US Patent 7096684 Air conditioner

A humidity control device includes a first adsorption element (81) and a second adsorption element (82). A first filter (301) is provided under the first adsorption element (81), while a second filter (302) is provided under the second adsorption element (82). The humidity control device performs first operation and second operation alternately. Directions of air flowing through the respective filters (301, 302) are reversed between the first operation and the second operation. Reversal of the direction of the air flowing through each filter (301, 302) removes dust and the like from each filter (301, 302).