What pressure does the freon cylinder hold?

The air conditioning system has become an integral part of any modern car. It allows you to maintain the optimal temperature in the car interior, regardless of external temperature fluctuations. The uninterrupted operation of the presented system largely depends on maintaining the established parameters under various operating conditions. One of these parameters is refrigerant pressure. If the presented value does not correspond to the declared value, the system ceases to function normally.

In order to prevent or at least reduce the risk of emergency situations, it is necessary to carry out regular maintenance, including a number of preventive measures.

It often happens that the driver, due to his ignorance, is not able to perform this kind of action. To do this, you need to master at least a minimum set of skills and abilities, as well as understand the principle of operation of the system as a whole.

Basics of car air conditioning

In order to take active steps to diagnose or eliminate an air conditioner malfunction, it is important to understand the basic principles of operation of this system.

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Referring to various competent sources, we can say that the presented systems were installed on cars at the beginning of the last century. Of course, over time, technological progress has made it possible to significantly improve such climate control systems. High-tech technologies have helped make systems more compact and energy-intensive, but their operation is based on almost the same principles.

The presented climate system is completely sealed. It consists of two circuits in which one can observe the transition of the working substance - freon - from one chemical state to another. In one of the circuits there is an area of ​​low pressure, in the other of high pressure.

The compressor is located at the boundary of these two zones. Figuratively speaking, it can be called the heart of the system, which ensures the circulation of refrigerant within a closed circuit. But “you can’t go far” with just one compressor. Let's start in order, from the moment the climate control button is turned on.

When the air conditioning system is turned on, the electromagnetic clutch of the compressor drive is activated. The torque from the internal combustion engine is transmitted to the compressor. He, in turn, begins to suck in freon from the low pressure area and pumps it into the high pressure line. As the pressure increases, the refrigerant gas begins to noticeably heat up. Moving further along the line, the heated gas enters the so-called condenser. This unit has much in common with the radiator of the cooling system.

How to check the pressure level yourself

There are often cases when, during the operation of a car’s split system, it becomes necessary to carry out a control measurement of pressure in the system circuits. You can successfully cope with this, at first glance, difficult task on your own, without the involvement of specialists and so-called servicemen.

All you need for this is a couple of pressure gauges with suitable connectors. To simplify the procedure, you can use a special pressure gauge unit, which can be purchased at many auto stores.

When carrying out the procedure for measuring the pressure of the air conditioning system, it is important to follow a certain sequence of actions:

• remove the plug from the system line;
• screw on the pressure gauge station, avoiding dust particles and debris getting into the system;
• start the engine and check performance indicators.

Depending on the ambient temperature and refrigerant labeling, the operating pressure for each circuit will vary.

For example, for freon R134a, at a temperature from +18 to +22 degrees, the optimal pressure value is:

• in the low pressure circuit - from 1.8 to 2.8 kg/cm2;
• in the high pressure circuit - from 9.5 to 11 kg/cm2.

For a more detailed analysis of the presented indicators, you can use summary tables available on the Internet.

By comparing the obtained data with the established values, you can verify that there is insufficient or excess pressure in the air conditioning system.

Based on the results of the test, certain conclusions can be drawn about the serviceability of a particular system component. It is worth noting that the identified parameters in no way indicate an insufficient amount of refrigerant in the system. To do this, you need to measure the temperature of the working fluid.

Check video

We bring to your attention video material dedicated to diagnosing air conditioner malfunctions based on readings from the pressure gauge unit.

The surest way to charge a car air conditioner is to charge it by weight. Gas stations and electronic scales with a refueling function are designed for this purpose. At home, it is unlikely that correct refueling is possible, however, data on the standards for refueling car air conditioners may be of interest to car owners.

What pressure should it be and how to refill the air conditioner after checking

The pressure in the various circuits of the system depends on a number of factors. As noted earlier, this indicator is largely influenced by air temperature and the type of working fluid.

One way or another, for the most part, modern air conditioning systems are usually charged with universal types of refrigerants that have similar operating parameters. The most common of them is the so-called 134 freon.

So, in warm weather, this type of refrigerant should be in the air conditioning system under pressure equal to:

• 12 – 15 kg/cm2 in the high pressure circuit;
• 1.5 – 5 kg/cm2 in the low pressure circuit.

It must be remembered that this is one of the key performance characteristics of car climate systems. It allows you to judge the serviceability of its working units and elements.

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The procedure for measuring air conditioner pressure often leads to loss of refrigerant. In this regard, there is a need to replenish the system to the required value.

To refuel the system, you should have some equipment with you. The list of equipment includes:

• manometric block;
• a pair of hoses for air conditioning;
• reservoir with working fluid;
• transition fittings with shut-off valves.

Even a novice car enthusiast can cope with refueling the system with freon; you just have to follow the step-by-step instructions:

• screw the fitting with the tap to the freon tank;
• connect the fitting to the hose;
• connect the other end of the hose to the pressure gauge station;
• mount the remaining hose with fitting on another outlet of the pressure gauge block;
• proceed directly to refueling the system by opening the tap.

To clarify the filling capacity of the air conditioning system of a particular car, just look at the information plate under the hood of your car. After studying it, you will find out the type/brand of working fluid and the volume of the system.

Main technical parameters of freon R507

The peculiarity of an azeotropic mixture is that its properties are identical to those of single-component substances. For this reason, R507 freon is charged into the refrigeration system as a one-component composition in liquid or vapor state. After eliminating the place of depressurization and leakage in the pipeline, refueling can be carried out with a mixture in the vapor state or in the form of a liquid.

Technical characteristics of freon R507:

For safe operation of the compressor, the manufacturer recommends adding polyester oils to the system with circulating freon 507: Mobil, Planetelf ACD, Suniso, Bitzer.