> You typically need to completely vent the system for any maintenance on a refrigeration system anyway On residential/small systems where it's commonly used t

> You typically need to completely vent the system for any maintenance on a refrigeration system anyway On residential/small systems where it's commonly used today, sure. For larger systems this is not true. You're typically going to have a receiver and a valve you can use to store the charge entirely in the receiver. Then you can work on the system without having to dump or capture that charge. It also allows you to have additional cooling circuits, so you're starting to see this incorporated into smaller commercial designs for the additional cooling efficiency. > I think lack of ports is simply to save money They're required to be hermetically sealed in the US by IEC and in most Pacific Island countries by law where they're more commonly used in residential applications.