Model RD-521-NP

1 Hour - Ceiling Radiation Damper
Field Installed Insulated Duct Board Outlet Box - Ceiling Radiation Damper

The RD-521-NP ceiling radiation damper employs butterfly style blades for point-of-origin control of radiant heat in HVAC systems. The RD-521-NP is installed horizontally in the ceiling membrane of combustible floor-ceiling or roof-ceiling assemblies with fire resistance ratings up to and including 1 hour.The RD-521-NP must have a field assembled insulated duct board outlet box installed on it.

Standard Construction

Frame: 22 ga. (0.85) galvanized steel.
Blades: 22 ga. (0.85) galvanized steel - butterfly. Insulated with ceramic refractory material for dampers larger than 114 in.² (735 cm²)
Transition: None (field adaptation required.)
Plaster Ground: 5/8" (16) deep x 1" (25) wide.
Closure Device: Fusible Link.
Fire Closure Temperature: 165^oF (75^oC).
Minimum Size: 4" x 6" (102 x 152)
Maximum Size: Square: 16" x 16" (406 x 406)
                           Rectangular: 24" (610) W or 20" (508) H
                           with a maximum area of 256 in.² (1652 cm²).

Ratings

UL 555C Fire Resistance Rating: 1 hour (for installation in floor designs
L-521, L-528, L-546, L-558, L-562, L-574, L-576, P-581, P-583 and P-585
and in roof/ceiling designs P-522, P-533, P-538, P-545 and P-547).

UL 555C Listing: R14980
CSFM Listing: 3226-1404:100
Warnock Hersey Listing #: WHI-495-PSH-0177, -0178
Meets NFPA Standards: 90A and 101
Meets Building Code Standards: IBC, NBC, NFPA, SBC and UBC