A humidifier for direct low pressure injection of steam into a duct. A source of steam is provided, and a steam tube is in fluid communication with the source of steam. A distal end segment of the steam tube is inclined with respect to the horizontal when the system is mounted to a duct to cause condensation within the steam tube to drain back to the source of steam under the force of gravity. The distal end of the steam tube includes an opening having a lip on an inside surface of the opening, where the lip directs condensation formed at the opening to flow back into the steam tube and back to the source of steam.