Greenheck’s HBT-221 rectangular bubble-tight damper is now available in sizes up to 48 x 52 inches. This allows larger openings to be filled with one pre-engineered damper to provide zero leakage rather than a multi-section assembly that can add a significant amount of pressure to the system. In addition, larger-size dampers can be configured with a single actuator versus two actuators found in multi-section damper assemblies. The HBT-221 features a blade seal mechanically fastened to the blade that is field replaceable and a flanged damper frame for easy mounting. It’s available with a full range of electric, pneumatic, or manual actuator options. Each damper unit is factory-tested to ensure bubble-tight leakage performance per AMCA 500-D up to 10 inches of water column and meets ASME AG-1, Class 0A requirements.