Cool Prospects With R744

2023 Author: Eric Donovan | [email protected]. Last modified: 2023-11-27 05:39

It's not just the cars that have to make savings in terms of CO2. From 2011, limit values for refrigerants in air conditioning systems will be set. Two competing models vie for supremacy.

By Heiko Haupt Telling

a car driver that CO2 can also be a good thing is likely to meet with complete incomprehension at the moment. But when it comes to air conditioning, switching to CO2 is actually an issue. The background to this is the fact that the systems need a refrigerant in order to function at all. So far, these agents have not been considered particularly environmentally friendly - which is a particular problem because an air conditioning system is never completely airtight. Alternative refrigerants, such as CO2, are therefore to be used in the future.

Additional costs in the foreground

But while it previously looked as if a decision had already been made in this context, there is now again eager discussion. The final decision is not only made from an environmental point of view - it is also about the cost of the cars.

One thing is clear so far: According to an EU regulation, from 2011 car air conditioning systems may only be filled with a refrigerant that does not exceed the new limit values with regard to the destruction of the environment or ozone. These values are measured in numbers that describe the “Global Warming Potential” - that is, the global warming potential. As of 2011, this number must not exceed 150. So far, air conditioning systems contain an agent called R134a - and its global warming potential is 1300.

Competition for R744

The manufacturers of refrigerants do not have catchy names anyway: When it comes to the future, R744 on the one hand and 1234yf on the other are currently named as competitors. The really surprising thing, however, is that both remedies are being talked about again at all.

At first glance, everything was already clear in 2007 - at least if the Association of German Automobile Manufacturers (VDA) in Frankfurt / Main had it: "The VDA has made it very clear that it is going for the R744," says Hubert Paulus from the ADAC technology center in Landsberg (Bavaria). A statement that was also welcomed by environmentalists: R744 is synonymous with the natural refrigerant carbon dioxide. And while CO2 is almost a dirty word with regard to exhaust gases, it is seen as a savior by not a few experts in the field of air conditioning: If the global warming potential of the current refrigerant is 1300, R744 has a value of just 1.

1224yf armed

Nevertheless, the natural CO2 agent R744 no longer appears to be the only alternative for the future. With the result that the German Environmental Aid (DUH) in Berlin accuses the auto industry of "trickery against the environment". Accordingly, despite their announcement, manufacturers are now interested in a chemical alternative to cooling with CO2 - the coolant with the designation 1224yf.

In fact, there are reasons for new things to come into play: “CO2 as a natural refrigerant would certainly be the best choice when it comes to the environment”, says Hubert Paulus. "However, this requires new technology for the air conditioning systems - which will lead to additional costs." The mean 1234yf, on the other hand, does a little worse than the CO2 competition in terms of global warming potential: Instead of a value of 1, according to Hubert Paulus, you get a value of 4 - which is still a step forward compared to the current refrigerant. The main advantage is that the product can also be used with existing technology.

Ambiguity in detail

According to Hubert Paulus, there are still ambiguities around 1234yf. Since the remedy is new, little is known about the details. "Among other things, the long-term consequences are unknown." It is about what happens if the agent is exposed to the air in an accident. In addition, 1234yf should be flammable. "The industry still has to clarify whether this is really manageable in the car."

It goes without saying that the proponents of the drug do not see these questions as a hindrance: "We are of the opinion that it is a sensible alternative," says Horst-Ulrich Reimer from Dupont in Bad Homburg. The company is working with Honeywell on the development of 1234yf.

Agreement as the best solution

What ultimately goes into the cars still seems unclear. Because the VDA confirms the statement from the previous year - and keeps alternatives open. "We're working on the CO2 refrigerant," says spokesman Eckehart Rotter. "But we are also reviewing the alternative."

Experts like Hubert Paulus hope that car manufacturers around the world will really agree on one of the two options in the end. Not only with a view to the environment - but also because in terms of costs for the driver, the number of units also matters: If the CO2 systems were installed in all cars, the surcharge would be significantly lower. (dpa / gms)