Abstract: Methods of recirculating clean air in an atmosphere of an enclosure comprise directing an input air stream from the atmosphere of the enclosure through a coiled duct at a rate sufficient to stratify the input air stream within the coiled duct according to a molecular weight of components of the input air stream and to form a heavy fraction stream and a light fraction stream, wherein the heavy fraction stream is relatively enriched in carbon dioxide as compared to the light fraction stream; withdrawing the heavy fraction stream from the coiled duct; and returning the light fraction stream from the coiled duct to the atmosphere of the enclosure.

Abstract: Methods of recirculating clean air in an atmosphere of an enclosure comprise directing an input air stream from the atmosphere of the enclosure through a coiled duct at a rate sufficient to stratify the input air stream within the coiled duct according to a molecular weight of components of the input air stream and to form a heavy fraction stream and a light fraction stream, wherein the heavy fraction stream is relatively enriched in carbon dioxide as compared to the light fraction stream; withdrawing the heavy fraction stream from the coiled duct; and returning the light fraction stream from the coiled duct to the atmosphere of the enclosure.

Abstract: Centrifugal air separators, systems including the same, and methods of separating gas are disclosed. Centrifugal air separators include a separation section configured to separate an input air stream into a clean air stream emitted from an exit port of the separation section and a waste stream emitted from a waste port of the separation section. The separation section includes a coiled duct and is configured to transmit through a duct entrance port a duct input air stream that is at least a portion of the input air stream and to at least partially separate the duct input air stream according to a molecular weight of gaseous components of the duct input air stream into a duct clean air stream that is at least a portion of the clean air stream and a duct waste stream that is at least a portion of the waste stream.

Abstract: Centrifugal air separators, systems including the same, and methods of separating gas are disclosed. Centrifugal air separators include a separation section configured to separate an input air stream into a clean air stream emitted from an exit port of the separation section and a waste stream emitted from a waste port of the separation section. The separation section includes a coiled duct and is configured to transmit through a duct entrance port a duct input air stream that is at least a portion of the input air stream and to at least partially separate the duct input air stream according to a molecular weight of gaseous components of the duct input air stream into a duct clean air stream that is at least a portion of the clean air stream and a duct waste stream that is at least a portion of the waste stream.

Abstract: Centrifugal air separators, systems including the same, and methods of separating gas are disclosed. Centrifugal air separators include a separation section configured to separate an input air stream into a clean air stream emitted from an exit port of the separation section and a waste stream emitted from a waste port of the separation section. The separation section includes a coiled duct and is configured to transmit through a duct entrance port a duct input air stream that is at least a portion of the input air stream and to at least partially separate the duct input air stream according to a molecular weight of components of the duct input air stream into a duct clean air stream that is at least a portion of the clean air stream and a duct waste stream that is at least a portion of the waste stream.

Abstract: Centrifugal air separators, systems including the same, and methods of separating gas are disclosed. Centrifugal air separators include a separation section configured to separate an input air stream into a clean air stream emitted from an exit port of the separation section and a waste stream emitted from a waste port of the separation section. The separation section includes a coiled duct and is configured to transmit through a duct entrance port a duct input air stream that is at least a portion of the input air stream and to at least partially separate the duct input air stream according to a molecular weight of components of the duct input air stream into a duct clean air stream that is at least a portion of the clean air stream and a duct waste stream that is at least a portion of the waste stream.