Apparatus and methods for providing humidity in respiratory therapy

Apparatus for providing positive airway pressure for the treatment of sleep apnea, chronic pulmonary obstruction and snoring, the apparatus comprising:

• a flow generator configured to provide air at a pressure of 4-20 cm of water at an outlet;
• a user interface comprising support bands configured to retain the user interface on the head of a user, an interface passage in fluid communication with the flow generator outlet and having a lumen, and a mask having a chamber and connected to the interface passage so that pressurized air may be delivered from the lumen into the chamber of the mask, the mask being configured to be positioned in communication with an airway of the user to provide a generally sealed connection to the user for the delivery of the pressurized air for inhalation, the interface passage having at least one vent therein;
• at least one vent valve associated with the at least one vent;
• and
• a humidifier configured to introduce water into the interface passage at a position distal to both the flow generator and the at least one vent, the at least one vent valve substantially in a substantially closed position in the presence of a low pressure condition and in a open position during the presence of a high pressure condition.