A DX unit uses refrigerant-based cooling and cools indoor air using a condensed refrigerant liquid. Direct Expansion means that the refrigerant expands to produce the cooling effect in a coil that is in direct contact with the conditioned air that will be delivered to the space
The DX System works in such a way that the evaporator is located in the space to be refrigerated. When the refrigerant in the evaporator coil expanded, it will cool the space by absorbing the heat from it. The mini splits, window air conditioner and packaged units are examples of such system.
A direct expansion air conditioning system, or DX unit, directly cools the air supplied indoors using a condensed refrigerant liquid. They are less expensive, requires less space and has low noise levels.
