Thank you for your courteous advice. Here is my situation.
I live in a condominium. My residential location is entirely on the second floor of a building. My neighbors live on the first floor. The outdoor unit is on the ground outside. The lines run through the walls up to the second floor. My ducts are in the attic. The flow of air inside is from the top of the room to the bottom of the room.
The cost of breaking through walls is prohibitive. It is unlikely that the condominium board will approve my breaking through the exterior and running another line along the exterior side of the building.
If you have a reasonably priced, creative solution, I will welcome it.
If an installer tells me that a unit which specifies 3/8 inch lines can be used with 1/4 inch lines, provided that I install a TXV, is that installer incompetent?
How do I find a list of those models which can be used with 1/4 inch lines?