Ductline: HVAC Duct Calculator

Every number in Ductline can show you where it came from: the equation, your own figures substituted into it, and the standard it follows. Tap any result to open the working. That matters, because a duct calculator that disagrees with the one in your other hand is worthless until you can see which of them is wrong. WHAT IT SIZES • Round, rectangular and flat-oval duct • Size by friction rate (the equal-friction method) or by velocity • Solve in any direction: size from airflow, airflow from a size you already have, or the pressure drop of either • Convert between round and rectangular at equal pressure drop with the Huebscher equation, not a rule of thumb • Whole systems: supply and return paths, segment by segment, with the critical path identified for you REAL PHYSICS, NOT A CHART LOOKUP Ductline solves the Colebrook–White equation for the actual Darcy friction factor, from your…