An aircraft comprising: (a) a fuselage comprising a passenger area having an occupancy zone comprising locations for seating passengers and a recirculation zone comprising an aisle; (b) a floor distribution section coupled in flow communication to said occupancy zone and said recirculation zone, an upper floor and a lower floor defining a location for the floor distribution section; (c) an air supply system coupled to said aircraft, said air supply system comprising: • an air external supply device coupled to said fuselage and configured to receive external air mass from exterior of aircraft; • a supply duct coupled in flow communication to said air supply device; and • an air supply outlet coupled in flow communication to said supply duct and coupled to the upper floor and in flow communication with said occupancy zone, the air supply outlet being configured to discharge external air mass into the occupancy zone, and (d) an air recirculation system coupled to said aircraft, said air recirculation system comprising: • a recirculation supply device coupled to said fuselage; • a recirculation duct coupled in flow communication to said recirculated supply device and coupled to said floor distribution section; and • • a recirculation outlet coupled in flow communication to said recirculation duct and in flow communication with said recirculation zone and said floor distribution section, the recirculation outlet comprising a diffuser configured to discharge recirculated air from the floor distribution section into the recirculation zone. (a) a fuselage comprising a passenger area having an occupancy zone comprising locations for seating passengers and a recirculation zone comprising an aisle; (b) a floor distribution section coupled in flow communication to said occupancy zone and said recirculation zone, an upper floor and a lower floor defining a location for the floor distribution section; (c) an air supply system coupled to said aircraft, said air supply system comprising: • an air external supply device coupled to said fuselage and configured to receive external air mass from exterior of aircraft; • a supply duct coupled in flow communication to said air supply device; and • an air supply outlet coupled in flow communication to said supply duct and coupled to the upper floor and in flow communication with said occupancy zone, the air supply outlet being configured to discharge external air mass into the occupancy zone, and • an air external supply device coupled to said fuselage and configured to receive external air mass from exterior of aircraft; • a supply duct coupled in flow communication to said air supply device; and • an air supply outlet coupled in flow communication to said supply duct and coupled to the upper floor and in flow communication with said occupancy zone, the air supply outlet being configured to discharge external air mass into the occupancy zone, and (d) an air recirculation system coupled to said aircraft, said air recirculation system comprising: • a recirculation supply device coupled to said fuselage; • a recirculation duct coupled in flow communication to said recirculated supply device and coupled to said floor distribution section; and • • a recirculation outlet coupled in flow communication to said recirculation duct and in flow communication with said recirculation zone and said floor distribution section, the recirculation outlet comprising a diffuser configured to discharge recirculated air from the floor distribution section into the recirculation zone. • a recirculation supply device coupled to said fuselage; • a recirculation duct coupled in flow communication to said recirculated supply device and coupled to said floor distribution section; and • • a recirculation outlet coupled in flow communication to said recirculation duct and in flow communication with said recirculation zone and said floor distribution section, the recirculation outlet comprising a diffuser configured to discharge recirculated air from the floor distribution section into the recirculation zone.