your car does not affect the operation or the durability of its engine

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In addition, turning off the car air conditioning for a few minutes before stopping the car also allows the A/C air doors, which often accumulate moisture due to low temperature, to dry and avoid mold growth in the car interior. This definitely helps if you are experiencing an unpleasant odor every time you step into the car (which is most likely caused by mold).