One of our most popular catalog items! 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