In larger residences, commercial buildings and in particular multi-story buildings, "split" central air conditioning becomes a less effective cooling system. The ductwork becomes unmanageably long and/or the pipe running between the condenser and air handler exceeds distance limitations; causing lubrication difficulties in the compressor. In Chilled Water systems, a unit placed behind or on top of the building chills water and runs it through pipes, passing through coils in air handlers where air becomes cooled and blown into the room.
