A mixed air conditioning controller is formed as a factory assembled and adjusted unit in a compact housing, with simple and direct input/output field connectors. Various temperature and humidity input devices are field connected to produce a sequenced control of the air dampers and mechanical cooling and heating devices, as well as auxiliary devices. The controller includes a primary input related to room demand, an outside air temperature input, with an interlocked control to the damper, a fan status input, a minimum air supply control and a by-pass switch having a low limit input. The logic network connecting the input/output includes pneumatic switching, pressure selecting and comparing devices of a diaphragm-controlled-orifice construction connected to function as fluidic repeaters, pressure regulating valves and pressure isolating and switching devices. The controller includes a conditioning channel and a damper channel. An outside air interlock controls the damper channel and a presettable switch controls the minimum air supply control. The presettable switch also includes a low limit temperature signal input. An auxiliary output may drive a humidity controller having a conditioning channel and a humidity channel. The humidity controller includes an interlock network connected to transfer the humidity input signal to the conditioning channel and a switch means controlled by the auxiliary output of the temperature controller.