Abstract: Devices, methods of using the devices, and kits are described that provide a protective barrier device between an air delivery structure of an air conditioning unit and the ceiling components that are adjacent to the air delivery structure. The device is a unitary water-impermeable structure having surfaces that act as barrier, preventing condensation collecting on the air delivery structure from passing to the sorrounding ceiling components. A preferred embodiment of the invention has a surface projecting into the space being cooled, said surface deflecting air from the adjacent ceiling structures, thereby reducing or preventing collection of dirt or other particles, or moisture, from depositing on the adjacent ceiling components.