Dust Collector Performance Measurements

[David L Morse]

Alan, here's what I get when I plot your data:
Fan Curve.jpg
Current.jpg
I left out the all closed data point, it looked a bit odd.

[Joe Jensen]

I didn't get the anemometer to determine the exact fan curve but rather to measure objectively relative changes. The engineer in me spent a couple of hours last reading and considering installing a pitot tube and gauges. Then I realized that I just need to measure to see in changes help or not.

[John Lanciani]

One piece of advice for anyone who is looking for test equipment is to keep an eye on eBay. I got my Dwyer hot-wire anemometer for under $100 in as new condition. There are still deals to be had if you're patient.

[Scott DelPorte]

I took a little different approach to computing the CFM for my dust collection system. My dust collector is in a separate room adjacent to the shop with the air returning through a grate. The grate manufacturer publishes the pressure loss through the grate as a function of CFM. So I connected a magnehelic gauge to measure the static pressure difference across the return grate (between the room with the collector, and the shop), and then computed the overall system CFM based on the grate's loss curve from the manufacturer. A manometer would have worked instead of a magnehelic, but it just seemed easier for my eyes to read off the needle on the gauge.

[Michael W. Clark]

A magnehellic setup to read static is ideal for monitoring changes. Connect one port to the duct and leave the other one open. A change in flow give a large change in static because the SP varies with the square of the flow change. You probably want at least a 0-10" gauge, depending on your collector and system.