The cost to install a wall-mounted AC unit, typically a ductless mini-split system, ranges from $2,000 to $10,500 on average. This includes the price of the unit itself and professional installation. Factors affecting the cost include unit size and capacity, number of zones, installation complexity, and labor rates: Costs can vary by region and the complexity of the installation. For a more accurate estimate, it's best to get a quotes from your local Carrier dealer.