Does Using the Heater While Idling Consume Fuel?

[EmersonFitz]

Cars need to start the engine to generate warm air when stationary, which burns gasoline to produce heat. Below is how the car heating system works: 1. Compression Process: The compressor draws in low-temperature, low-pressure refrigerant gas from the evaporator outlet and compresses it into high-temperature, high-pressure gas before discharging it. 2. Heat Dissipation Process: The high-temperature, high-pressure superheated refrigerant gas enters the condenser, where it condenses into a liquid due to reduced pressure and temperature, releasing a significant amount of heat. 3. Throttling Process: The higher-temperature and higher-pressure refrigerant liquid passes through an expansion device, increasing in volume while pressure and temperature drop sharply, exiting as a mist (fine droplets). 4. Heat Absorption Process: The mist-like refrigerant liquid enters the evaporator. Since the refrigerant's boiling point is much lower than the evaporator's internal temperature, the liquid evaporates into gas, absorbing substantial heat from the surroundings. The low-temperature, low-pressure refrigerant vapor then re-enters the compressor.