What is a DX cooling coil?

Heat exchangers that convert fluid to air to fluid called DX evaporator cooling coils. In order to ensure effective heat transfer, copper tubes are typically formed into aluminum plate fins with self-spacing collars. The liquid distributor feeds the refrigerant through tubes into individual circuits made of copper return bends that terminate in an outlet header manifold before flowing into the coil. The low pressure refrigerant liquid evaporates and exits the coil as superheated vapour as the warm air passing over the coil transfers heat from the air flowing over the coil's fins and tubes to the refrigerant running through the tubes.

When the air is cooled below dewpoint, the coil assembly is housed in a sheet metal case with a drain tray to catch the condensate that will be formed. Moisture eliminator blades are installed to stop carryover into the air stream in areas where moisture may arise owing to air velocity or condensate load.