What is the ideal temperature for car air conditioning in summer?

[AryaMarie]

In summer, it is generally recommended to set the car air conditioning to around 25°C, as the comfortable temperature range for the human body is between 24°C and 27°C. Additionally, the local weather temperature should be considered, and the indoor-outdoor temperature difference should not exceed 5°C. Here is some relevant information: 1. The most suitable air conditioning temperature for the human body should be between 24°C and 27°C, with a minimum not lower than 22°C. The indoor-outdoor temperature difference should not exceed 5°C, and the air conditioning temperature at night should not be set below 24°C. If the air conditioning is set too low, the indoor temperature may become excessively cold, leading to 'air conditioning sickness,' which can cause symptoms such as colds, coughs, fever, and fatigue. 2. Many people, when faced with a hot car, immediately start the vehicle, turn on the air conditioning, and set the fan speed to the highest level to achieve the fastest cooling effect. However, this approach does not effectively lower the interior temperature quickly. 3. The correct method is to first open all four windows to allow cross-ventilation, helping the interior temperature to equalize with the outdoor temperature as quickly as possible. Then, close the windows and turn on the air conditioning in recirculation mode for cooling.

[Annie]

I've been driving for over a decade, and I find setting the AC between 24-26°C in summer is most comfortable. When the car's been baking in 40°C heat outside, never blast the AC at 16°C immediately - the drastic temperature change can easily cause dizziness. My routine is to open windows for ventilation first for two minutes. After starting the AC, I use external circulation to expel hot air, setting the temperature at 24°C with medium fan speed. Once cooled down, I adjust to 26°C with low fan speed for maintenance - this saves fuel and prevents colds. Remember never to leave lighters near the windshield as high temperatures may cause explosions. When carrying elderly or children, set the temperature one degree higher, and especially avoid having rear vents blowing directly at passengers.

[KathrynRose]

I think setting the car AC around 25°C in summer is just right. Once I set it to 22°C and ended up with heatstroke after getting out - a temperature difference over 15°C is too harsh on the body. Now I always keep the temperature dial between 24-26°C, and it's even more comfortable on long drives when paired with seat ventilation. Different car brands have varying AC performance - for instance, German cars cool faster so you can set it slightly higher, while Japanese cars may need lower settings. Also remember to switch to external air circulation every two hours, otherwise high CO₂ concentration inside can cause drowsiness. Never sleep in the car with AC running - there have been news reports of carbon monoxide poisoning cases.

[MacAsher]

In summer, the air conditioning temperature should be adjusted flexibly. My experience is: set it to 24°C with high fan speed for quick cooling when you first get in the car, then adjust it to 26°C with low fan speed after 10 minutes to maintain. The perceived temperature is actually related to humidity as well. In the humid and stuffy south, you can set it one or two degrees lower. Check the air conditioning filter every month; if it's dirty, it will affect cooling efficiency. I've seen people set it to 20°C and still complain about the heat, only to find out it was due to refrigerant leakage. If the thermometer shows 26°C but it feels like 30°C, go for a check-up immediately. During the break-in period of a new car, avoid setting the temperature too low to protect the compressor.

[OMaria]

25 degrees is my golden temperature. This setting is because keeping the temperature difference within 10 degrees is the healthiest, preventing blood vessel contraction. Setting the AC too low increases fuel consumption significantly—I've tested that 26 degrees saves 0.8 liters per 100 kilometers compared to 22 degrees. The sequence when getting in the car matters: after starting, open the windows and turn on the fan first, then activate the compressor after two minutes. Don't use recirculation mode continuously for over an hour. For cars with automatic AC, simply pressing AUTO is the most hassle-free, as it automatically adjusts fan speed based on sunlight intensity.

[OJude]

I usually set the car air conditioning between 25-26°C in summer, mainly considering two factors: First, the engine load - setting the temperature too low causes frequent compressor cycling. Second, human comfort - 26°C is just right to avoid sweating when wearing short sleeves. Be careful not to direct the vents at your face, as it's particularly harmful to eyes. I've seen cases where setting 18°C caused evaporator icing. For long trips, I recommend increasing the temperature by 1°C every hour to adapt to temperature changes. You can also adjust for different times - 24°C during the hottest noon hours, then 27°C by evening.