The properties, and what they mean at the bench.
Reference notes on the refrigerants, oils and chemicals used in automotive air conditioning and thermal management.
Written for the workshop
Each entry covers what a substance is, how it behaves, the safety classification and environmental figures that govern how it must be handled, the applications it is found in, and the service procedure it calls for.
These notes are a reference, not a substitute for the vehicle manufacturer’s service information or for the regulations that apply where you work. Where the two differ, the manufacturer and the regulator win.
Refrigerants
Safety classification, global warming potential and the service procedure each one calls for.
Common questions
What do the safety classifications mean?
The letter is toxicity and the number is flammability. A1 is lower toxicity with no flame propagation, A2L is lower toxicity and mildly flammable with a slow burning velocity, A2 is flammable, and A3 is highly flammable. The class decides the equipment, the ventilation and the handling procedure a refrigerant requires.
Can I use a lower-GWP refrigerant in an existing system?
Only where the vehicle manufacturer or a recognised retrofit procedure permits it, and with the correct adapters, lubricant and labelling. Charging a system with a refrigerant it was not designed or converted for is unsafe and can damage it.
Why does the oil matter as much as the refrigerant?
The lubricant has to be compatible with both the refrigerant and the compressor, and it circulates through the whole system. The wrong oil, or the right oil contaminated, will shorten the life of a compressor more reliably than almost anything else.
Need the equipment to work with these?
Service machines, identifiers and adapters for the refrigerants above.