US Patent 8006962 Humidifier with louvered air intake

A humidification system includes a housing mountable into an air duct, that includes a base frame, a cover and at least one open end panel. The base frame is mountable to an opening in the air duct that is shaped and configured to align with the base frame. The cover attaches to the base frame with the open end panel between the base frame and cover. The air outlet is through the open end panel. An evaporative element is positioned between the air inlet and air outlet. Controlling humidity output provides moisture to the evaporative element when needed. The bypass frame includes louvers that are positioned within the air inlet, where the louvers are sized to extend into the air duct. The louvers are graduated in size. After passing through the housing, an air return directs humidified air from the open end panel to a low pressure air duct.