Air Condition is considered as the most important things we think about within designing the buildingA.Cs have many types ( split - central ) and both types has advantages and disadvantages.accourding to these points we had to think about a new type which combines both advantagesand this type called ( ducted split unit ) or ( Ceiling Concealed Duct Type ).this hidden A.C created from 2 units:First: internal unit ( the fan ) which is built inside the building and connected with the duct which allowed the air flowing Second: external unit ( compressor ) which built outside the building and connected to the internal unit by copper pipesShortly, it's the same idea of split AC ( outdoor and indoor unit ) but here the internal unit (fan) is hidden into rented roof.Quiet, it's quiter than the split AC.Cheappr than Central ACSuitable for All building designs