Humidifier with a water tub within a pressurized chamber

A tub for humidifying a flow of breathable air to be delivered to a patient, the tub comprising:

• a tub base configured to contain a supply of water;
• an inlet to receive the flow of breathable air;
• a tub lid detachably connected to the tub base;
• and
• a flow plate assembly detachably connected to the tub base, the flow plate assembly including a flow plate having a perimeter, the perimeter including a tub seal, the flow plate forming part of a pathway for the pressurized air to be delivered, in use, to the tub base,
• wherein the flow plate has an inner plate portion positioned between the tub base and the tub lid, the inner plate portion extending inwardly relative to the perimeter to a substantially central portion of the tub where, the inner plate portion forming the part of the pathway, and
• wherein the inner plate portion comprises a plastic material that forms the part of the pathway, and the tub seal comprises elastic material, and
• wherein the perimeter of the flow plate assembly includes a frame with a horizontal portion and a vertical wall of the plastic material projecting below the horizontal portion, the vertical wall comprising a wedge radially outwards when the tub is assembled.

A tub for humidifying a flow of breathable air to be delivered to a patient, the tub comprising:

• a tub base configured to contain a supply of water;
• a channel configured to receive the flow of breathable air from a flow generator;
• an inlet to receive the flow of breathable air from the channel;
• a tub lid connected to the tub base;
• and
• a flow plate connected to the tub base, the flow plate including a perimeter portion extending inwardly beyond an inner perimeter of the tub, the flow plate including plastic material, the flow plate forming part of a pathway for the breathable air to be delivered, in use, from the channel to the tub base, the flow plate having a horizontal surface configured to seal with the tub lid when the tub lid is closed relative to the tub base, the flow plate having a vertical portion extending transverse to the horizontal surface, the vertical portion being configured to seal with the tub base and being spaced inwardly from an edge of the horizontal surface.