Posted on **My first dust collector**

#1 posted 08-30-2016 03:15 AM |
I’ll try to explain with two examples. See, all dust collecting efforts require the right balance of flow and pressure. Google “velocity pressure chart”. Velocity is how fast air moves. The corresponding velocity pressure is the pressure required to make air move at a given speed. If you have a 4” duct and you want to force 400 CFM of air to pass through it, figure the cross sectional area of the duct in square feet. you should come up with about .087 sq.ft. Now take your 400 CFM and divide it by that area. 400/.087= 4597. That is 4597 FPM (feet per minute) the air will have to flow to get 400 CFM through that 4” duct. Find the velocity pressure in the chart you Googled for 4597 FPM and that is the pressure required to generate that flow. |