Humidifier

A humidification chamber for a respiratory therapy system, the humidification chamber being configured to hold a humidifying fluid in a humidifying fluid reservoir, and comprising:

• a base, a top wall, and an outer side wall extending between the base and the top wall;
• an inner side wall spaced at a distance from the outer side wall to form a wall cavity between the inner side wall and the outer side wall, the wall cavity defining a gas flow path that is around an outside of the humidifying fluid reservoir, an interior surface of the inner side wall defining an outer perimeter of the humidifying fluid reservoir;
• a guide extending from the inner side wall to the outer side wall across the wall cavity, the guide defining an insulating channel through the wall cavity;
• a chamber inlet for receiving breathing gas, the chamber inlet comprising an opening into the wall cavity;
• a humidifying fluid reservoir inlet, the humidifying fluid reservoir inlet providing a path for gas to flow from the wall cavity to the humidifying fluid reservoir after passing over a surface of the humidifying fluid;
• and
• a delivery outlet for delivering breathing gas from the humidifying fluid reservoir externally of the humidification chamber,
• wherein the insulating channel, the humidifying fluid reservoir inlet, and the humidifying fluid reservoir provide a chamber gas flow path that extends between the chamber inlet and the delivery outlet such that flow passes from the chamber inlet to the insulating channel to the humidifying fluid reservoir to the delivery outlet.