Humidifiers for respiratory apparatus

A positive airway device is configured to deliver a pressurized flow of humidified respiratory gas to a patient's airways and includes a flow generator with a blower portion and a docking portion laterally adjacent to the blower portion. The docking portion is separated from the blower portion by a divider and comprises a cavity configured to laterally receive a humidifier tub. The humidifier tub comprises a first tub subsection with an air inlet opening and an air outlet opening and a second tub subsection. A flange extending outwardly from an outer surface of the humidifier tub forms a transition between the first and second tub subsections. The humidifier tub is configured so that when the humidifier tub is fully received by the docking portion, the first tub subsection is enclosed within the cavity and the second tub subsection remains outside the cavity.