CFM Wheel

CFM Wheel is a complete duct sizing wheel for your phone. It functions similarly to a classic ductulator wheel: every scale is printed on a real two-part wheel, and one turn solves them all together. EVERY SCALE ON THE WHEEL • Airflow: 25 to 25,000 CFM • Friction loss: 0.01 to 1.0 in. w.c. per 100 ft • Round duct size: 3" to 40" • Velocity: 100 to 5,000 FPM • Rectangular duct: sides from 3" to 60", equivalent to any round size HOW TO READ IT Turn the wheel until your friction loss lines up with your airflow on the blue scales. Read the round duct size at the arrow and the velocity in the red window. For rectangular duct, find one side on the green scale and read the matching other side. Work it in any direction: size a new duct from CFM and friction loss, check what an existing round or rectangular duct will carry, find the friction loss for a known duct and airflow, convert rectangular duct to round and back, or check velocity for noise. BUILT FOR THE FIELD • Pick a design friction loss from 0.05 to 0.20 and it is marked on the wheel • Drag to turn, pinch or double tap to zoom • Arrow buttons for fine and fast steps • Light and dark mode • Works offline. No account, no ads CFM Wheel is $3.99 per year, charged to your Apple Account. The subscription renews automatically unless cancelled at least 24 hours before the end of the current period. Manage or cancel it anytime in your App Store account settings. Scales follow the standard friction chart equation for galvanized round duct carrying standard air, with Huebscher equivalents for rectangular duct. CFM Wheel is for estimating and field checks; confirm final designs against your design standard. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://serviceairflowcalculator.com/cfm-wheel/privacy