S-Prihadi

Guys,

Interesting reading here : https://docs.lib.purdue.edu/cgi/view...9&context=icec

Important points :
01. Static non spinning compressor with new generation seals, average 7 grams per year at 147PSI . My car AC off R134a pressure is 6.6 BAR or 96PSI at 30C.

02. Spinning compressor shaft, get oil bath, average loss 0.3 grams per year if shaft is highly polished.

See No 6. Conclusions, at ending page (8).


Now, aside from mechanical sealing itself between seal to compressor shaft, all these seals be it dynamic or static one, has natural gas permeation rate. Example : https://www.marcorubber.com/o-ring-permeation.htm
A home fridge is hermetically sealed system, that is a different animal https://electricalworkbook.com/herme...ommon%20casing.


Typical W212 uses 590 grams of R134A


We all wish we have the damn good seal at 7 grams lost per year maximum.... we wish

Anyhow, it looks like 10 years is a good time to verify the r134a weight/content in our car. Low refrigerant level can harm compressor because of how the compressor oil can fail to return back to the compressor.

Here is a good book, free : https://www.lee.k12.al.us/site/handl...HVAC-eBook.pdf
https://www.melioronline.com/

"A low charge level doesn't just reduce the system's cooling capacity; it can also cause compressor oil starvation. Because oil is circulated inside an A/C system by being suspended in the refrigerant, operating an undercharged A/C system can cause compressor seizure. Studies have shown that as little as a 10% to 20% undercharge, which can be as little as 3 ounces (85 grams), can cause oil circulation to decrease by as much as 80%." PDF page 26


Enjoy and learn.



The more I know on how cleanliness + dryness + vacuum level down to 500 micron or better........ for HVAC and software controlled variable displacement compressor unique pressure and operational algorithm and different car to car/brand/model,
the more I realized it is actually complex enough if one seek perfection on HVAC job conducted on our car.