···
Log in / Register

What are the differences between vehicle air recirculation and fresh air mode?

5 Answers
MargaretFitz
07/28/25 10:24pm

The differences between vehicle air recirculation and fresh air mode are as follows: 1. Different working principles: Recirculation means the air inside the vehicle is heated or cooled and then recirculated back into the cabin; Fresh air mode draws outside air into the vehicle after heating or cooling it, achieving air exchange between the interior and exterior. 2. Different usage methods: When initially turning on AC cooling or heating, you can first activate recirculation to quickly lower or raise the cabin temperature; After temperature stabilizes, appropriately switch to fresh air mode for ventilation; Avoid using fresh air mode when outside air quality is poor, such as in heavy traffic with exhaust fumes or poorly ventilated underground parking. When driving on highways, never open windows - simply use fresh air mode instead. When outside air is clean but the cabin feels stuffy, promptly switch to fresh air mode for ventilation.

Was this review help?
1
2
Share
MacJohnny
08/12/25 1:50am

The difference between the car's internal and external air circulation is simply the source of air. Having driven for years, I know that internal circulation recirculates the air inside the car. It's usually activated by pressing a button and is ideal for quick cooling or heating, like turning on the AC in summer and switching to internal circulation to prevent hot air from entering. External circulation draws in outside air, which is great for fresh air or defogging, such as using it on highways to avoid wind noise from open windows. I usually switch based on the situation: in city traffic jams, I use internal circulation to reduce exhaust fumes and prevent dizziness; in open outdoor areas, I switch to external circulation for fresh air. However, prolonged use of internal circulation can make the air stuffy and increase CO2 levels in the car, affecting concentration. That's why the car's AC system is well-designed and practical.

Was this review help?
18
4
Share
Expand All
BrookeLee
10/01/25 3:56am

The difference between the vehicle's internal and external air circulation is quite obvious. Having driven for decades, I can say that internal circulation keeps the air inside the car flowing in a loop without drawing in fresh air from outside. It's typically used when the air conditioning is on to quickly cool down or warm up the cabin. For example, in winter, turning on the heater with internal circulation warms up the car faster, but don't use it continuously as it can lead to poor air circulation and mold growth. External circulation, on the other hand, brings in outside air, which is beneficial for health. During long drives, switching to external circulation allows you to inhale fresh oxygen, reducing fatigue, and it also effectively clears fog from the windshield. I recommend using external circulation more frequently on highways or rural roads to ensure regular air exchange. In urban areas with frequent traffic lights, minimize external circulation to reduce exhaust fumes. Regularly cleaning the air conditioning filter is also crucial to prevent airflow blockage. This design is quite user-friendly.

Was this review help?
15
3
Share
Expand All
MacEmilio
11/14/25 5:44am

The difference between the vehicle's internal and external air circulation lies in the airflow path. As an automotive enthusiast, I know that internal circulation closes the external air intake, only recirculating the air inside the car, similar to closing all windows and doors while running a fan. External circulation opens the air intake, drawing in outside air, like cracking a window for ventilation. The air conditioning system uses computer-controlled dampers to achieve this. It's very user-friendly: internal circulation saves energy and cools faster when cooling is needed; during external circulation, if air quality is poor, sensors automatically adjust the fan speed. I've also installed a high-efficiency filter to enhance air purification. From my experience, internal circulation is ideal for rainy or smoggy days, while switching to external circulation on sunny highways provides a refreshing experience. The overall design ensures a comfortable driving experience.

Was this review help?
17
2
Share
Expand All
Sean
01/04/26 7:25am

The vehicle's internal and external air circulation systems have fundamental differences. As I have children at home, I understand that internal circulation means the air inside the car recirculates without allowing outside air to enter. This is most suitable for use in heavily polluted areas or when maintaining cool/warm temperatures inside the vehicle - for example, using internal circulation with AC in summer saves energy and keeps things cool, though prolonged use may cause stuffiness. External circulation introduces outside air, improving oxygen levels in the cabin. It's particularly effective for defogging in winter and reduces allergen entry (helpful for pollen allergy sufferers). For safety, I regularly check air ducts and filters during maintenance to prevent bacterial buildup. During rainy days, I use internal circulation to reduce condensation, while switching to external circulation in good weather ensures my family breathes comfortably. These small details are crucial.

Was this review help?
19
3
Share
Expand All
More Forum Discussions

How Fast is 25km/h?

