Ducted Air Conditioning is defined by its ducting system made up of a heat exchanger located outside. With ducts constructed from flexible cylindrical tubes hidden from plain sight located in ceiling voids. Also, commonly referred to as Channel Air Conditioning or Central Air Conditioning. This is most often noticed in massive or older buildings and is a preferred system. Ducted Air Conditioners are hidden in ceiling voids, they have the advantage of delivering clean air to many rooms throughout a building. Pushing air through ducts and each room or zone can be adjusted independently. Ducted Air Conditioning is by far cleaner, quieter and still the best way of distributing clean air throughout a large building with many rooms. Starting from 24 000 BTU and ending at 48 000 BTU.