I'm trying to see if this is a problem before I call the installers. When my a/c is running the copper lines going into the compressor are not very different in temp. I would describe the small line as room temp and the larger insulated line as slightly cool. I remember reading somewhere and it would make sense that one would be hot and one cold. The a/c seems to work ok but the outside temp hasn't been over 80 since the install so it's hard to say. The supply air is cool but not anywhere near as cold as even my window unit. The temp difference from return to supply is about 10-12 degrees by using a temp gauge. Does this sound ok or should I have them look at it? Thanks!