Actually it is a matter of length. We just had a two unit system installed and the installer told me if we didn’t have a 25 foot minimum run he would have to bury some outside. A shorter run will cause the inverter to cycle too often. He mentioned that the house he just bought has the problem because of a poor installation and he needs to fix it. Another issue with our system is it uses flared fittings rather than soldered and they would never hold up. The ducted mini-splits are great systems and can be squeezed anywhere and are really quiet. This was our second installation with the previous one in a 150 year old house.
Dave