The ultimate guide to choosing the air conditioning compressor

What is an air conditioning compressor?

The Air Conditioning Compressor serves as the central component of a vehicle's air conditioning system. It functions akin to a pump, where it takes refrigerant and pressurises it, subsequently directing it towards the evaporator. The compressor's clutch is activated by a drive or serpentine belt, engaging the compressor into operation when the air conditioning is switched on. This pivotal mechanism plays a crucial role in maintaining the optimal functioning of the vehicle's cooling system.

How does the air conditioning compressor in my vehicle work?

The air conditioning system in a vehicle does not actually generate cold air; rather, it functions by extracting heat and moisture from the air inside or outside the car, resulting in cooler air being circulated. Understanding the workings of the various components of the system is crucial in comprehending the repair processes involved in maintaining the air conditioning system.

Within the AC system, the refrigerant, commonly known as freon, plays a vital role. The AC compressor plays a key role in the high-pressure side of the system, where it compresses the freon into a high-pressure state, causing it to liquefy. This pressurised freon then moves through the high-pressure lines to the condenser. The condenser, akin to a miniature radiator, exposes the liquid freon to external air, facilitating the transfer of heat from the liquid to the surrounding air. Subsequently, the liquefied freon passes through the expansion valve or orifice tube, where it undergoes a restriction process and transforms into a gaseous state within the low-pressure side of the AC system.

Upon exiting the expansion valve, the gaseous freon then enters the receiver dryer or accumulator, which houses a desiccant bag designed to eliminate and accumulate unwanted moisture, water, and impurities. The purified gaseous freon proceeds through the tubing into the evaporator, typically situated within the passenger compartment of the dashboard. In its gaseous state, the freon can absorb heat from the air flowing through the evaporator fins, resulting in the generation of cooler air. Fans within the system then circulate this cooler, dehumidified air into the car's cabin.

The refrigerant, now carrying the absorbed heat, returns to the compressor through the suction hose of the AC system, where it is compressed back into a high-pressure gas, ready to initiate the entire cooling cycle once more. This elaborate process ensures the efficient functioning of the air conditioning system in vehicles, providing occupants with a comfortable and controlled interior climate.

 

How to choose the right air conditioning compressor?

When embarking on the journey of purchasing the appropriate AC compressor for your vehicle, it is imperative to possess specific information regarding your vehicle. The primary piece of information required is the precise year, make, and model of your vehicle, and potentially even your sub-model. This information holds significant importance as manufacturers alter various parts for different model years and at times even within the same model year, contingent upon trim levels, engine choices, and other factors. Consequently, you may also need to have access to your vehicle's production date, which denotes the exact date of its manufacture in the factory. The production date can typically be located inside your vehicle on the driver's side door jam, usually documented in a month/year or date/month/year format. Although most AC compressors featured on our platform do not necessitate the production date, should it be required, you can easily retrieve this information from your vehicle.

In instances where uncertainty surrounds the year, make, and model of your vehicle, or the production date is unknown, we can assist you in obtaining the precise replacement for your AC compressor by acquiring the manufacturer's part number directly from the component. Often, the part number is engraved on the compressor itself or is present on a sticker or label. However, with the passage of time, these part numbers may fade or become illegible. Should you lack access to these part numbers, we recommend reaching out to your vehicle manufacturer's local dealership and courteously requesting the OEM (original equipment manufacturer) part number of the AC compressor in your vehicle from their parts department. Simply provide them with your VIN number, and they will be able to retrieve this information for you.

Certain older vehicles were not originally equipped with air conditioning units from the factory. If this pertains to your vehicle, we advise consulting with an automotive air conditioning technician regarding the integration of an AC system into your car. To optimise cost-efficiency for this project, have the technician furnish you with the specific OEM part numbers of the required components and consider purchasing them online from our platform.

 

What are the symptoms of a bad AC Compressor?

Air conditioning compressors are subjected to significant stress due to the frequent activation and deactivation of the car's air conditioning system. This constant power fluctuation places a considerable strain on the compressor, clutch, and other internal components. Over time, this stress can lead to the deterioration of the compressor, ultimately resulting in failure. To identify potential issues with your AC compressor, it is crucial to be aware of warning signs that may indicate a problem. Here are the top four symptoms to watch out for:

Unusual Noises: When you start your air conditioner and notice unusual sounds emanating from the system, it is a strong indication that your AC compressor may be failing. The compressor relies on a sealed bearing and various internal components to function smoothly. If these bearings or components become damaged or worn out, the compressor's operation can be compromised, leading to increased noise levels. Unusual noises should not be ignored, as they often signify underlying issues that require prompt attention. Recognising this symptom early on can help prevent further damage and the need for compressor replacement.

Hot Air: If you find that your air conditioner is only blowing hot air instead of the cool air you desire, it is a strong indication that your AC compressor is malfunctioning. When the compressor is faulty, the refrigerant is unable to flow properly through the air conditioning system, leading to the absence of cool air. Initially, you may notice a gradual shift from cool air to slightly warmer air. Over time, the air will reach a stage where it is entirely hot, devoid of any cooling effect. This progression suggests a deteriorating compressor that requires attention to restore the functionality of your air conditioning system.

Leaking Fluid: The AC compressor is equipped with internal bearings that play a crucial role in preventing fluid leakage while the unit pressurises the refrigerant. Should these bearings deteriorate or sustain damage, the risk of fluid seepage increases significantly. In such instances, it becomes necessary to replace the bearings, as they are not repairable. It is imperative to address this issue promptly to ensure the optimal functioning of the AC compressor and the overall efficiency of the system.

The Clutch is Stuck: In the scenario where the clutch of the AC compressor becomes stuck or seizes, it impedes the transfer of power from the engine to the compressor. This connection is crucial for the compressor to utilise the engine's power effectively. Regrettably, in such situations, attempting to repair the clutch is often unfeasible. The most viable course of action typically involves replacing the entire compressor unit. This ensures the restoration of optimal functionality and efficiency to the air conditioning system.

 

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