What is the ideal temperature for car air conditioning?
2 Answers
The most comfortable air conditioning temperature for the human body is 24-27 degrees Celsius, so it is generally appropriate to set the car air conditioning to around 26 degrees Celsius. To prevent "air conditioning sickness," if the air conditioning needs to be used for an extended period, it is advisable to open the car windows slightly at regular intervals to ensure fresh air inside the vehicle. Additionally, drivers should try to avoid using the air conditioning for too long, generally not exceeding 1 hour. Additional Information: 1. Regarding car air conditioning standards, the American Society of Engineers has established a comfort chart, suggesting that the most people feel comfortable at a summer temperature of 25°C and a relative humidity of 50%. In Japan, it is believed that the most people feel comfortable at a summer temperature of 19°C–23°C and a relative humidity of 60%–70%. 2. Car air conditioning engineers also refer to the above ranges and consider the effects of radiation heat from windows and car walls to establish car comfort environment indicators. They suggest that summer air conditioning can be set at 21-25°C, while winter air conditioning can be set at 25-28°C. It is also noted that the temperature inside the car should not differ too much from the external environment temperature, as this may cause discomfort to passengers. Generally, the temperature difference between the inside and outside of the car should be within 10°C for sedans and 8-12°C for large buses.
I think setting the car air conditioning between 22°C and 24°C is most appropriate, as the small temperature difference between inside and outside prevents the body from experiencing sudden chills or overheating. During summer heat, setting it too low (e.g., 18°C) creates a large temperature gap that may lead to catching a cold or discomfort after exiting the vehicle. A moderate temperature also prevents excessive skin dryness or increased sweating, which could distract driving. My routine is using recirculation mode for quick cooling (5 minutes), then switching to fresh air mode to maintain ventilation—this improves efficiency. Medium fan speed is ideal; higher settings create noise discomfort. Energy efficiency matters too—each 1°C drop increases fuel consumption by ~5%, so moderate settings save fuel. Long-term, this protects the AC system from overload issues. Remember to fine-tune based on personal comfort for optimal results.
