Tumpany tanya here

The bedroom at second floor (2 storey terrace) is in need of new aircon replacement. Currently using non inverter from more than 10 years old

The problem is with concealed piping (within walls i think) and the outdoor units was installed on the middle roof (the place where water tank also placed there) for aesthetic reasons

If upgrade to inverter aircon, is it easier to put new piping/wiring outside and put the new outdoor unit into new place (like wall outside) rather than redo the concealed piping? Can i leave existing piping and odu alone when installing the new one. Because the newer gas and inverter replacement will implies new piping as is upgrading from very old to newer model