A backdraft damper permits the move in one way and won't alter the direction or lessen the flow. In the meantime, the balancing damper utilizes rotating shutters to control airflow and speed. Depart a Reply Manual dampers are altered by hand and are typically used in more mature HVAC units. https://fernandouofui.blog-kids.com/36774116/the-definitive-guide-to-air-control-dampers-for-hot-climates