Model RD-521-BT

1 Hour - Ceiling Radiation Damper
R-6.3 Insulated Outlet Box - Butterfly Style Blade

The RD-521-BT ceiling radiation damper employs butterfly style blades for point-of-origin control of radiant heat in HVAC systems. The RD-521-BT is installed horizontally in the ceiling membrane of combustible and non-combustible assemblies with fire resistance ratings up to and including 1 hour.

Standard Construction

Frame: 30 ga. (0.40) galvanized steel outlet box with 1-1/2" (38) thick fiberglass R-6.3 insulation.
Blades: 22 ga. (0.85) galvanized steel - butterfly.
Plaster Ground: 5/8" (16) deep x 1" (25) wide.
Fire Closure Device: Fusible Link.
Fire Closure Temperature: 165^oF (75^oC).
Minimum Size: Grille Opening - 4" x 4" (102 x 102), Duct - 4" Ø (102 Ø)
Maximum Size: Grille Opening - Square: 12" x 12" (305 x 305)
                                                      Rectangular: 24" (610) W or 24" (610) H
                                                      with a maximum area of 144 in². (929 cm²)
                                                      Duct - 10"Ø (254 Ø)                              

Ratings

UL 555C Fire Resistance Rating: 1 hour (horizontal, for use in UL assemblies
L-521, L-546, L-574, L-576, L-581, L-583, L-585, P-522, P-545 and P-547).

Thermal Resistance: R-6.3 or 8.0

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