What kind of refrigerant does a car ac need?

Freon is an excellent refrigerant used in car air conditioning systems. Unlike household refrigerators, car air conditioners are connected by additional rubber wires. There is no guarantee that the refrigerant could not leak – it starts to evaporate slowly even through the smallest cracks in the seals. For this reason, car air conditioners must be supplied regularly.

What should we know about freon?

Studies have shown that a person can feel good at temperatures of 20-27 degrees Celsius (68-80.6 F). But when the humidity is 70%, the temperature of 21 degrees Celsius (70 F) will be as suitable as the temperature of 27 degrees Celsius (80.6 F) with a humidity of 30%. As humidity can vary on hot days (this largely depends on the region), the driver must “play” with the temperature, obtaining a comfortable temperature in the car.

If the air conditioning does not work, which most often happens only due to a freon leak, the temperature can not be controlled. What you need to know about this refrigerant:

  • Freon is a colorless gas or liquid that has no odor. In terms of chemical properties, the freon is inert, however, in the event of large leaks, they are seriously harmful to the environment. When heated to high temperatures, they become very toxic. The volume of freon poured into the system depends on the car model and is always indicated on the car’s identity card.
  • the car ac is a complex refrigeration device whose elements are connected by freon wires;
  • a certain percentage of freon is used as a lubricant. The manufacturer adds oil to the freon, as it reduces the wear of the friction parts. And precisely for this reason, the ac must be turned on periodically for 10-15 minutes, to cover with a thin layer the inside of the air conditioning;
  • the frequency of the freon supply in the ac depends on the age of the car. Usually, we add freon to a new car only after 2-3 years of operation, and if the car is more than 7 years old, we add freon every year.

How to fill a car ac with refrigerant

Today, there are only two types of car freons commonly used, the third is fairly new:

  • R12. It has an excellent cooling capacity, low energy consumption. Having in its composition, chlorine, negatively affects the environment. Studies have shown that the long-term use of this refrigerant in air conditioning has negatively affected the Earth’s ozone layer.
  • R134a. According to the thermodynamic characteristics, it is close to the R12 freon, however, it is 10-15% worse in terms of cooling capacity and is more fluid. Today it is often used in refrigeration equipment. In a car ac, using this type of freon 20 years ago was difficult.
  • R1234yf. A new generation of freons complying with the EG / 706/2007 standard. An environmentally friendly gaseous refrigerant, which is unfortunately flammable. Until 2017, it was used quite rarely, but now, according to the decrees of several countries, it will be a priority. Because it is rarely used (and will be for a few more years), we only notice that it is forbidden to mix it with one of the two types of freons above.

So far, only the first two types of freon are being used. But mixing R12 with R134a (and vice versa) is strictly forbidden. Possible faults: accelerated wear of the parts, change in cooling capacity.

More about the differences between freon

When you intend to supply air conditioning with freon, it is important to know what was previously poured into the system. Recommendations are easy to find in the car’s registration card. However, it is not written what is the difference between R12 and R134a, except for the efficiency and some thermodynamic parameters. We will try to explain this in detail:

  • R12 dehydrated freon is neutral to metals and does not have a high degree of an explosion risk, but copper-containing R134a affects the environment. Also, when air enters the freon line and is further compressed, the freon becomes fuel. However, you do not have to worry about the combustible properties of the R134a: the volume of the system is small, so it will not damage the car ac too much;
  • due to the different fluidity, different hoses must be used. This is important. It was mentioned above, but to use another type of freon it is necessary to constructively change the car air conditioning system;
  • the decomposition temperature of both freons exceeds 330 degrees Celsius (626 F). Decomposition products cause health problems. Moreover, R134a is, in some cases, more aggressive towards the human body. However, it does not harm the environment so much.

And finally, a very important question:

If I have R12, can I use a different freon?

Of course, you can use, but only after “updating” the air conditioning system. It costs a lot of money. If the system has already been adapted for the R134a, there is no point in switching to the R12. Moreover, you will save nothing and increase the harmful effect of the car to the environment.

Transfer from one type of freon to another

Almost all changes to car components cost a lot of money. The driver decides if it’s worth it. To switch from R12 to R134a, you will need to replace the following items:

  • Volume. Its replacement is necessary because when using another freon, the heat transfer will also change. Consequently, the capacitor volumes must also change;
  • Connecting the hoses. The new hoses have a nylon inner cover;
  • Expansion valve. Replacement is necessary because the pressure also changes.

The work should only be carried out by professionals. If it is carried out under normal conditions, the pipe, the sealing materials, and the compressor will not last too long.

How do you choose the refrigerant?

First, you need to determine what type of freon was previously used in the system. All the necessary information is indicated in the car manual. However, there is another way to find out if R12 or R134 has been used so far: if the car was manufactured before 1992, the first freon is used with a probability of almost 100%.

