While installing the AC, the technician will first choose a suitable location for the AC. Then, he will adjust the mounting plate and drill a hole to connect the indoor and outdoor units. Next, he will mount your AC unit. After installation of the indoor unit, holes are drilled for the outdoor unit to get it installed over a bracket. The next step involves connecting the cables and copper pipes. If your AC system is ducted, the ductwork will get installed before the installation of the AC unit.