A passenger cabin air distribution system includes a ventilation system and an ejector-diffuser. The ventilation system is operable to provide a conditioned air. The ejector-diffuser is positioned to receive a flow of the conditioned air from the ventilation system. The ejector-diffuser includes an induction unit and a diffuser section. The induction unit includes a secondary inlet in communication with a cabin air from a passenger cabin and is configured to mix the flow of the conditioned air with an induced flow of the cabin air into a mixed air. The diffuser section includes a discharge to eject the mixed air to the passenger cabin. The diffuser section is shaped to provide for efficient mixing with low backpressure in order to maintain the low motive pressure in the nozzle.

An exhaust fan unit of a heating, ventilation, and/or air conditioning (HVAC) system includes an outer fluid path of a nozzle assembly of the exhaust fan unit defined by and between an outer wall of the nozzle assembly and an inner wall of the nozzle assembly, an inner fluid path of the nozzle assembly defined by and radially inward from the inner wall, and a plurality of entrainment ports extending from the outer wall to the inner wall and configured to enable environmental air to pass to the inner fluid path, where each entrainment port includes a bottom surface that tapers downwardly from the inner wall to the outer wall.

An air diffuser of a heating, ventilation, and/or air conditioning (HVAC) system includes a mixing chamber having a circulation inlet and a mixing region, a room air intake fluidly coupled with the circulation inlet and separated from the mixing region by a blank-off plate, and a nozzle. The nozzle is disposed adjacent to the circulation inlet and configured to accelerate a conditioned air flow into the mixing region such that unconditioned room air is induced by the conditioned air flow to enter the mixing region through the circulation inlet and from the room air intake.

An insert for an air intake of a suction duct, the insert including an inner portion configured to extend within the suction duct, a mating portion configured for sealingly engaging the air intake, and an outer portion configured for extending outside of the suction duct. The inner portion includes a conduit having a central axis extending along an inlet direction at the inlet end and along an outlet direction at the outlet end, the inlet and outlet directions being non-parallel. The outlet end has a smaller cross-sectional area than that of the suction duct. The insert includes an inlet in fluid communication with the inlet end of the conduit. The outer portion includes a curved lip surrounding at least part of an inlet opening of the inlet, the lip configured to direct a flow into the inlet opening and toward the inlet end of the conduit.

An exhaust fan unit of a heating, ventilation, and/or air conditioning (HVAC) system includes an outer fluid path of a nozzle assembly of the exhaust fan unit defined by and between an outer wall of the nozzle assembly and an inner wall of the nozzle assembly, an inner fluid path of the nozzle assembly defined by and radially inward from the inner wall, and a plurality of entrainment ports extending from the outer wall to the inner wall and configured to enable environmental air to pass to the inner fluid path, where each entrainment port includes a bottom surface that tapers downwardly from the inner wall to the outer wall.

A diffuser for a heating, ventilation, and air conditioning (HVAC) system includes a housing defining a plenum chamber, where the housing comprises a diffusion plate configured to direct a first air flow into the plenum chamber and to discharge a second air flow from the plenum chamber and a plenum plate disposed within the housing, where the plenum plate extends from a first side of the housing to a second side of the housing opposite the first side, and the plenum plate divides the plenum chamber into a first chamber and a second chamber. The diffuser includes a plurality of apertures disposed along the plenum plate, where the plurality of apertures is configured to direct a third air flow from the first chamber into the second chamber to draw the first air flow into the plenum chamber and to force the second air flow out of the plenum chamber.

A temperature control system in an aircraft passenger service unit is disclosed. In embodiments, the system includes a swirl chamber configured to receive an inlet air stream, and a vortex tube configured to receive the inlet air stream from the swirl chamber and separate the inlet air stream into a warmer air stream and a cooler air stream. In embodiments, the system further includes a nozzle configured to direct a temperature-controlled air stream into a passenger space of an aircraft; wherein the nozzle is configured to be selectably adjusted in order to selectively blend the warmer air stream and the cooler air stream in order to generate the temperature-controlled air stream.

A passenger cabin air distribution system includes a ventilation system and an ejector-diffuser. The ventilation system is operable to provide a conditioned air. The ejector-diffuser is positioned to receive a flow of the conditioned air from the ventilation system. The ejector-diffuser includes an induction unit and a diffuser section. The induction unit includes a secondary inlet in communication with a cabin air from a passenger cabin and is configured to mix the flow of the conditioned air with an induced flow of the cabin air into a mixed air. The diffuser section includes a discharge to eject the mixed air to the passenger cabin. The diffuser section is shaped to provide for efficient mixing with low backpressure in order to maintain the low motive pressure in the nozzle.

A temperature control system in an aircraft passenger service unit is disclosed. In embodiments, the system includes a swirl chamber configured to receive an inlet air stream, and a vortex tube configured to receive the inlet air stream from the swirl chamber and separate the inlet air stream into a warmer air stream and a cooler air stream. In embodiments, the system further includes a nozzle configured to direct a temperature-controlled air stream into a passenger space of an aircraft; wherein the nozzle is configured to be selectably adjusted in order to selectively blend the warmer air stream and the cooler air stream in order to generate the temperature-controlled air stream.

An insert for an air intake of a suction duct, the insert including an inner portion configured to extend within the suction duct, a mating portion configured for sealingly engaging the air intake, and an outer portion configured for extending outside of the suction duct. The inner portion includes a conduit having a central axis extending along an inlet direction at the inlet end and along an outlet direction at the outlet end, the inlet and outlet directions being non-parallel. The outlet end has a smaller cross-sectional area than that of the suction duct. The insert includes an inlet in fluid communication with the inlet end of the conduit. The outer portion includes a curved lip surrounding at least part of an inlet opening of the inlet, the lip configured to direct a flow into the inlet opening and toward the inlet end of the conduit.