Abstract: An air-conditioning unit is positionable through a partition such as a wall. The unit has a housing passing through the wall and a plate covering the inner end of the housing. The evaporator coil is mounted on the plate. A further plate extends from the plate horizontally into the housing and the compressor and condenser are mounted on the further plate. An aperture leads through the first mentioned plate for the passage of air and leads to an elongated duct to provide sound attenuation. Sealing gaskets are provided between the housing and the first mentioned plate and sound deadening material is positioned to deaden sound on the housing and the first mentioned plate.