Installing a brand-new split AC in a Dubai apartment — what's actually involved in doing it properly?

You're right to focus on the install, a good unit fitted badly fails early, and the part that's skipped is usually the one that matters most. A proper split installation is: correct sizing for the room (not a guess), sensible siting of both units for airflow and service access, a clean pipe run with proper insulation (lagging) and a correctly-sloped condensate drain, and then the commissioning, evacuating (vacuuming) the pipework to pull out air and moisture before releasing the refrigerant, then checking the charge and running operation. That vacuum step is the one rushed installers skip, and it's the classic reason a new AC cools poorly, ices up or fails within a year, because moisture and air left in the lines quietly wreck performance and the compressor. So insist on: a sizing basis, insulated pipework, and above all that they vacuum the lines and commission it properly, not just gas it and go. A proper AC installation in Dubai does the vacuum and commissioning as standard and hands over a unit that actually performs, ask them directly whether they evacuate the lines. Getting siting right also saves you on future servicing access.