No hot air in car air conditioning is caused by issues such as cooling system failures. The reasons for no hot air in car air conditioning include: Lack of coolant in the cooling system, which is the most common cause of no hot air in car air conditioning. A faulty thermostat can prevent the water temperature from rising, resulting in no hot air. A malfunctioning heater valve can block coolant flow to the heater core, leading to no hot air. A clogged heater core can slow down the coolant flow inside it, reducing heat supply and causing no hot air in the car air conditioning. Car air conditioning cooling: Requires the use of a compressor, and the operation of the compressor consumes a significant amount of fuel. In winter, the principle of heating is different—it does not use a compressor but instead utilizes the engine's coolant temperature to generate heat. This is achieved by using a blower to direct the heat released by the engine into the cabin. Although the blower's operation requires electricity, which increases engine load and fuel consumption, it is far less than the fuel consumption level when using air conditioning in summer. However, avoid turning on the heater immediately after starting the car or while the engine is still warming up, as the engine is not yet hot, and the air blown in will be cold, wasting electricity and increasing engine load. It is also best not to use the heater while idling.
