Systems and methods for delivering a respiratory gas

A respiratory ventilation apparatus configured to deliver a respiratory gas to a patient interface, comprising a humidification assembly, the humidification assembly being configured to humidify the respiratory gas, the humidification assembly comprising:

• a liquid chamber configured to accommodate one or more liquids, the liquid chamber including a tank and a tank cover;
• wherein:
• the tank cover includes a humidification assembly gas inlet port, a humidification assembly gas outlet port, a first gas passage including an output port, and a second gas passage including an input port,
• the humidification assembly gas inlet port is configured to introduce the pressurized respiratory gas, via the first gas passage, into the tank,
• the humidification assembly gas outlet port is configured to introduce the humidified and pressurized respiratory gas, via the second gas passage back into a main body of the respiratory ventilation apparatus, and
• the tank cover further includes a shell and a bottom plate, and the bottom plate is connected with the shell to make the bottom plate and the shell form at least a portion of a surface of at least one of the first gas passage or the second gas passage.