Humidifying apparatus includes a body comprising a chamber into which water is supplied by a water tank. An air flow is generated over water stored in the chamber, and a humidifying system humidifies the air flow with water from the chamber. Water in the chamber is irradiated by an ultraviolet radiation emitting lamp. The lamp forms part of a cartridge removably locatable within the body so that the lamp is received within an ultraviolet radiation transparent tube of the chamber. The body includes a plurality of supports for supporting the cartridge therebetween. Each support has a curved track for guiding movement of the cartridge towards the tube, the tracks being shaped to orient the cartridge for insertion of the lamp into the tube as the cartridge moves along the tracks towards the tube.