retrofitting with non-cfc substitutes

RETROFITTING WITH NON-CFC SUBSTITUTES
Alternatives Conference, 20-22 October 1993, Washington, D.C., U.S.A. pp. 312-316
Problems
There are differences between CFC-12 and HFC-134a with regard to capacity, coefficient of
performance, and compression ratio. Cleaning of the system and providing the system with
HFC-134a compatible components and lubricant. The author recommends strict adherence to
SAE 1660 and 1661 specifications that the system be cleaned properly.
Dekleva, T.W.; Colmery, S.H.; Bresnaham, John, 1993: Fleet trials with vehicles retrofitted
to Klea 134a refrigerant and Emkarate RL lubricants; a perspective after two years on the
road. Paper presented at the 1993 International CFC and Halon Alternatives Conference,
20-22 October 1993, Washington, D.C., U.S.A. pp. 294-30
Benefits
Many of the barriers to introducing mobile air conditioning retrofits are being successfully
addressed through the considerable efforts of the industry. Available data suggests that vehicles
retrofit under a range of conditions show good performance and durability. Service practices for
retrofit vehicles are considered comparable to vehicles running on CFC-12. The current status
of our fleet studies continue to show results and promise for the introduction of HFC-134a as
a retrofit refrigerant. Performance levels appear to be acceptable for the majority of owners and
conditions, and there have been no systematic performance or durability issues.
Low toxicity. Thermophysical characteristics similar to CFC-12. Residual system CFC-12
appears to be a manageable partner.
Observations
Some question still exists about the use of epichlorohydins with PAGs and certain HNBRs with
CFC-12/mineral oil, but by-in-large, it appears that most other materials existing in CFC-12
systems (with the exception of Viton) can withstand retrofitting to HFC-134a.
Rubber hoses: Available literature suggests that HFC-134a permeates through rubber hoses up
to 50% faster than does CFC-12.
Desiccants: The total available information suggests that, while replacing the desiccant with
new HFC-134a compatible material is preferred, using the XH-5 material will not lead to
catastrophic results.
Hobbs, Arthur, 1993: Supply, distribution, and availability of mobile air conditioning parts
for retrofit of CFC-12 systems to HFC-134a. Paper presented at the 1993 International
CFC and Halon Alternatives Conference, 20-22 October 1993, Washington, D.C., U.S.A.
pp. 304-311
In the last four years, Four Seasons has retrofitted its own vehicle fleet. Testing of this fleet is
continuous with very favorable results.
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