The 2015 International Mechanical (IMC) and Building (IBC) Codes provided new and clear guidance for ceiling radiation dampers (CRDs) that affect architects, engineers, specifiers, contractors, and building inspectors. If not recognized and addressed from the beginning of a project, these code revisions could result in confusion, design changes, delays, and costly rework for project managers and other stakeholders.
Since the early part of the 20th century, ceiling designs tested by third-party testing agencies, such as Underwriters Laboratories (UL), have been performed in static airflow conditions. Static air flow condition means that the ceiling (with one or more ceiling dampers installed) is exposed to a controlled fire, however no air movement through the ceiling damper(s) is ever imposed. The test standard for which ceiling radiation dampers are tested and classified to is UL555C. The controlled fire exposure is based upon UL263 (ASTM E119).