Heavy - marked by great psychological bodyweight; weighted down especially with unhappiness or difficulties or weariness; "a heavy coronary heart"; "a heavy routine"; "heavy information"; "a heavy silence"; "heavy eyelids" Design 1221G is often a higher general performance combination fire/smoke damper especially made for supply or return ducts that terminate https://johnathanbujxl.blogsmine.com/37391198/the-2-minute-rule-for-dampers-for-industrial-sector