Red represents hot air, blue represents cold air, and the white part in the middle represents moderate temperature. If you want to turn on the air conditioner for cooling, you need to turn the button to the blue part. If you want to turn on the hot air, you need to turn the button to the red part and turn off the AC switch.
Heating air in automobile air conditioner will not increase fuel consumption, because after the automobile is started, the warm air is not generated by the air conditioner, but the heat of the engine itself is transported to the car in the form of water heating. This part of the heat is generated by the car itself, not extra. Even if it is not transported to the car, it will be discharged into the air.
To turn on the warm air of the air conditioner, you need to start the car first. After the car is warmed up, the warm air conditioner can only be turned on after the engine temperature rises. At the same time, external circulation is needed to let the cold air be discharged quickly. You can turn off the external circulation after 2~3 minutes, and then switch to the internal circulation, so that the temperature inside the car will rise rapidly.