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Basic Understanding of a Automotive AC compressor

Basic Understanding of a Automotive AC compressor

What Does an Air Compressor in a Car Do?

Air compressors have made life easier for people on countless fronts since the early days of automotive assembly. One of the greatest innovations was Air Conditioning, which made life easier for people in the humid depths of summer months.

A/C systems were soon incorporated into automobiles, which allowed families to commute and embark on vacations in greater comfort because temperatures inside of passenger compartments could now be lowered by at least 20° from the outdoor weather. So what does a car’s air compressor do? The air compressor makes the whole A/C process possible in vehicles.


How Does the Air Compressor Cool Your Car?

When the temperatures start to rise along the highways and congested roads, there’s nothing more refreshing than the cool blast of air conditioning from the vents of a car, truck or van. In the heat of 85°-plus temperatures, that icy A/C breeze can feel like the ultimate relief from the virtual oven outside.

Despite the cool feeling, however, there’s no actual ice involved in the A/C process. Those icy gusts you’re experiencing are actually the result of hot gases being removed from the humid air. It’s a multi-step, thermodynamic process that’s all made possible by the power of air compression.

Whether you’re the driver or a passenger, you take control of the car’s air compressor the moment you push the A/C button. By doing so, you’ve activated the compressor to compress and hike the temperature of the refrigerant. After activation, the refrigerant is then sent through the condenser, where the heat is lost. Next, the refrigerant goes through the dryer and is purified of contaminants. Once purified, the refrigerant is stripped of its pressure after it passes through the expansion valve. The final step is traveling through the evaporator inside the dashboard, and the refrigerant is rendered super cold and moisture free. The gusts of cold air you feel are the result of the motor’s blower pumping air through this newly cold refrigerant and out through the blowers.

Basic Understanding of a Automotive AC compressor


How Long Do A/C Air Compressors Last?

To the vast majority of drivers, the functions that take place under the hood of a car are seldom considered — unless a strange sound is heard or a warning light flashes. As a function of vehicles that’s used primarily during warmer months, the air conditioning compressor doesn’t quite face the same amount of year-round wear and tear as the brakes and clutch, but it does have its share of vulnerabilities. After all, it’s the drive belt of the engine that sets the whole A/C process into motion.

While it’s hard to determine the amount of time a given car part will function to its maximum abilities, certain factors might indicate the likely lifespan of an A/C air compressor. The foremost factor is the vehicle’s age. While new vehicles tend to be equipped with more durable compressors, the toll of mileage can affect any of the internal parts. If the compressor bears repeated undue stress over time, it could slowly lose its ability to send cool air into the passenger compartment.

While the A/C compressor can benefit from the relative lack of wear during winter months, it can also stagnate if left to hibernate during this time. Therefore, it’s best to activate the A/C for at least 10 minutes every 30 days between November and February to ensure it doesn’t take a permanent rest. Granted, the functions in question here are not limited to the A/C in all vehicles. In some cars, the compressor is also utilized to offer heat and ventilation, both of which tend to be used primarily between late fall and early spring.

How Often Should an A/C Air Compressor Undergo Maintenance?

The litmus test for a working A/C system is whether or not it keeps you and your passengers sufficiently cool when it’s hot outside. If a few minutes of breeze actually makes your car feel too cold — despite temperatures of 95° or more outside — then your A/C isn’t due for maintenance and probably won’t be for the foreseeable future. As the saying goes, if it isn’t broken, don’t fix it — the money can be saved or allocated to other areas of car repair.

So when should you take your vehicle in for A/C maintenance? If coldness is either slight or nonexistent in the air coming through the vents, it’s likely due to problems with the system. Depending on the extent of the problem, you’ll either need a recharge or an outright replacement of the A/C air compressor. For most cars, a recharge is needed every few years, but replacements can be avoided for the average span of ownership of most vehicles as long as due care is taken for the A/C system.

In any case, when your vehicle’s A/C starts to lag, it’s time for an inspection. Considering the high-pressure functions that a compressor must perform in order to provide cooled air, the circuitry is complex and maintenance is usually best performed by skilled technicians.

What Is the Key Fluid in an A/C System?

If your A/C fails to deliver the coolness levels you’ve come to expect, it’s likely down to a low supply of refrigerant — the fluid that makes cold air from hot air. What exactly are the elements that comprise this fluid? For that, a bit of history is in order.

Traditionally referred to by the antiquated DuPont trademark Freon, refrigerant comes in three forms that have appeared in succession since the dawn of air conditioning: R-12, R-134A and HFO-1234yf. Much like oil and antifreeze, refrigerant is one of the fluids that facilitates a vital function in most vehicles.

Technically, the only actual Freon was R-11, which was one of the most common chlorofluorocarbon (CFM) fluids in use up until 1996, when CFM was banned in the United States due to its impact on the ozone. Subsequently, automakers replaced R-11 with the non-CFM fluid R-134A, which scientists developed as a somewhat eco-friendlier though still chemically-laden refrigerant. In 2013, however, the auto industry initiated another change, this time to HFO-1234yf, which is believed to be the most environmentally sound refrigerant yet conceived. With this latest development, cars pose a smaller environmental threat in cases where the refrigerant leaks.


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