💨 UL 555 / 555S Class I/II Leakage, 250°F/350°F Electric Spring Return Actuator

Fire Smoke Damper Actuator & CFM Calculator

Size combination fire smoke dampers (FSD) under UL 555 and UL 555S: calculate duct airflow velocity (2,000 to 4,000 FPM at 4.0 in WC static pressure), required 120V/24V high-temperature electric spring-return actuator torque (in-lbs based on damper square footage), Class I low-leakage seals, and sheet metal contractor margins.

1. Project & Operating Inputs

Total Fire Smoke Dampers Installed (Damper Units e.g. 42 Dampers)

Average Damper Face Area (Square Feet e.g. 8.0 Sq Ft / 24"x48")

Customer Bid Price for Supplied & Installed FSD Package ($ / Damper)

UL Rated FSD Damper, Belimo Fast-Acting Actuator, Wiring & Sheet Metal ($)

2. Financial Breakdown & Yield

UL 555 COMBINATION FSD ACTUATORS

Turnkey Damper Package Profit

HVAC Sheet Metal Margin

0.0%

Gross Revenue / Bill

Total Project CapEx

Operating / Material Cost