These devices are centrifugal duct humidifiers, they haven't fan and use the air flow of the pipeline to increase and distribute the humidity. These devices are very simple but effective, economical, with reduced maintenance costs and operation. For their installation is necessary to establish a system for drainage of condensation water and for the not pulverized water that falls from the unit, and a drop separator. Their capacity can be adjusted simply by changing the quantity of water supply. They work with drinkable water from municipal network (not demineralized).

They are used in air conditioning systems in the textile industry or in air-handling units.