Now we will decide how much freon to add. Before starting, you need to check the pressure. You need a pressure gauge station and a set of hoses (usually the hoses are also included in a set with a station at an average price). Also, buy a tube adapter.

Find the air conditioning lines under the hood. There will be two: high pressure and low pressure. The high-pressure line is made of tubes with the smallest diameter. Once you have connected the station through the adapter, start the engine (so the freon will start moving along the pipe) and monitor the pressure readings. Normally it is from 250 to 270. The optimum pressure varies between 280 and 290.

Now you can refill the ac. A one-liter barrel with freon will be enough for several refills. In this case, you still need the same track station. You must connect the system to the bottle and pressure gauge with the hoses. At the same time, the vehicle’s engine should be idling at speeds up to 2000.

The air conditioning is put into recirculation mode. This is followed by refueling itself: once every 2-3 minutes you need to unscrew the pressure gauge valve, monitoring the pressure readings. As soon as the indicators become optimal, refueling can be stopped.

Note: Under no circumstances should dust and dirt enter the trunk. It is recommended to refill as soon as possible. The right places for this are dry, clean, and cool rooms.

It is worth remembering that the quality of the car freon is about the same. This means you don’t have to look very closely at the manufacturer – as long as the type of freon is right for your vehicle.

Usually, those who work with car air conditioning are specialists. And this is not surprising, because the air conditioning system, at first glance, seems simple. In fact, both the design and its repairs require expert skills of specialists with a degree in refrigeration and cryogenic engineering.

However, the driver can do certain things on his own. For example, using special devices called leak sensors, check for the same refrigerant leaks. The driver can refuel the ac.

Most modern cars have ac. And today it is not a luxury, but a necessity. Unfortunately, it requires freon care and filling. According to specialists, freon disappears from the system in the amount of 10-15% per year, so that every year the cooling efficiency decreases. So, it is necessary to refill the air conditioning. Some drivers generally add freon every year, and some, unconsciously, charge it several times a season.

How to recharge the car air conditioning?

Approximately every modern car uses freon R-134a, being manufactured after 1992. Confirmation of this can be a sticker under the hood that indicates the type of freon used in the system and its weight. If you decide to power the car’s air conditioning at home, then first pay attention to this sticker. This way, you can find out exactly what quantity and type of freon you need. When you buy a freon bottle in a store, be guided by this data.


For independent refilling, you will need certain equipment:

  • metrological station;
  • hose;
  • freon bottle for connection;
  • adapter with a tap to connect the station.

How do you recharge the air conditioner in case of a freon leak?

Many drivers refill without thinking about where the freon has disappeared. However, some people know that they have a leak from the air conditioning system, due to which the gas escapes. In this case, it is necessary to refill the air conditioning, but it is important to do it correctly. You can go to a specialized workshop.

But there are other ways to detect leaks. The simplest and cheapest way, which is often practiced at many gas stations, is to apply a soap solution on an air conditioning system. If the solution leaks, then a soap bubble forms and begins to swell at this time. In such a simple and free way it is possible to find a leak in the air conditioning system in 10 minutes.

If a freon leak is detected, there is no point in powering or fully charging the system. In this case, troubleshooting is required. If it is a radiator, then the leak is most often sealed. But there are times when the radiator needs to be completely replaced.

If a leak occurs, it must be repaired quickly. This case should not be delayed for a long time, because after the freon leaks out of the system through the hole in the tubes or radiator, air can enter, and, as a result, it is possible to oxidize some elements of the system or to start the corrosion processes.

Pressure test

Before refilling the ac, make sure that there are no leaks in the system and that it can withstand high pressures. This can be done at the workshop by forcing the pressure in the system, usually with nitrogen.

Nitrogen is “introduced” into the system and the pressure is measured, then wait for about 20-30 minutes, and if the value of the manometer does not change, this means a sufficient seal. In this case, you can refuel the air conditioning alone or at the workshop. Usually, the system check service is cheap.

How much does it cost to charge the car ac?

If there is not enough freon in the system, then there are 2 options: refill yourself or contact a specialized workshop. In a workshop, prices are 45$ – 60$ on average for a full refill. Some drivers do not completely fill the system, but simply add a little amount of freon. This costs an average of 4$ – 5$ per 100 grams. Experts measure how much freon is missing in the system, and add it until the required pressure is reached. 

The prices of standard refrigerant recharging operations, which also include cleaning and vacuuming:

  • standard refrigerant – $ 55
  • ECO refrigerant – $ 135
  • simple sanitation – $ 25

At some service stations, prices are lower, at others higher. However, everyone decides where to refill the ac.

Air conditioning care

Now you know how to recharge the car air conditioning at home. Now let’s talk about the rules of care: wash the radiator at least once every 3 months, because dirt and dust constantly settles on it, which significantly reduces the efficiency of the device.

In winter, you need to heat the air conditioner at least once a month. To heat up, you need to drive the car in a warm place and turn on the cooler for 15-30 minutes. In the event of a leak, contact a workshop to repair the hoses.

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