Should the AC and Recirculation Be Turned On When Using the Heater?
2 Answers
You don't need to turn on the AC when using the heater. The AC button is used for air conditioning adjustment. In summer, when you turn on the cold air, you can press the AC button to activate the air conditioning compressor for cooling. In winter, when using the heater, there's no need to press this button. The AC won't engage the compressor for heating, as the heater doesn't rely on the compressor to generate heat. Instead, it transfers the engine's heat to the interior of the car. Using the heater doesn't consume extra fuel: The reason the heater doesn't consume extra fuel is that it transfers the heat generated by the engine into the car. Even if you don't use the heater, the engine still produces heat, which is then expelled outside the vehicle. Therefore, using the heater has no impact on fuel consumption. Precautions when using the heater: Since the heat from the heater comes from the engine, prolonged use can produce toxic gases like carbon monoxide, which can be dangerous for passengers inside the car. If you notice any unusual air quality inside the car, immediately open the windows or doors to ventilate and expel the toxic gases. Additionally, when there is frost or fog on the car windows, you can also use the heater to remove it.
You actually don't need to press the AC button for heating! The warm air comes from the engine's heat and has nothing to do with the air conditioning compressor. Turning on AC just wastes fuel and puts extra load on the engine. As for recirculation mode: use it when you first get in the car and are shivering from cold - the heat builds up faster and temperature rises sharply. But after 10-20 minutes you should switch to fresh air mode, otherwise the cabin gets stuffy and windows fog up easily. I experienced this on a long drive - keeping recirculation on too long made me feel dizzy, and I only recovered after opening windows at a service area. This is especially important in humid southern regions, or your windshield will fog up in minutes like it's covered with white gauze.
