Air conditioning has ceases to become a luxury and is now considered to be every home and commercial establishment’s requirement. However, the nature and scope of the buildings intended to be cooled tend to determine the kind of air conditioning system needed. From an eighth storey and down, commercial and residential air conditioning establishments seem to be doing the same service: controlling indoor temperatures and improving indoor air quality. They are, however, very different systems, and these differences are of great importance in designing them for nuances in function.