Got a call on an older W/I freezer (R12 )that had recentley been converted to hotshot by another company. I guess its something I never thought about before until I checked out the LPC settings. Why would anybody have ever wanted to design a pumpdwn system on a freezer using R12? LPC cutout has to pump down into a vacuum and evap operates below atmospheric as well, especially after being converted to hotshot! (-20*F =5.7 psi "hg with 414b) Im sure theres alot of that out there (R12 pumpdown freezers) but why make life hard on the comp and have it operating in the vacuum? The case in question has an old K body cope and seems to have operated like that for years so... If one where to change oil and TXV and use say 404 would not the condenser then be undersized due to the higher operating pressure?