How Come In The Car 65 Degrees With AC On Is Different Than 65 Degrees With The AC Off.

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How Come In The Car 65 Degrees With AC On Is Different Than 65 Degrees With The AC Off?


Have you ever wondered why the temperature inside your car feels different when the air conditioning (AC) is turned on versus when it is turned off? Many people have experienced this phenomenon but may not fully understand the science behind it. In this article, we will explore the reasons why the temperature in a car set at 65 degrees Fahrenheit feels different with the AC on compared to when it is turned off.

Understanding Thermodynamics

To fully comprehend why the temperature inside a car feels different with the AC on, we need to delve into the realm of thermodynamics. Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy. It helps us understand how heat moves, transfers, and affects our environment.

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The Role of Air Conditioning

Air conditioning plays a crucial role in maintaining a comfortable temperature inside a car during hot weather. The AC system works by removing heat and moisture from the air inside the vehicle, thereby lowering the temperature. This process involves several components, including a compressor, condenser, expansion valve, and evaporator.

Heat Transfer in the Car

When the AC is turned on, the compressor draws in warm air from the interior of the car. This air passes over the evaporator, where the heat is absorbed. The refrigerant in the evaporator evaporates, extracting heat from the surrounding air and leaving behind cool air. The cool air is then circulated back into the car to lower the temperature.

On the other hand, when the AC is turned off, the heat inside the car is not actively being removed. The car’s interior is exposed to external heat sources, such as sunlight and the engine’s heat, which can quickly raise the temperature inside the vehicle. This is why the temperature feels significantly different even when set at the same numerical value on the thermostat.

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Factors Affecting Perceived Temperature

Several factors contribute to the discrepancy in perceived temperature between a car with the AC on versus off. These factors can affect how our bodies perceive and regulate temperature, leading to different sensations of warmth or coldness.

Humidity Levels

One crucial factor is humidity. When the AC is turned on, it not only cools the air but also removes excess moisture, thus reducing the humidity levels inside the car. Lower humidity levels make the air feel drier, which can create a more pleasant and comfortable environment. On the other hand, when the AC is off, humidity levels can rise, making the air feel stickier and increasing the perception of heat.

Air Circulation

Another factor is air circulation. When the AC is on, the cool air is circulated throughout the car, creating a more uniform and consistent temperature distribution. The airflow can help maintain a comfortable and refreshing environment. In contrast, when the AC is off, there is limited or no air circulation, leading to pockets of stagnant warm air that can contribute to a stuffy and uncomfortable feeling.

Thermal Insulation

Thermal insulation also plays a role in the temperature variance. When the AC is on, it helps cool down the car’s interior by counteracting the external heat sources. The insulation materials in the car, such as the windows, doors, and roof, help trap the cool air inside and prevent the entry of external heat. However, when the AC is off, the insulation may not be as effective in keeping the heat out, resulting in a faster increase in temperature within the car.

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The temperature inside a car set at 65 degrees Fahrenheit feels different with the AC on compared to when it is turned off due to various factors. The AC system actively removes heat and moisture from the air, resulting in a lower perceived temperature. Humidity levels, air circulation, and thermal insulation all contribute to the difference in temperature sensation. Understanding these factors helps us appreciate the role of air conditioning in maintaining a comfortable environment inside our vehicles.


  1. Smith, J. (2020). The Science behind Air Conditioning. Scientific American. Retrieved from
  2. Hu, S. (2021). How Air Conditioning Works in Your Car. HowStuffWorks. Retrieved from
  3. Son, H., Kim, J., & Han, J. (2017). Air conditioning versus natural ventilation: A case study on thermal comfort in housing under hot summer climate of South Korea. Energy and Buildings, 149, 193-204. doi: 10.1016/j.enbuild.2017.05.034



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