Short answer: Before installing a split AC, confirm a strong wall for the indoor unit, a shaded and ventilated spot for the outdoor unit, the shortest practical pipe route, a dedicated earthed power point of the right rating, and a drain route with a continuous downward slope. During installation, insist on vacuuming before the gas is released and a leak check at every joint.

Before the Technician Arrives

[ ] Indoor unit wall: solid, high, clear of curtains, not blowing straight onto a bed
[ ] Outdoor unit spot: shaded if possible, open in front, 30 cm clear behind, safe to reach for servicing
[ ] Pipe route: as short and straight as practical; note the length for extra copper costs
[ ] Power point: dedicated 16A, properly earthed, adequate wiring for the tonnage
[ ] Drain route: where will the water go, without staining the wall below?
[ ] Building rules: some apartment associations specify where outdoor units can go