I have a question for a qualified expert, such as yourself. I was told recently by another tech that all A/C systems are 'closed', and as such, should never lose a drop of refrigerant, ever.
In the past, I've always been under the impression that a tiny bit of refrigerant will be lost through automotive compressor seals to the atmosphere, and that adding a small amount to top it off every few years is considered normal.
The tech I spoke with mentioned freezer/refrigerator units in our conversation as well, saying that they never need recharging as well. All of these units I've seen use sealed compressors; same goes for industrial HVAC systems. Automotive compressors look to be a completely different animal; they're not sealed, and the compressors operate under varying temperature and input shaft speeds.
What's your take on this? Every automotive A/C application I've ever known required occasional servicing, and all seemed to naturally use a small amount of refrigerant over time, whether operating or not.
-JD
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