Abstract: A hospital room humidification system operated from an outside source of pressurized oxygen and/or other gas for increasing the humidity of the ambient air in the room. The humidification system includes a collapsible bag for containing a quantity of water in a condition sealed from the environment of the room, an atomizing nozzle formed with separate liquid and gas passageways, a first adapter for coupling the atomizing nozzle to the water containing bag, and a second adapter for selectively coupling the atomizing nozzle to the outside pressurized gas source. The atomizing nozzle is operable for causing the pressurized gas flow discharging from the air passageway to break the flow of liquid discharging from the liquid passageway into fine liquid particles and to directly dispense such particles into the air of the room in the form of a mist and in a manner which significantly increases the humidity of the ambient air in the room.