noob questions - automotive AC mostly. R 134 (A) , Enviro-safe R134 A replacement, and leak sniffers

[Tmoose]

I plan on some experimenting.
BUT, in the mean time, Would you expect low end detector for nat gas, propane or butane to be useful for sniffing for AC leaks? Like a General PNG2000A for instance?

The Enviro-safe R 134A replacement seems to be some kind of hydrocarbon mix, so I'm thinking the PNG2000A should tend to work sniffing out leaks at some level.

thanks,

Dan T

 

[HVAC-Novice]

Unless propane is the refrigerant, why would you think it works?

You can spray soap water on the system to find bubbles. But in general you should let someone with the knowledge and equipment work on refrigeration systems. You also need to have the EPA certification. Section 609 for cars.

And why do you think you can use a different refrigerant? I mean, you can, it just won't work well.
EPA does not recognize replacement refrigerant. That doesn't stop manufacturers from claiming to do so. If the replacement refrigerant doesn't flat out ruin your system, it will perform worse. Look at the replacement bottles and try to find the written guarantee that it will work equally as well and that they will pay for any damages.

 

[BrianPetersen]

Refrigerant 1234yf pressure temperature chart:

https://www.consulab.com/files/r1234yfPtChart.pdf

Note that 0 C gives 31 psig (i.e. 45 - 46 psia) and 50 C gives 174 psig (188 - 189 psia). Refrigerant 134a is very similar.

A 50/50 blend of propane and butane comes pretty close to that.

https://www.engineeringtoolbox.com/propane-butane-mix-d_1043.html

Certainly the expansion valve in an automotive A/C system is not designed for propane-butane mix, but this doesn't seem to stop companies from selling cheap substitute refrigerants.

I recharged the A/C in an old car with the substitute refrigerant. It did not have the same cooling performance, but it was much better than not having air conditioning at all, which was the case before I recharged it.

A hydrocarbon detector will probably detect leaks if the system has been recharged with the substitute refrigerant, but I would not expect a hydrocarbon detector to detect a hydrofluorocarbon. Maybe ... maybe not.

 

[HVAC-Novice]

Sounds like a new "Florida man....." news story. Just add a combustible high-pressure refrigerant to a car designed for non-combustible refrigerant and the Darwin Award will be yours in not time....

You also need compatibility with the oil, and the seals etc. What exactly is wrong with using refrigerant the system was designed for?

You also would need to evacuate the system before filling any new refrigerant. Just bring it to a shop that has the equipment and expertise and the correct refrigerant.