A smoke damper is a motorized or automatic closure device installed in ductwork to prevent smoke and hot gases from traveling through HVAC systems during a fire. These dampers are required by building codes in commercial buildings and are typically rated for temperatures up to 350°F. Smoke dampers automatically close when triggered by a fusible link that melts at approximately 165°F or by an electronic control signal.
Fire Safety Standards
Smoke dampers must meet UL 555S standards and are commonly installed in return air plenums, supply ducts, and interconnecting ductwork. They provide critical barriers that compartmentalize fire zones and prevent rapid smoke migration through multi-floor buildings. Many dampers are equipped with 24-volt actuators for integration with building fire alarm systems.
Installation Requirements
Smoke dampers require accessible locations for inspection and maintenance every 4 years. They must be installed with proper sealing to prevent air bypass around the damper blade. Building codes typically mandate smoke dampers in all penetrations through fire-rated walls and in smoke control systems serving multiple floor levels.