American Conditioning Contractors of America Auxiliary Calculations Duct Calculator. This durable two-sided plastic sizing wheel comes with a complete instruction manual for residential and commercial duct-sizing procedures. Designed by Hank Rutkowski.
Sizes metal ducts, lined metal ducts, duct board airways, and wire helix flexible ducts
Converts round shapes to equivalent rectangular shapes
Correlates available pressure with total effective length and friction rate (Manual D sizing calculations)
Converts velocity into velocity pressure and vice versa