Macrobb
Full Access Member
And, it depends on the compressor. The compressors in the bricknose/bullnose trucks seem to be much more... sturdy than the newer ones in the OBS trucks. I've pulled a couple of siezed OBS units apart, and they absolutely depend on plenty of oil - it's literally sliding steel on aluminum to rotate. No oil(or not enough) = galling of the aluminum = dead compressor in very short order.
The older York-style compressors with their own oil sumps? Those, you don't need any oil in with the refrigerant, because it's a wet-sump compressor and the oil is "outside" of the refrigerant loop.
The older York-style compressors with their own oil sumps? Those, you don't need any oil in with the refrigerant, because it's a wet-sump compressor and the oil is "outside" of the refrigerant loop.
I'm not going to say that it can produce temps below freezing at the evaporator if you wish...After all that, I charged up with HC-12 and never looked back. It's legal, works great, and I don't need a license so I can do as I please without any "interference". Heck, I'd even be tempted to try straight propane like one guy did a while back. Not likely now that everything works fine, but still, I can't help but wonder how well it could be made to work.