Should Car Air Conditioning Use Internal or External Circulation in Summer?
5 Answers
Whether to use internal or external circulation for car air conditioning in summer depends on different situations: 1. When the external air quality is poor, to prevent harmful gases from entering the cabin, it should be set to internal circulation; 2. When driving on the highway for a long time, to prevent the oxygen level in the car from decreasing, alternate between internal and external circulation. Functions of air conditioning: 1. Achieve cooling effect by continuously transforming and circulating refrigerant; 2. Use engine coolant, waste heat, or heat generated by a burner as a heat source for heating, which is then warmed by the heater and blown into the car by the blower to raise the temperature for heating; 3. Draw fresh external air into the car for ventilation and air exchange to prevent window fogging.
In summer when using the air conditioning, I personally prefer to start with recirculation mode to cool down the car quickly, especially after being parked under scorching sunlight - this way the cold air kicks in faster and the cabin becomes comfortable within minutes. Then I switch to fresh air mode for ventilation, introducing outside air to prevent odors or moisture buildup inside. During hot summer days, keeping recirculation on continuously might save some fuel but compromises air quality and tends to fog up windows. When driving in the city, I'm particularly mindful of exhaust fumes from surrounding vehicles, so I'd rather switch modes more frequently. On highways though, it's better to maintain recirculation longer to keep the cabin cool. The key is to flexibly alternate between both modes rather than lazily keeping windows closed all the time.
I think the use of air conditioning in summer depends on the situation, as health is the top priority. When driving in hot weather, I first turn on the recirculation mode for 10 minutes to cool down quickly, then steadily switch to fresh air mode to improve air circulation and prevent the accumulation of harmful gases like formaldehyde inside the car. The fresh air mode also helps prevent dizziness and fatigue, especially when traveling with family. Of course, keeping the fresh air mode on for a long time may consume a bit more fuel and slow down cooling, but I'd rather avoid health risks this way. Additionally, don't forget to ventilate the car before parking to prevent odors the next time you drive. Based on my experience, switching modes multiple times a day is the best way to balance comfort and health.
In summer, I prioritize fuel efficiency and environmental friendliness when using my car. Using the air conditioning in recirculation mode reduces engine load and cools the cabin faster, making it ideal for short trips. However, I briefly switch to fresh air mode for ventilation to avoid a stuffy feeling inside the car. In practice, I first close the windows and activate recirculation to quickly reach a comfortable temperature in hot weather, then switch to fresh air mode for a few minutes every half hour to maintain air freshness without wasting energy. Keeping the windows closed for extended periods can increase system load and actually consume more fuel. The key is to find the right balance by monitoring the AC's efficiency and preventing the car from turning into a steamer.
From a maintenance perspective, regarding summer air conditioning issues, starting with the recirculation mode provides the best cooling effect with lower system pressure. However, avoid exceeding 30 minutes to prevent air pollution from affecting the cabin air filter's lifespan. Then switch to fresh air mode to introduce outside air, which reduces condensation buildup and prevents odors or mold growth. For practical operation, it's recommended to change modes on flat road sections and minimize switch adjustments on bumpy roads. Remember to check your AC settings, as some vehicles can automatically switch modes, making it both convenient and beneficial for system maintenance.