In everyday language, the term 'speed in code' originates from the speed unit 'mile'. The commonly mentioned speed of 100 code is equivalent to 100 kilometers per hour, while the British term '100 miles' equals 160 kilometers per hour. Therefore, 25km/h represents 25 miles, whereas in foreign countries it is 40 miles, which is approximately a speed of 7 meters per second. Relevant information about speed limits is as follows: 1. Introduction to Speed Limits: Speed limits usually refer to the regulation of vehicle speeds within a certain numerical range over a specific length of road. 2. Purpose of Speed Limits: The main purpose is to pre-warn drivers to reasonably control their speed in subsequent road sections ahead, prevent the dangers of speeding, and ensure driving safety. Speed limits are an indispensable and also the most important part of road transport safety.
14
3
Share

What are the benefits of having larger front wheels and smaller rear wheels?

Front wheels are responsible for steering, and smaller wheels have less friction, which has less impact on speed. Rear wheels rely on friction to drive the vehicle, so the rear wheels are slightly larger. Having smaller front wheels and larger rear wheels provides better climbing power, higher safety performance, and lighter steering for easier turning. Here is additional information: Rear wheels: Rear wheels are the driving wheels, while front wheels are the steering wheels. Besides steering, the front wheels only need to bear the weight of the diesel engine, with essentially no other tasks, so there is no need for them to be very large. On the other hand, rear wheels are the driving wheels. For example, tractors are characterized by strong towing capacity. Diesel engines inherently have high torque, and with the addition of high and low speeds in the transmission, the torque amplification in low gear is quite powerful, allowing the vehicle to easily pull several tons of cargo.
12
0
Share

What are the effects of removing the thermostat in summer?

Car thermostats should not be removed, otherwise the engine will have difficulty maintaining a normal operating temperature, which not only affects the engine's working condition but also reduces the car's power. The effects of removing the thermostat are as follows: 1. Lower temperature: After removing the thermostat, the engine's operating temperature will definitely be lower than before, affecting the engine's thermal efficiency and leading to issues such as insufficient power. 2. Increased warm-up time: Secondly, the engine's warm-up time will be several times longer than normal, and the internal parts' wear may even increase by several dozen times. 3. Poor fuel atomization: Due to the engine's operating temperature being too low, fuel atomization will be poor, and over time, a thick layer of carbon deposits can easily form, which is very detrimental to the car's fuel consumption.
9
3
Share

Where is the thermostat located on the Vios?

Toyota Vios thermostat is located on the lower radiator hose, to the right of the exhaust manifold. Here is more information about the thermostat: 1. Introduction: The thermostat automatically adjusts the amount of water entering the radiator based on the coolant temperature, changing the water circulation range to regulate the cooling system's heat dissipation capacity, ensuring the engine operates within an appropriate temperature range. 2. Working principle: Automobiles typically use a wax-type thermostat. When the coolant temperature is below the specified value, the refined paraffin inside the thermostat's temperature-sensing element remains in a solid state, and the thermostat valve closes the passage between the engine and the radiator under the action of the spring. The coolant returns to the engine via the water pump, performing a small circulation within the engine.
8
2
Share

How Long Does Audi Personalization Customization Take?

Audi personalization customization takes at least 5 months. Here is a brief introduction about Audi: 1. Basic Information: Audi is a famous automobile developer and manufacturer, with its logo being four interlocking rings. It is currently a subsidiary of Volkswagen Group, headquartered in Ingolstadt, Germany. Main models include Audi A1, Audi A3, Audi A4, Audi A5, Audi A6, Audi A7, Audi A8, Audi Q1, Audi Q2, Audi Q3, Audi Q5, Audi Q7, Audi Q8, Audi TT, Audi R8, as well as S and RS performance series. 2. Company Address: The Audi Group includes its parent company and subsidiaries such as Audi Hungaria, quattro GmbH, Lamborghini Automobili, and Cosworth Technology, Audi Brasil and Audi Senna. Additionally, Audi also has production plants in China, Malaysia, South Africa, and other locations.
4
5
Share

What colors are available for the Beijing BJ40?

Beijing BJ40 offers 7 color options: Extreme Night Black, Jungle Green, Flame Red, Snowfield White, Desert Gold, Danxia Red, and Beret Green. Here is more information about the Beijing BJ40: 1. Vehicle Positioning: The Beijing BJ40 is manufactured by Beijing Off-Road and is classified as a compact SUV. The vehicle dimensions are 4630mm in length, 1925mm in width, and 1871mm in height, with a wheelbase of 2745mm. It is a 5-door, 5-seater SUV. 2. Powertrain: The Beijing BJ40 is equipped with a 2.0T turbocharged engine, delivering a maximum power of 170.0 KW, 231 PS, and a peak torque of 380.0 Nm.
12
2
Share
Cookie
Cookie Settings
© 2025 Servanan International Pte. Ltd.