Steam humidifiers used in air-conditioning plants are divided into two groups: steam producers or users using existing steam. If sufficient amount of steam is present in the room to be air-conditioned, the water in the steam is separated and the moisture is removed by spraying the air in the form of dry vapor. With a 2-way motorized valve mounted on the steam spray nozzle, the desired relative humidity level is controlled in a proportional and / or positional manner. The size of steam humidifiers