DX units are types of air conditioning systems that directly cool the air supplied to a building. They come as split or packaged systems.
Direct expansion, or DX, air conditioning units feature evaporators that are in direct contact with the supplying air. The evaporator absorbs heat from the air supply by expanding the refrigerant, which then flows to a compressor. The compressed refrigerant moves to a condenser, releasing the heat absorbed from the air supply. The final stage of the cycle is the flow of the condensed refrigerant back to the evaporator.
DX units take up less space than centralized cooling systems and can be less costly to install. They come in two types: split or packaged.
- Split DX units Split DX units generally have the evaporator and fans inside the building, with the remaining components situated outside, making the unit more flexible to install. As parts of the system are located away from the cooling area, the noise levels are lower.
- Packaged DX units Packaged DX units contain all the components in one system, as well as the internal ducting and fans. The units are easier to install than split units for local zones in buildings. They generally occupy less space and require less ventilation.