A flow generator (4) for generating a flow of pressurized breathable gas includes a cylindrical housing (24,34) and a motor (44) supported in the housing (24,34). The motor (44) has a shaft (45) having a first end and a second end opposite the first end. The shaft (45) is generally coincident with an axis of the motor (44). A first impeller (36) is attached to the first end of the shaft (45) and a second impeller (42) is attached to the second end of the shaft (45). A stator (38) directs an air flow (F) from the first impeller (36) back towards the motor axis. The housing (24,34) includes an inlet (26) adjacent the first end of the shaft (45) having an inlet axis generally coincident with the motor axis and at least one outlet (28,30) between the first and second impellers (36,42). The at least one outlet (28,30) has an outlet axis generally tangential to the motor axis.
