that has been wicked from the cavity the resulting vapor is discharged through an exhaust grill above the cavity application_number US 84967001 A description a humidifier 100 according to the preferred embodiment of the invention is shown in fig1 though 10 a humidification unit 112 and a liquid supply tank 113 are each removably mounted side by side on a base 114 formed into the upper surface 117 of the base is a reservoir 120 that includes a evaporation cavity 122 also included in the reservoir is a liquid supply channel 123 communicating with the evaporation cavity 122 and is an inlet cavity 125 located under the supply tank 113 a valve actuator stem 126 projects upwardly from within the inlet cavity pivotally mounted on the base is a latch member 128 for securing the supply tank 113 to the base the humidification unit 112 includes a horizontal wall 131 within an enclosure 132 the horizontal wall and side walls 133 of the enclosure cooperate with the evaporation cavity 122 of the base 114 to define an evaporation chamber 135 extending downwardly within the chamber from the horizontal wall is a heating element 136 that projects into the evaporation cavity 122 of the base 114 a porous fibre wicking sleeve 137 surrounds the heating element and is adapted to draw water by capillary action from the evaporation cavity to the surface 139 of the heating element the sleeve is constructed of an absorbent fabric material such as flame retardent polyester fiber which has the ability to wick water from the cavity rapidly and which is not easily flammable and tolerant to high temperatures the sleeve is removable from the heating element which allows physical access to the heating element.