An air conditioning system includes a housing defining a first airflow path therein between an outside air inlet over a cooling coil and an outlet for delivering outside air from the outside air inlet over the coil to the outlet, a second airflow path between a return air inlet over the cooling coil and to the outlet for delivering return air over the cooling coil, and a third airflow path between the return air inlet and the outlet for delivering return air through the housing without passing over the cooling coil. The system includes outside, return, and bypass air dampers that are sequentially moveable between open and closed positions for directing air through or preventing air from entering the first, second, and third airflow paths, respectively. A controller independently controls the opening and closing of each damper in response to data received from the sensor.