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New refrigerant is not an alternative to R134a

SERVICE INFORMATION
Bulletin Nbr: 854-1680
Date: ........... JUNE 1996
Market: S
New refrigerant is not an alternative to R134a

Cars concerned

All Saab 900 and Saab 9000 with A/C–system containing refrigerant R12.

Background

Alternative refrigerants to R134a are being marketed. Yet another one of these alternatives is Isceon–49 from Rhone-Polenc.

I-49 consists of a mixture of R134a (88%%), R218 (9%%) and R600a (3%%) and is said to be able to replace R12 directly without an oil change being necessary.

Without oil solubility

There is no oil solubility in mineral oil, which is why it is just as bad to drive with I–49 on mineral oil as it is with R134a.

One effect is that the mineral oil in the R12 systems has a chemical make-up that is not suited to be mixed with R134a or I–49, which means that it will not lubricate the compressor sufficiently. The old mineral oil must be removed so that it does not form an insulating film in the evaporator, which would noticeably worsen the cooling performance of the A/C system.

Despite this, certain systems can be driven on non-soluble oil but experience shows that this leads to an increase in breakdowns.

Service availability

Since the market is standardised for R134a, the service availability for uncommon media such as l–49 cannot be guaranteed. Furthermore, refrigerants must not be mixed according to law, which means that there must be separate reservoirs and tools for I–49.

In addition, Isceon-49 contains among other things R218, which has an extremely long atmospheric lifespan. This substance gives the refrigerant a high greenhouse effect, which is against Saab's efforts to reduce the use of materials having a negative effect on the environment.

Diagnostic procedure

Saab therefore does not recommend the use of Isceon–49 as a replacement for R12.

I–49 is just as bad to use with mineral oil as R134a and consequently there is no reason for using I–49.

In addition, servicing can not be guaranteed and separate reservoirs and tools must be produced.