A DX Fan Fan Coil Unit (FCU) is a type of air conditioning system that is designed to provide cooling and/or heating to a space. It is a self-contained unit that consists of a fan, coil, and a filter. The fan draws in air from the space and passes it over the coil, which is cooled or heated depending on the desired temperature. The filter then removes any dust or other particles from the air before it is sent back into the space. DX FCUs are often used in residential and commercial buildings, as they are relatively easy to install and maintain. They are also highly efficient, making them a cost-effective option for many applications.