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 cutoff fully, and propelling the vehicle. As the steam is expelled from cylinders out into the atmosphere through the chimney, with every gear cycle, it creates a vacuum in the firebox, drawing in fresh air.

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」。

The blower is usually operated by a valve. When open, it releases some steam from the boiler to the chimney. This creates vacuum in the firebox, drawing in fresh air. However, since this airflow is vastly inferior to the acceleration airflow, the blower is only efficient when used on a stationary engine.

The damper is usually operated by a lever. When closed (pushed down) it chokes the airflow, drastically reducing fire temperature, even if the vehicle is accelerating. This is used to intentionally cut steam production when it is no longer needed, although doing so with a well-timed water injection is an even more efficient alternative.