The indoor unit of a split-type air conditioner should be mounted high on a wall in a location that allows cool air to be distributed evenly throughout the room without being blocked by furniture, curtains, or partitions. It should be positioned away from direct sunlight and heat sources, and the installation wall should be strong enough to support the weight of the unit securely. Equally important is the proximity to the outdoor unit, as longer refrigerant line sets reduce efficiency and increase installation costs, so placing the indoor unit on a wall that is closest to where the outdoor unit will be mounted is the most practical and cost-effective approach.