Abstract: Air conditioning apparatus is provided in which an air blower and an electric heater assembly are located in a common housing with the heater assembly projecting into the housing from a wall thereof in transverse relationship to the blower. This configuration eliminates the need for a dedicated space for the electric heater downstream of the blower housing, which reduces the size of the apparatus. The wall of the housing includes an opening through which the heater assembly is insertable into the housing. The heater assembly includes a mounting plate to close off the wall opening and to removably mount the heater assembly with the housing. The heater assembly preferably further includes an open coil electric heater, with a major dimension of the heater being oriented generally parallel to the direction of air flow in the blower housing.