Conditioned air distribution system

In an air distribution system for supplying conditioned air to at least one zone to be conditioned, the combination of:

• a supply duct connected with a source of conditioned air under pressure and having an air outlet communicating with the zone;
• a valve in said duct movable in duct opening and closing directions;
• a control for said valve including a fluidic signal comparison and amplifying means, a fluid power supply conduit for the fluidic amplifying means connected with said duct, a thermostat providing a temperature responsive fluidic signal to said comparison and amplifying means, means providing a duct pressure signal to said comparison means, a valve actuator connected to the valve in the duct and operated by the comparison and amplifying means, said actuator being connected with said valve for movement of the valve in said duct opening and closing directions;
• secondary conditioning means for further conditioning the air before it is introduced into the zone from the duct;
• and
• secondary conditioning fluidic control means operable in conjunction with and under control of said thermostat for regulating said secondary conditioning means.