Shaft Cross-Section and Damper Area Calculation in F300 Parking Smoke Exhaust System Design

These calculations must be performed for both the smoke exhaust shafts and the makeup air (fresh air) intake shafts, based on the required flow rates that have already been determined for each. According to the 2014 Fire Department Regulations, duct sizing calculations in all sections must be based on a maximum velocity of 12 m/s. With the velocity and the required flow rate known, the cross‑sectional area of the shafts can be calculated.

As a practical example, the schematic layout of the shafts and fan placement for the F300 parking smoke exhaust system—as designed and executed by our company in the Lotus Hotel project—is presented below. It should be noted that the shaft calculations were carried out based on the smoke exhaust and makeup air flow rates previously determined in the earlier sections.

Similarly, damper areas can be calculated based on the exhaust air flow rate and the air velocity through the damper face. As an example, a schematic layout of the dampers used in the Lotus Hotel project is also provided