Which device is typically used to humidify air by injecting steam into the airflow in the supply duct?

Which device is typically used to humidify air by injecting steam into the airflow in the supply duct?

• A. Steam jets
• B. Drum-type humidifier
• C. Flow-through humidifier
• D. Mist sprayer

Answer: (A)

Injecting steam directly into the supply air is done with a steam jet humidifier. It draws saturated steam from the boiler and releases it through a high‑velocity nozzle into the moving duct air. The steam rapidly blends with the stream, condenses, and raises the humidity quickly, giving precise control and fast response. This method also minimizes duct wetting and is well-suited for large spaces or tight humidity targets. Other options rely on evaporating water from wetted surfaces or spraying water as a mist, which are slower to respond or can cause moisture issues in the duct; they do not inject steam into the airflow in the same direct, controlled way.

Injecting steam directly into the supply air is done with a steam jet humidifier. It draws saturated steam from the boiler and releases it through a high‑velocity nozzle into the moving duct air. The steam rapidly blends with the stream, condenses, and raises the humidity quickly, giving precise control and fast response. This method also minimizes duct wetting and is well-suited for large spaces or tight humidity targets. Other options rely on evaporating water from wetted surfaces or spraying water as a mist, which are slower to respond or can cause moisture issues in the duct; they do not inject steam into the airflow in the same direct, controlled way.