An air cooled condensing unit is an enclosure for one or multiple condenser fans, compressors, coils, piping, and controls. Its purpose is to provide cooling to a building via a central station air handling unit. Condensing units are the outdoor section of a split system (A split system is simply an HVAC air conditioning system in which the air handler and condensing units are separate pieces of equipment) and cools the refrigerant which is circled through its cooling coil.