Model RD-521-NP-G

1 Hour - Ceiling Radiation Damper
Field Installed Outlet Box - Butterfly Style Blade

The RD-521-NP-G ceiling radiation damper employs butterfly style blades for point-of-origin control of radiant heat in HVAC systems. The RD-521-NP-G 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-G must have a field assembled outlet box installed in 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 (737 cm²)
Transition: None (field adapation 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 (horizontal, for use in UL assemblies L-521, L-528, L-546, L-558, L-562, L-574, L-576, L-581, L-583, L-585, M-509, M-540 and in roof/ceiling designs P-522, P-533, P-538, P-545, P-547, P-579 and P-580.
Thermal Resistance: R-6.5 or 8.7

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