In this Condenser article, we look at the simple yet effective design of the curtain blade fire damper. Learn how these life safety dampers work with the MCDLG Newsstand.
Curtain fire dampers perform the same function as any fire damper. These life safety dampers are installed in the penetrations of fire barriers to block the passage of flames through the barrier penetration. Unlike the multi-blade fire dampers, curtain blade fire dampers use a unique and simple design to get the job done. Simple, yet effective.
Curtain fire dampers are equipped with a single accordion-style damper blade mounted at the top of the damper frame and suspended by a fusible link. The curtain blade is a series of metal slats linked together into a curtain. During standard operation, the curtain blade is folded into a stack and kept out of the air stream. The frame can be square, rectangular, or round; although round curtain dampers will have the curtain blades at the center of the damper.
The fusible link holds the curtain black stack in place, until the blade needs to be deployed. Every fusible link will have a temperature threshold, which is typically 165°F or 212°F. The fusible link is designed to break apart when temperatures around the damper reach the rated threshold. Once the link is broken, the blade stack is released. When the damper is vertically mounted, the curtain blade will slide down the frame via gravity.
The fusible link holds the curtain blade stack in place, until temperatures in the duct reach a predetermined threshold.
When the damper is horizontal, or rated for dynamic air conditions, the curtain blade will be spring loaded to assist transit across the damper opening. Once the curtain blade reaches the other side of the frame, the bottom section of the blade will be locked in place by locking mechanisms. This feature keeps the curtain blade in place during an emergency. Once closed and locked, the damper must be manually reopened by an operator.
All fire dampers will be rated for either static or dynamic air conditions. This refers to whether system fans are designed to power down during an emergency. Dynamic dampers are rated to close against airflow, so they will close even when system fans are still running. Static dampers can only close during still air conditions and require that fans be off. When choosing fire dampers, determine whether your fan system will shut off or stay on during an emergency. This will help you decide on static or dynamic dampers.
The simple yet effective design of the curtain fire damper makes it a cost-efficient option for meeting fire safety requirements. Curtain fire dampers are available from manufacturers, typically rated for static or dynamic air conditions and for fire resistance ratings of 1½ or 3 hours.
Here are some examples of curtain fire dampers from Air Balance:
The D19 Dynamic Curtain Fire Damper
- Rated for dynamic air conditions and a 1.5-hour fire resistance rating
- Available with a 3-hour rating as the D39 dynamic curtain fire damper*
- Maximum air velocity of 4000 fpm, max pressure of 8 in. w.g.**
- Available with a thin line frame as the D19F, or an integrated sleeve as the D19X
- Maximum assembly sizes up to 120” x 24” or 24” x 120”***
The 119 Static Curtain Fire Damper
- Rated for static air conditions and a 1.5-hour fire resistance rating
- Available for vertical and horizontal mounting.
- Available with a thin line frame as the 119F, or an integrated sleeve as the 119X
- Maximum assembly sizes up to 120” x 120” vertical or 102” x 48” horizontal
Consider a balanced approach to your next project with Air Balance. They offer a wide range of life safety dampers, as well as standard control and balancing dampers. Meet your project’s requirements with MCDLG brands.
*Sizing options will differ between the 1.5-hour and the 3-hour rated models. Please consult the submittal for sizing details.
**Max velocity and max pressure will differ by single panel size. Multi-panel assemblies are not available at certain max velocities and pressures. Review the product submittal for sizing details.
***Max assembly size will differ by max velocity, max pressure, and sleeve type. Multi-panel assemblies are not available at certain max velocities and pressures. Review the product submittal for sizing details.
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