Should the A/C be turned on when using the car's heater?

[TannerAnn]

Turning on the heater does not require pressing the A/C button. If the A/C button is pressed, the car's air vents will deliver cold air. Below is an introduction to the A/C button: 1. The full name of the A/C button is 'air condition,' translated as the air conditioning button. Its function is to serve as the switch for the car's air conditioning cooling system. Whether it's a manual or automatic air conditioning system, the car's air conditioning system includes an A/C button on the interior control panel. The A/C button is a crucial component of the car's air conditioning system, which is designed to cool, heat, ventilate, and purify the air inside the car. 2. When using the heater in winter, pressing the A/C button does not assist in heating. On the contrary, the operation of the compressor will cause unnecessary power loss. Therefore, when using the heater, the car's compressor can be completely turned off (i.e., there's no need to press the A/C button). Not pressing the A/C button will not have any impact on the heater's performance.

[KevinRose]

As an ordinary person who drives frequently, I find this question very practical. When turning on the heater, you generally don't need to press the AC button because the warm air in the car mainly comes from the heat generated by the engine, which is blown out by the fan. AC stands for air conditioning compressor, primarily used for cooling and dehumidifying. Every time I drive in cold weather, I simply adjust the temperature knob to the warm zone or the red mark, set the fan to an appropriate speed, and immediately feel warm and comfortable. Turning on the AC would only increase the engine load and burn more fuel, which is not only costly but also environmentally unfriendly. However, when heavy fog obstructs visibility in winter, turning on the AC along with the heater can quickly defog the windshield—just turn it on temporarily and then switch it off. This habit helps me save fuel, drive with peace of mind, and visit the repair shop less often. After all, fixing a faulty air conditioning system can be expensive, and regularly checking the air filter can maintain heater quality and extend its lifespan. In short, turning on the AC while using the heater is mostly unnecessary—driving comfortably and economically is the way to go.

[StBrielle]

I have some knowledge about cars. Turning on the AC when using the heater is not necessary. Simply put, a car's air conditioning system consists of a cooling component that relies on the compressor (the AC button) and a heating component that uses the engine's coolant circulation to heat the core. When you turn on the heater, the fan blows hot air without needing to activate the AC. However, in humid weather, turning on the AC can speed up dehumidification and prevent fogging, which is particularly beneficial during the rainy season in southern regions. When operating the system, set the temperature higher, select the heating mode, and toggle the AC as needed to save fuel—this is a smart practice. I've noticed that using both the heater and AC increases engine load, raising fuel consumption by about 5%. This not only costs more but also affects performance. Proper settings can extend the lifespan of your AC system. Regular maintenance of the heater ensures efficient operation. Remembering these small details can make your car more durable. Understanding the system helps avoid minor issues, making driving smoother.

[George]

Turning on the AC while using the heater is redundant, increases fuel consumption, and wastes resources—I never use it. The warm air comes from the engine's residual heat, which is free and eco-friendly. Using the AC consumes extra fuel and increases emissions, making it an unwise choice. When operating, simply adjust the heater without turning on the AC to save fuel. Make it a habit to use the heater in cold weather to prevent fogging, and only briefly activate the defogger when necessary, turning it off afterward to protect the environment and save gasoline. Simple driving reduces waste and is more planet-friendly.

[SanAlice]

When I first started driving, I also asked about this basic knowledge - you don't need to turn on AC for heating. The hot air comes from the engine heat blown by the fan, while the AC button is responsible for cooling and dehumidification. Don't confuse them. Set the temperature to warm, turn on sufficient fan speed for comfort, but if fogging is severe, activate the defogging mode (usually linked to AC). Turn it off after a short while. Remember these operations to save fuel and ensure safety. Beginners should read the manual more to adapt to different car models. For automatic AC, just adjust the temperature. Maintaining these habits makes driving easier and more economical while reducing repair troubles.