R134a phase out and its replacement

[Aurel STDL]

Hi, Im interesting regarding replacement of R134a. There is an restriction about using this refrigerant in automotive A/C systems. What about other industry like heat pumps systems or ORC?
What is the appropriate replacement?

[NiHaoMike]

R600a and/or R290. They're flammable, but so is R1234yf.
http://uk.reuters.com/article/2012/1...8BB0HE20121212

[The MG Pony]

heat pumps and such R-290 is a more apt replacement for old r-22 based systems, for R-134a systems you need an HC blend to match it.

nice thing about hc, is very good at moving oil, so some of things to be mind full is, you need a thicker oil, you need to impliment accumulater and compressor sump heaters, some adjustment may be required for txv once system is at a stable opperating temp and mode, and take care to reduce the amount of charge according to the mixes spec.

Other then that you will notice great things like reduced compression ratios, excellent load performance at high condencing temps, excellent oil carry over, so your evap will run great, reduced issues with wax if you where having them as it is soluable in the HC

[camelCase]

HC's have very high oil solubility. Like MG Pony said - you may need to step up your viscosity to maintain lubricity in the contacting components. The good news is that HC solubility in oils is temperature and pressure dependent. As pressure drops and temperatures rise - the solubility goes down. This is good since the compressor inlet is hot and low pressure - so it will help drive some of the HCs out of your lubricant.

I know in the US car makers have until 2017 IIRC to get R134a out of their systems. Europe already requires it to be gone (France won't let cars register that has R134a in them). Many automakers are switching to 1234yf b/c it's cheaper and easier to deal with compared to CO2 (their only other real option for the application).

[willklaus]

HFC-152a, CO2 R744, HFO1234yf are possible options. 152a is flammable which means additional equipment and weight on vehcles. CO2 system is high pressure which can be used in large system, but car a/c may need major change to the system. HFO1234yf should be the best replacement, however Honeywell and Dupont owns almost all the patents here, it's a monopoly business.

[NiHaoMike]

The flammability issue is way overstated in automotive applications where there's already a lot of flammables. R152a, often used in dusters and other aerosol products, has been successfully used in automotive A/C, cooling better than R134a and and being slightly more efficient. But I think a mix or R290 and R600a is the way to go for automotive.

[superslim007]

R1234YF is classed as slightly flamable, its like the difference between petrol and diesel - if you drop a match in diesel it goes out if you drop it in petrol well!!