View Full Version : R134a odour

16-12-2013, 10:59 AM
Virgin R134a has an ethereal smell, however, I have noticed after a period of use in a system combined with POE oil there is a strong smell. Has anyone else encountered this and has anyone investigated the reason?

01-01-2014, 01:22 PM
Check the value of acidity of the oil, can be the cause


Rob White
01-01-2014, 07:17 PM

Refrigerants to me have no smell because I have a poor sense of smell
(except for Ammonia :cool: ) so the only thing I smell is either the
oil or the refrigerant that is thermally decomposed (burnt out).

I do know that if 134a runs near to its critical point it will break down
and then it smells burnt (if you lose some when fitting gauges).
134a that is in a system with a blocked condenser or a faulty condenser
fan often runs hotter than it's critical temperature (or near to it) and
that often burns the refrigerant (thermally decompose). The only way
to put it right is to replace the refrigerant for new (after cleaning the condenser).

Smelly refrigerant is often put down to a burnt out compressor, but the refrigerant
can break down if allowed to run too hot for too long.



02-01-2014, 07:46 AM
Brilliant explanation Rob.
Like you I have a poor sense of smell!
So any unusual smells are investigated nowadays.

02-01-2014, 09:20 AM
Yes, I think it is due to the R134a breaking down too. It seems to happen quite a lot, but not with other refrigerants - unless, as you say, there is a problem with windings burning out or extreme heat.