Quick Reference Rectangular Industrial Dampers Quick Reference System Rectangular Dampers – Round Commercial Dampers – Rectangular Industrial Dampers – Louvers – Balancing & Regulating Dampers Rectangular Industrial Dampers Model Frame Depth Blade Style Max. Pressure (W.G.) Max. Velocity (FPM) Operator Stainless Option Submittal Revit H-420 8" 3-V / Opposed 10 4,000 Manual, Electric, or Pneumatic YES H-421 8" 3-V / Parallel 10 4,000 Manual, Electric, or Pneumatic YES AH-620 8" Airfoil / Opposed 13 6,000 Manual, Electric, or Pneumatic YES (Frame only) AH-621 8" Airfoil / Parallel 13 6,000 Manual, Electric, or Pneumatic YES (Frame only) H-620 8" 3-V / Opposed 21 6,000 Manual, Electric, or Pneumatic YES H-621 8" 3-V / Parallel 21 6,000 Manual, Electric, or Pneumatic YES NAH-720-1 8" Airfoil / Opposed 20 4,500 Manual, Electric, or Pneumatic YES NAH-721-1 8" Airfoil / Parallel 20 4,500 Manual, Electric, or Pneumatic YES NAH-720-2 8" Airfoil / Opposed 30 6,000 Manual, Electric, or Pneumatic YES NAH-721-2 8" Airfoil / Parallel 30 6,000 Manual, Electric, or Pneumatic YES NAH-720-3 8" Airfoil / Opposed 35 6,000 Manual, Electric, or Pneumatic YES NAH-721-3 8" Airfoil / Parallel 35 6,000 Manual, Electric, or Pneumatic YES NAH-720-4 8" Airfoil / Opposed 40 8,000 Manual, Electric, or Pneumatic YES NAH--721-4 8" Airfoil / Parallel 40 8,000 Manual, Electric, or Pneumatic YES
