Duct Size Calculator / How to Size Duct
How To Calculate The CFM Requirement In a Wood Shop
By either clicking on the picture to the left or go down to "Downloads" you will be able to download my free cfm calculator which is used for correct duct sizing as it will do all cfm in duct calculations for you. The Excel duct calculator file contains 3 different tabs:
CFM Calculator
On Tab 1 of the Excel file you will be able to list all the machines in your shop and put in the port size for each machine. By telling the duct calculator which trunk-line / dust collector you would like each equipment to be connected to the program will then show what trunk-line size you will need and the total cfm requirement (@ 4,500 ft/min standard but you can change that). The total CFM in the duct is automatically calculated. Duct sizing made easy!
Printed CFM Numbers
On Tab 2 you will see the cfm (cubic ft/min) volume in different duct sizes at different velocities. 4,500 FPM is the standard for wood applications so that is what has a yellow marked background. You will see that the file shows the cfm for velocities more and less than the 4,500 FPM as well (standard at 100 more or less but you can change that in cell G4). Easy way to look up duct sizing if you know the desired velocity and cfm requirement.
Project information
On Tab 3 is a Project Information tab and can be used to help show me how you would like your system to be quoted so please submit a filled out form along with a scaled drawing of your shop and I will be happy to make a 3D duct drawing for you. You can also email it directly to me at nh@industsolutions.com for correct duct sizing.