···
Log in / Register

What to Do When the Windshield Fogs Up with the AC On?

5 Answers
LeIsaac
07/23/25 6:33pm

Here are solutions to deal with windshield fogging when the AC is on: 1. Apply Anti-Fog Spray: Spray a small amount of anti-fog solution on the inner surface of the car windows to remove dirt and stains. While cleaning the glass, it forms a thin transparent protective film that effectively prevents moisture from condensing into fog, especially useful in cold winters. 2. Air Conditioning Cooling Method: Use the AC's cooling and dehumidifying function to reduce air humidity and eliminate fog. In summer, especially when many people enter the car without turning on the AC promptly, the exhaled humid air can quickly cause the windshield to fog up. 3. Air Conditioning Heating Method: Use the heating function to raise the temperature and remove fog. This can quickly prevent heavy fogging on the windshield, but the rear and side windows warm up more slowly, requiring more time to completely clear all fog.

Was this review help?
1
1
Share
McLillian
08/10/25 2:07pm

Oh, I've encountered this issue while driving - it's really annoying when the windows fog up with the AC on, mainly due to the temperature difference between the warm interior and cold exterior causing moisture condensation. My usual approach is to first press the defog button in the car, direct the vents to blast air at the windows, and turn on the external circulation mode to reduce humidity. I set the temperature around 22°C, avoiding extremes. Normally, I'm careful not to leave wet clothes in the car or bring wet umbrellas inside on rainy days to maintain dry air. Regularly cleaning the windshield of grease with tissues or specialized cleaners significantly reduces fogging chances. Don't neglect the AC filter either - a dirty one impairs dehumidification, so I recommend checking or replacing it every six months. Safety first: if fog obstructs visibility, don't force it; pull over immediately to address it and wait for the fog to clear before continuing. These tips have served me well for years and are quite effective.

Was this review help?
4
2
Share
Expand All
VanMason
09/22/25 8:53am

As a newbie, I also experienced fogging when turning on the AC right after buying my car, which was quite alarming. Later, I learned a thing or two: it's mostly caused by high humidity or dirty glass leading to condensation. The solution is simple—just press the defrost mode button and increase the fan speed to blow on the windshield. Avoid using recirculation mode; switch to fresh air intake to reduce moisture. Set the temperature to medium, as higher settings can worsen fogging. For daily prevention, I wipe the inside of the windows clean after washing the car to avoid residual water droplets. On humid days, turning on the AC a few minutes before driving helps a lot. If it rains or gets cold, keeping a towel handy to wipe the windows works too. These basic steps are easy to remember. New drivers shouldn’t panic—just spend two minutes adjusting the AC, and safe driving is what matters most.

Was this review help?
14
1
Share
Expand All
LePaige
11/06/25 3:13am

I have experience dealing with fogging when the AC is on: the temperature difference causes moisture to condense on the glass, affecting visibility. The key is to use the AC's dehumidification function. Immediately switch to defog mode, adjust the airflow to the windshield, and enable external circulation. Don’t set the temperature too low; around 25°C is ideal. Increase the fan speed to accelerate air circulation. For prevention, regularly clean the glass and AC air intake to reduce dust buildup. When parking, open the windows to let moisture escape. If fogging occurs, don’t panic—follow the steps above, and the fog will clear quickly. The focus is on maintaining a dry interior environment to ensure driving safety.

Was this review help?
19
2
Share
Expand All
ZaneDella
12/27/25 5:01am

I always try to save some fuel when driving. When it's foggy, I use the defogging mode but not by blasting the AC. Lowering the fan speed can also dehumidify, saving some energy. Turn on the AC's external circulation and set the temperature to 20 degrees to avoid excessive cooling. Regularly wipe the front windshield to prevent dust and grease buildup; check and clean the AC filter monthly to extend its lifespan and save money. Preheat the AC before heading out for more efficient dehumidification. Avoid placing water bottles or wet items in the car to reduce moisture sources. Simple maintenance like cleaning the wiper blades during car washes costs just a few dollars but prevents issues. If fogging occurs, don't panic—adjust the AC slowly to ensure safety.

Was this review help?
13
2
Share
Expand All
More Forum Discussions

Is the Vehicle and Vessel Tax Useful If the Car Is Flooded?

If a car is flooded, the Vehicle and Vessel Tax is not useful and cannot be claimed for compensation. Only if the vehicle is insured with Vehicle Damage Insurance will the insurance company provide compensation. Vehicle Damage Insurance, also known as Collision Coverage, compensates for the loss of the insured vehicle caused by natural disasters or accidents within the scope of insurance liability. Although the Vehicle and Vessel Tax cannot be claimed for compensation, it can be refunded. According to relevant regulations, for newly purchased vehicles or vessels, the taxable amount for the year of purchase is calculated monthly from the month when the tax obligation arises. The taxable amount is the annual taxable amount divided by 12 and then multiplied by the number of taxable months. Within a tax year, if a taxed vehicle or vessel is stolen, scrapped, or lost, the taxpayer can apply for a refund of the tax from the month of theft, scrapping, or loss to the end of the tax year by presenting the relevant certificate issued by the administrative authority and the tax payment receipt to the competent tax authority where the tax was paid. For example, if a car owner's Vehicle and Vessel Tax is due in December this year, but the vehicle is flooded and scrapped in July, after obtaining the scrapping certificate from the traffic management department, the owner can apply for a tax refund at the local tax office for the Vehicle and Vessel Tax from July to December.
20
3
Share

What material spark plug is used in the Volkswagen Lavida?

