Direct Expansion (DX) Type of Central Air Conditioning Plant or System. The DX Air Conditioner system uses a refrigerant vapor expansion and compression cycle to cool air coming in through a supply plenum and returns it to the area that needs cooling through the return. The unit effectively circulates refrigerant through a series of condensers and evaporators, which warm air moves through and is cooled down before being pushed through the return. Another key feature of DX systems is the advantage of having the entire cooling system self-contained in one unit. This allows for the installation on top of or alongside a building without too large of a footprint, and are generally less expensive to install.
