A system for removing heat from electrical systems includes a dehumidification device including a desiccant, an evaporative cooling device, air moving devices, and an air flow control devices. The air moving device moves air through the dehumidification device, the evaporative cooling device, and the electrical systems. The air flow control device controls a rate of flow through the dehumidification device.

An air-cooled case enabling automatic setting of a flow of cooling air during natural cooling and during forced cooling contains a heating element and a cooling fan in a space surrounded by multiple surfaces that include a top surface and mutually facing side surfaces. The air-cooled case is provided with a top surface ventilation opening formed in the top surface, side surface ventilation openings formed in the side surfaces, and a shutter that is provided in the top surface ventilation opening and opens/closes the top surface ventilation opening.