DX(Direct Expansion) Coil for AHU

DX(Direct Expansion) Coil for AHU

A DX (Direct Expansion) coil, also known as a cooling coil or evaporator coil, is a key component in an Air Handling Unit (AHU) that is responsible for cooling the air as part of an air conditioning system.

The DX coil is typically located downstream of the AHU's supply air fan. It consists of a series of copper or aluminum tubes with fins attached to them. These tubes and fins form a heat exchange surface that allows for the transfer of heat between the air and a refrigerant flowing through the coil.

The process begins with the AHU's supply air fan drawing warm air from the space into the AHU. The air passes over the DX coil, where the refrigerant inside the tubes absorbs heat from the air. As a result, the air is cooled and then delivered back into space.

The refrigerant used in the DX coil is typically a liquid that evaporates as it absorbs heat from the air passing over the coil. This phase change from liquid to gas allows the refrigerant to carry the heat away from the coil more efficiently. The refrigerant gas is then compressed by a compressor located in the air conditioning system, and the heat it absorbed is expelled outside the building through a condenser unit.

The DX coil in an AHU plays a crucial role in the cooling process, as it is responsible for extracting heat from the air and lowering its temperature. The cooled air is then distributed throughout the building to achieve the desired indoor temperature and comfort.

It's important to properly size and select the DX coil for an AHU based on the specific cooling requirements of the space. Factors such as the desired cooling capacity, airflow rate, and temperature conditions need to be considered during the design and installation process.