Abstract: A tub is configured to contain a supply of water and be inserted into a chamber of a humidifier. The tub includes a tub base configured to contain a supply of water and a tub lid connected to the tub base. The tub lid includes an inlet configured to receive a flow of breathable gas to be humidified and an outlet for the humidified flow of breathable gas. The tub further includes a water level indicator configured to indicate a level of the supply of water in the tub base. The water level indicator includes an inclined portion configured to direct the flow of breathable gas from the inlet away from the outlet. The water level indicator may be visible through the inlet.

Abstract: A humidifier (14) for humidifying a flow of breathable gas to be delivered to a patient includes a chamber (16) configured to receive the flow of breathable gas; a tub (20) configured to contain a supply of water, the tub being configured to be inserted into the chamber; a lid (18) provided on the chamber and being movable between an open position and a closed position; and a seal (19) provided on the lid, the seal being configured to seal the chamber such that the flow of breathable gas pressurizes the chamber. The humidifier may be connectable to a flow generator (12) configured to generate the flow of breathable gas. A tube for delivering the humidified flow may be connected to the humidifier. The tube may be a heated or non-heated tube. A respiratory apparatus for delivering a flow of breathable gas to a patient may include the humidifier and the flow generator and/or the tube.