Backdraft dampers: Put in to allow just one-way airflow, these types incorporate shafts on 1 close of every blade to avoid air from flowing back in the alternative course. If necessary, a counterbalance can support. Handbook dampers are modified by hand and are typically Utilized in more mature HVAC systems. https://aircontroldampersforengin67899.blogginaway.com/37318594/the-ultimate-guide-to-air-control-dampers-for-hot-climates