How a Car AC System Works - For Beginners

Summary

In this video, the speaker explains how a car's air conditioning (AC) system works, focusing on key components like the compressor, condenser, receiver dryer, and evaporator. He describes how refrigerant flows through the system, cycling between gas and liquid states to cool the cabin air. The video also provides practical advice on diagnosing AC issues, such as refrigerant leaks, and offers guidance on topping off refrigerant or finding leaks. With clear explanations and car-specific examples, viewers will gain a deeper understanding of their AC system and how to maintain it.

Takeaways

• 😀 The car's AC system is a closed system, which should not be exposed to atmospheric pressure. Leaks can cause refrigerant loss, disabling the AC compressor.
• 😀 To maintain your car's AC, you can top off refrigerant using a safe method as demonstrated in another video, especially if low refrigerant is the issue.
• 😀 Finding leaks in the AC system can be done using a simple and practical sulfur method, as covered in another video.
• 😀 The AC system works by cycling refrigerant between a gas and liquid state, using the temperature difference to cool the air inside the cabin.
• 😀 The AC compressor compresses refrigerant, turning it into a gas that flows to the condenser, which cools it back into a liquid state.
• 😀 High-pressure refrigerant travels through the system (marked in red), and low-pressure refrigerant travels in the opposite direction (marked in blue).
• 😀 The AC condenser is located in front of the radiator, and a fan blows air to cool the refrigerant, converting it from gas to liquid.
• 😀 A receiver dryer removes contaminants and moisture from the system, which is essential for maintaining system efficiency and preventing damage.
• 😀 The refrigerant then passes through either an expansion valve or orifice tube, reducing its pressure and temperature as it moves to the evaporator.
• 😀 The evaporator, located inside the car's cabin, absorbs heat from the air, which cools down the air blown into the cabin by the AC blower fan.
• 😀 If your car uses an orifice tube, the system will have an AC accumulator instead of a receiver dryer, but they serve similar functions in managing moisture and contaminants.

Q & A

What does it mean that the AC system is a closed system?

A closed system means that the AC system is not supposed to be exposed to atmospheric pressure. It should always remain sealed to prevent refrigerant loss, ensuring the system functions properly.

What happens when there is a refrigerant leak in the AC system?

When there is a refrigerant leak, it opens the system to atmospheric pressure, causing the refrigerant to escape. This loss of refrigerant disables the AC compressor, which stops the system from cooling the car’s cabin.

What is the purpose of the AC compressor in the system?

The AC compressor's role is to compress the refrigerant, turning it into a high-pressure gas, which is then pushed out of the compressor and sent to the condenser.

Where is the AC condenser located in most cars?

The AC condenser is typically located in front of the car's radiator. It looks like a smaller version of the radiator and cools down the high-pressure refrigerant gas coming from the compressor.

How does the AC fan help cool the refrigerant in the condenser?

The AC fan blows air over the condenser, which helps dissipate heat and cool down the refrigerant, turning it from a gas into a liquid.

What is the difference between the high-pressure and low-pressure sides of the AC system?

The high-pressure side (marked in red) is where the refrigerant is in a gas state under high pressure, while the low-pressure side (marked in blue) is where the refrigerant expands and cools, becoming a low-pressure gas.

What does the receiver dryer do in the AC system?

The receiver dryer removes moisture and contaminants from the refrigerant, preventing damage to the AC system and ensuring it functions efficiently.

What is the role of the expansion valve or orifice tube?

The expansion valve or orifice tube reduces the pressure of the liquid refrigerant, allowing it to expand into a gas. This expansion cools the refrigerant, which is essential for cooling the air inside the car.

How does the evaporator contribute to the cooling process?

The evaporator absorbs heat from the air blowing over it, cooling down the air that is then blown into the car’s cabin by the AC blower fan.

What should you do if you ever repair your AC system?

If you repair your AC system, you must replace the receiver dryer or AC accumulator (depending on your system type) to avoid contamination and ensure the system operates properly.