Distributed Direct Expansion
Distributed Direct Expansion

This system is similar to the centralised DX except that the compressors are usually located adjacent to, or within the condenser housing.

Instead of a central plant room, a number of smaller compressors are mounted within each condenser unit. The condenser units are usually roof mounted, with each unit positioned directly above a group of cabinets so that long refrigerant lines are avoided. The condenser units can be factory-assembled, which enables their quality to be closely controlled and streamlines the construction process, making it faster, more efficient, safer and less costly.

This approach also reduces the refrigerant charge and leakage rate due to smaller diameter pipe sizing. However, it is not always practical; whether or not it can be used depends on the location and structure of the building.