Product details

SKU: 1892765144
This durable two-sided plastic sizing wheel comes with a complete instruction manual for residential and commercial duct-sizing procedures.


  • Sizes metal ducts, lined metal ducts duct board airways, and wire helix flexible ducts.
  • Converts round shapes to equivalent rectangles.
  • Correlates available pressure with total effective length and friction rate (Manual D sizing calculations).
  • Converts velocity into velocity pressure and vice versa.
  • Corrects for altitude and temperature