An aircraft air conditioning system comprising an ambient air line, for ambient air to flow through, connected to supply ambient air to a mixer of the aircraft air conditioning system. An ambient air compressor is arranged in the ambient air line for compressing the ambient air flowing there through. A refrigerating apparatus comprises a refrigerant circuit for a refrigerant to flow through, including a refrigerant compressor arranged in the refrigerant circuit. The refrigerant circuit is coupled thermally to the ambient air line to transfer heat from the ambient air to the refrigerant before the ambient air is supplied to the mixer. A cabin exhaust air turbine is connected to a cabin exhaust air line, is coupled to the ambient air compressor arranged in the ambient air line, and is configured to expand the cabin exhaust air flowing through the cabin exhaust air line and to drive the ambient air compressor.

An air supply system comprising at least two bleed sources configured to provide bleed air, wherein each bleed source comprises an engine or an auxiliary power unit and an oil as lubricant for the engine or the auxiliary power unit. The system also includes at least one air conditioning pack for cooling the bleed air from the bleed sources, and a plurality of bleed ducts, wherein each bleed duct connects one of the bleed sources to the at least one air conditioning pack. The system further comprises a plurality of detectors, wherein each detector is associated with a bleed source and the plurality of detectors are configured for detecting substances specific for the oil.

An engine driven environmental control system (ECS) air circuit includes a gas turbine engine having a compressor section. The compressor section includes a plurality of compressor bleeds. A selection valve selectively connects each of said bleeds to an input of an intercooler. A second valve is configured to selectively connect an output of said intercooler to at least one auxiliary compressor. The output of each of the at least one auxiliary compressors is connected to an ECS air input.

An aircraft includes a fuselage defining a cabin region and a crown region. The aircraft also includes a duct disposed within the fuselage. The duct is coupled to one or more drying air vents disposed in the crown region and coupled to one or more cabin vents disposed with the cabin region. The one or more drying air vents are configured to output drying air, received via the duct, into the crown region, and the one or more cabin vents are configured to output conditioned air, received via the duct, into the cabin region. The aircraft further includes one or more valves coupled to the duct and configured to, in a first valve position, route airflow within the duct to the one or more drying air vents and configured to, in a second valve position, route the airflow within the duct to the one or more cabin vents.

A microtube heat exchanger is disclosed, including two end plates with an array of holes or openings and an array of microtubes disposed in the array of openings between the two end plates. The heat exchanger can be used in environmental control systems, including systems for aerospace applications.

An example temperature sensing device includes an air distribution inlet through which primary air is blown into via an environmental control system, a cabin air inlet through which secondary air enters from a passenger area of a fuselage and the cabin air inlet is coupled to the air distribution inlet through a duct and the secondary air is passively drawn into the cabin air inlet and to the duct due to a pressure difference present in the duct, and a temperature sensor coupled to the duct and positioned downstream of the cabin air inlet along an airflow path of the secondary air so as to be exposed to the secondary air drawn in through the cabin air inlet and flowing through the duct.

An air cycle machine is provided. The air cycle machine can be included an environmental control system of an aircraft. The air cycle machine can include a turbine comprising a plurality of inlet gas flow paths, a compressor driven by the turbine from a shaft, and a fan driven by the turbine from the shaft.

The disclosure describes a system that includes an auxiliary power unit (APU), an APU throttle valve, and an environmental control system (ECS) bypass valve. The APU is configured to receive cabin discharge air from an aircraft cabin and receive ECS supply air from an air pressurization system (APS). The APU throttle valve is configured to control flow of cabin discharge air from the cabin to the APU. The ECS bypass valve configured to control flow of ECS supply air from the APS to the APU.

An airplane is provided. The airplane includes a pressurized medium, a turbine, and a valve. The turbine includes at least one nozzle. The valve is located upstream of the turbine. The valve provides the pressurized medium to the at least one nozzle of the turbine according to an operational mode.

An architecture for an aircraft comprises two air-conditioning systems, two converters, each intended to supply one of the air-conditioning systems, and at least one first electric machine which starts up a first main engine of the aircraft. The electrical architecture is configured such that the two converters can together supply the first electric machine. A method of operating the architecture is also provided.