Greenheck’s new ceiling radiation damper model CRD-320WT, combined with select models of Greenheck ceiling exhaust bathroom fans, adds even more code-compliant options for wood truss applications. The CRD-320WT damper is UL approved for use in 20 different, one-hour combustible, UL rated ceiling/floor assemblies. The damper can be factory-mounted to one of seven Greenheck SP-B ceiling exhaust fans (size 50 to 200 cfm) or two low-profile SP-L fans (size 50 to 80 cfm) when required in a ceiling installation.