Different refrigerants for the car air conditioning system

The widely used refrigerant r134a may no longer be used in new vehicles from the end of 2016 due to an EU directive on environmental protection. The new alternatives r1234yf and R744 (CO2) are more environmentally friendly, but also have their pitfalls. We tell you what to look out for

The "old" refrigerant r134a

The refrigerant r134a is colloquially called "the old refrigerant". Old, because their use in new cars will be banned from january 2017 due to their damaging effect on the climate.

The "new" refrigerant r1234yf

After it became clear that r134a would be banned, car manufacturers agreed on r1234yf as an alternative. The advantage is that only minor modifications are required to the existing air-conditioning systems, thus saving high development costs. However, the r1234yf costs about 140€ per kilo, while the r134a is only about 8€ per kilo. As a result, the price of the air-conditioning service rises sharply, which is often not understood by the customer.

Since 2012 the r1234yf is used in some cars. This liquefied, colorless gas has a faint inherent odor and is much more climate-friendly than r134a. However, it is classified as highly flammable and the auto-ignition temperature is 405°C.

The new alternative CO2 (R744)

Mercedes benz was not satisfied with r1234yf and therefore developed a new air conditioning system for CO2. From the end of 2016, the new S-Class (model 222) and the E-Class (model 213) will initially be equipped with this type of air conditioning system. Other carmakers are expected to follow suit and switch to CO2 air conditioning in the medium term.

The advantages of the CO2 (R744) refrigerant are obvious:

  • 1430 times lower global warming potential than r134a
  • Non flammable
  • High cooling capacity
  • Attractive price with approx. 26€ per kilo

Is it allowed to fill a r1234yf air conditioner with r134a??

No, this is not allowed by law and mixing should be avoided at all costs. Through various service couplings and the use of an air conditioning service unit with a refrigerant analyzer, any possible mix-up of refrigerants is immediately detected. This avoids damage to the air conditioning system and thus consequential costs due to contamination.

How to ensure safe handling of refrigerants?

As with all chemicals, certain precautions should be followed to ensure safe handling. The recommendations for the workshop are:

  • At least one air change per hour in the entire workshop area
  • In pits, at least three air changes per hour
  • Exclusive use of suitable air-conditioning service equipment
  • Open fire and light as well as ignition sources such as the arc during welding must be kept away
  • For all refrigerants, protective equipment should be used when handling them, e.g.B. Long-sleeved work clothing to be worn.

In addition, air conditioning services must only be carried out by qualified personnel. Every employee who carries out activities in connection with air conditioning systems requires a training certificate in the form of a certificate of competence for air conditioning systems.

These air conditioning service units are required

To be equipped for each refrigerant, different air conditioning service units are needed. These must be labeled in such a way as to avoid confusion, as the different properties require different technical concepts and designs. In addition, the air conditioning service units for r134a and r1234yf have different service couplings.

For those who do not want to have two air-conditioning maintenance units, the texa konfort 780R bi-gas air-conditioning service unit is an alternative. This is as big as a "simple" air conditioning service unit, but both refrigerants can be used in the same unit.

In the medium term, workshops will have to add a CO2 R744 air conditioning service unit to their equipment in order to be equipped to service new cars fitted with it. the use of other air-conditioning service units is not possible, as five times higher pressures prevail in CO2 air-conditioning systems and therefore different requirements are placed on the air-conditioning service unit.


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