The Volkswagen Lavida uses nickel-plated copper spark plugs. Spark plugs, commonly known as fire nozzles, function by discharging the pulsed high-voltage electricity delivered by the high-voltage wire, breaking down the air between the two electrodes of the spark plug to generate an electric spark, thereby igniting the air-fuel mixture in the cylinder. Location of the spark plug: Spark plugs are installed on the side or top of the engine. In early designs, spark plugs were connected to the distributor via ignition wires. Over the past decade, most car engines have been updated to connect the ignition coil directly to the spark plug. Working principle of the spark plug: The ground electrode of the spark plug is connected to the metal shell, which is threaded into the engine block via the cylinder head. The insulator primarily serves to isolate the metal shell from the central electrode. The terminal nut is the part of the spark plug that contacts the high-voltage coil. When current passes through the terminal nut and the central electrode, it breaks down the medium between the central electrode and the ground electrode, generating a spark to ignite the air-fuel mixture in the cylinder. Effects of spark plug damage: If the spark plug is damaged, it can directly cause issues such as leakage in the vehicle's ignition system, increased fuel consumption, and reduced power. The most significant problem is difficulty in ignition, affecting the normal operation of the vehicle. Severe erosion of the spark plug, such as scarring at the top, damage, or melting and erosion of the electrodes, indicates that the spark plug is damaged and should be replaced.
19
4
Share

Why is the air conditioning not cooling even when the AC is turned on?

Here is an introduction to the car air conditioning AC button: 1. The AC button is the cooling switch for the car air conditioning. When pressed, the air conditioning compressor starts working, and the air blown out by the blower becomes cold. 2. For example, during hot summer days, to lower the temperature inside the car, press this button and turn the temperature selector switch to the blue part, and cold air will blow out. 3. If equipped with automatic air conditioning, simply press the AC button followed by the AUTO button. The automatic air conditioning will adjust the interior temperature based on the difference between the inside and outside temperatures.
18
4
Share

Is it normal for tire pressure to increase while driving?

This is a normal phenomenon. When the vehicle is in motion, friction between the tire surfaces and the road generates heat, causing the internal temperature of the tire to rise. As the gas inside expands, the tire pressure increases accordingly. What is the standard tire pressure: According to the international GBT2978-2008 standard, the recommended tire pressures for different types of tires are as follows: Standard tires: 2.4-2.5 bar; Reinforced tires: 2.8-2.9 bar; Maximum pressure: should not exceed 3.5 bar. Other related questions: Is a tire pressure of 2.0 bar normal? No, it is not normal. Per the GBT2978-2008 standard, the standard tire pressure for regular tires is 2.4-2.5 bar. A pressure of 2.0 bar is below the minimum recommended value, so it is not normal. What is the normal tire pressure in winter? — In winter, adjust the tire pressure slightly higher by about 0.2 bar based on the standard tire pressure. What is the normal tire pressure in summer? Generally, the lower limit of the standard tire pressure is sufficient. For example, the lower limit for standard tires is 2.4 bar. If the car is often parked outdoors, the tire pressure can be about 0.1 bar lower than the standard to prevent blowouts due to high temperatures.
18
0
Share

Can You Get a Driver's License with Blindness in One Eye?

Whether you can obtain a driver's license with blindness in the left eye depends on the condition of the right eye. According to the regulations issued in 2016, individuals with monocular vision impairment can apply for a motor vehicle driver's license for small cars or small automatic transmission vehicles if their right eye's naked or corrected vision reaches 5.0 or above on the logarithmic visual acuity chart, and their horizontal visual field reaches 150 degrees. It is necessary to first undergo a medical examination to check the condition of the right eye. Below are the requirements for obtaining a driver's license: Age requirements: Applicants for small cars or small automatic transmission vehicles must be at least 18 years old, while a truck driver's license requires the applicant to be at least 21 years old. Height requirements: For all vehicle types, the maximum age limit is 70 years old. The height requirement is at least 1.55 meters for large vehicles and at least 1.50 meters for cars. Certain medical conditions disqualify applicants: Individuals with organic heart disease, epilepsy, Ménière's disease, hysteria, dementia, or neurological diseases affecting limb movement are not eligible to obtain a driver's license. Traffic violations: Those whose driver's license was revoked due to traffic violations can reapply after 2 years. Those whose license was revoked due to causing a traffic accident can reapply after 3 years. Those whose license was revoked due to drunk driving can reapply after 5 years.
8
1
Share

What engine is used in the Fengxing S500?

The Fengxing S500 is equipped with a 1.5L naturally aspirated engine across the entire lineup. Here are the details about this engine: 1. The 1.5L naturally aspirated engine in the Fengxing S500 delivers 120 horsepower and a maximum torque of 143 N·m, with the maximum power achieved at 6000 rpm and the maximum torque at 4000 rpm. 2. This engine features MIVEC technology and multi-point fuel injection, and it uses an aluminum alloy cylinder head and block. It is paired with a 5-speed manual transmission. 3. The front suspension of the Fengxing S500 uses a MacPherson independent suspension, while the rear suspension employs a trailing arm non-independent suspension.
14
5
Share
Cookie
Cookie Settings
© 2025 Servanan International Pte. Ltd.