Humidifier system for artificial respiration

A humidifier system for heating and humidifying respiratory gases, comprising:

• a housing having opposite first and second ends and a chamber between said ends defining a flow path for respiratory gases, a first port at the first end for connection to a ventilator breathing circuit and a second port at the second end for connection to a patient to supply respiratory gases to the patient and to receive exhaled gases from the patient;
• a body of heat moisture exchange (HME) material within the chamber, the HME material comprising a material which can retain moisture and heat;
• a water permeable device within the chamber, the housing having a water refill inlet communicating with the water permeable device;
• a water supply outside the housing connected to the water refill inlet to supply water to the water permeable device;
• and
• a heater mounted outside the housing for heating the housing and maintaining the housing at a predetermined temperature.