送風器和火箱進氣口

空氣中的氧氣是火焰燃燒時不可或缺的；控制火箱的進氣量便能控制燃料的燃燒強度，間接調整火箱的溫度。

The primary way to feed air to the firebox is by opening the regulator and propelling the vehicle. As the steam is expelled from the boiler through steam chest and cylinders out into the atmosphere, fresh air is drawn to the firebox. This happens with every gear cycle, and the higher the cutoff setting the more the airflow.

此外，還有兩個裝置能用於調節火箱進氣量：「送風器」和「火箱進氣口」。

Blower is usually operated by a valve. When open, it releases steam from the boiler around the chimney area. This creates vacuum, pulling in air into the firebox. This is used when a vehicle is stationary. Having the blower open while accelerating is wasteful however, because the acceleration airflow is vastly superior to blower.

Damper is usually operated by a lever. When closed (pushed down) it chokes the airflow, drastically reducing fire temperature. This is used to intentionally cut steam production when it is no longer needed.