A modern car has become comfortable thanks to the painstaking work of engineers and designers, as well as the development of technology. One of the brightest representatives of a pleasant microclimate in the cabin is air conditioning. Today, most car manufacturers install this unit during the assembly process of the car, and in some cases, car owners are the initiators of the installation of climate control equipment. In either case, it is connected to the vehicle's life support system and has a similar design. Its operation depends on many factors, including how often the motorist refills freon, inspects the system for damage, carries out repairs, and also monitors the condition of such important parts as the car AC compressor.
As you know, the car AC compressor is the main element of the system. If we draw analogies with the human body, the compressor is the heart of the system. A similar comparison suggests itself if we consider the principle of operation of this unit, which we will talk about today. We will also tell you about the types of this element and describe in detail the most common cases indicating the incorrect operation of this component.
Types of AC compressors for a car
There are various kinds of compressors in modern car air conditioning systems that are differing, for example, in power, performance, noise, etc. In general, we will consider some models of structures using the example of the DENSO compressor range.
- The most popular type of compressor is a swashplate. The drum of the unit, containing several pistons (from five to seven), is driven by the engine of the car. The pistons circulate the refrigerant sliding relative to the stationary wobble plate. The volume of the pumped-over coolant can be changed due to the variable angle of inclination of the disc. DENSO compressors of this type (SE, SB, SL) are equipped with many large vehicles for which high performance of the AC system is important.
- Compressors with wobble plate, DENSO CA. In this design, on the other hand, the swashplate is movable, and the pistons and drum do not rotate. The distribution system in these compressors is a little more complicated, and today they are gradually losing ground.
- Scroll compressors are completely different types of AC compressors for a car. Their mechanism consists of two spirals: movable and fixed. Compressors of the DENSO SC type are renowned for their extremely low noise levels. Scroll compressors take up very little power from the engine and are therefore excellent for air conditioning systems in cars with small light engines. Due to its low energy consumption, DENSO ES compressors with an electric drive are also equipped with a scroll mechanism. The advantage of these compressors is the ability to operate on the vehicle's battery, that is, with the engine off, which is important for hybrid vehicles.
- Finally, rotary vane compressors, DENSO TV. These compressors are designed for low power systems. Their principle of operation is familiar to many motorists from booster pumps it is an eccentric in a chamber of variable volume, equipped with movable blades. The simplicity of the design of these compressors ensures their reliability and ease of maintenance.
Working principle for AC car compressor
In a closed AC system, the cooling of freon in the evaporator occurs due to a sharp change in pressure: liquid freon under high pressure passes through a narrow opening, atomizing and instantly cooling. The task of the compressor is to pump refrigerant (freon) from the low-pressure circuit (from the condenser radiator) to the high-pressure circuit (to the evaporator radiator) with its simultaneous compression, which means an increase in temperature. In the condenser, the freon is cooled and turns into a liquid state, after which it enters the condenser again. The AC compressor is sometimes referred to as the "heart" of the system, so its smooth operation is so important for the normal operation of the air conditioner. At the same time, the compressor is also heavily loaded.
Mistakes of car AC compressor usage
Car owners who have not yet encountered air conditioner repair do not even know how expensive this procedure can be. That is why we immediately want to focus on the main errors that cause many problems in the operation of the car AC compressor.
- Ignoring the procedure for annual maintenance of the AC system. This is a mistake since a Freon leakage tolerance of up to 10% is provided for all rubber hoses due to their porosity. Therefore, it is easy to calculate the possible annual loss of freon in the car's air conditioner. Each vehicle with air conditioning in the engine compartment contains a plate indicating the type of freon and its amount in the vehicle system. If this is, for example, 525 g, then annual leaks can be up to 50 g. That is, if the air conditioner has not been refilled for four years, about 300 g of refrigerant may remain there. This is dangerous since the cooling efficiency deteriorates, the system operates under greater load, less lubricant circulates in it.
- Not turning on the air conditioner for preventive purposes in the winter. This procedure is necessary since, during the air conditioner's operation, all the insides of the air conditioning system are lubricated. This eliminates the drying out of rubber seals, hoses, etc., which allows you to maintain the tightness of the system, minimize refrigerant leakage, as well as lubricate all internal parts of the compressor and prevent corrosion. In winter, you can turn on the air conditioner in frosty conditions only in a warm room, since it will not work at subzero temperatures outside. A warm room for a car can be a service station, some car washes, covered parking. This operation takes 15 minutes for the air conditioning system.
- Installing a fine-grained mesh in front of the radiator-condenser, which impairs the cooling of the radiator. At the same time, the AC system's efficiency decreases, and the car compressor begins to work at a high load. Because of this, naturally, the resource of the compressor and many elements of the AC system is reduced. Similar problems arise in cases where the radiator-condenser is not cleaned of debris, especially after spring, when it gets clogged with fluff.
- Inadequate maintenance of air conditioners on the principle of "if only cheaper", but not by professionals at proven or recommended specialized service stations. But the latter has special equipment, including filling stations and gas analyzers for determining the composition of freon. During maintenance, there can be many violations that will disable the air conditioner. For example, you have been filled with low-quality freon, which includes its different types. Although this mixture as a whole may meet the temperature requirements (boiling or condensation point) of the same R134a freon, it may not be compatible with the oil used in the system. As a result, the system's lubrication will deteriorate significantly, and the car AC compressor will quickly fail.
We hope that our article helped you understand how the car AC compressor works and why you need it. Remember to exclude typical mistakes leading to the failure of this vital element. In case of problems and malfunctions, go to our store, we are sure that you will find all the necessary parts for it at competitive prices.
A short guide about AC compressor for car FAQ
- How long should a car AC compressor last?
Theoretically, the AC compressor for a car has ten years of operation, but in practice, wear occurs quicker not because the time has come but because of a system problem. If you do not monitor the tubes and hoses, as well as the bearings of the clutch and pulley, then within three years, the system may become unusable.
- What are the symptoms of a bad AC compressor?
Typical signs of an AC compressor malfunction: a constant hum, which is heard even when the air conditioner is turned off, a rumble, or a sound that appears when turned on; there is no click when turned on (the electromagnet does not work).
- Can AC compressor be repaired?
It is necessary not only to eliminate the leak and fill in new refrigerant but also to thoroughly flush the system and sometimes even replace the pistons to restore the operation of the AC compressor for a car. This is an extremely expensive repair, which does not always make sense since installing a new compressor will be easier and cheaper.
- Where to buy an AC compressor for a car?
You can buy an AC compressor for a car on PartSouq. Here you will find a pleasant service with affordable prices and fast delivery.