The great vacuum versus DC for small tool use debate.

[Wade Lippman]

Playing with my new anemometer, I measured 95 mph on a 1.5" hose attached to my my dyson vacuum, and 120mph (I am guessing because it went off the scale, but at the rate it was climbing, I am guessing it would have hit 120mph) on the 1.5 hose attached to my DC. That means the vacuum was drawing 90cfm, and the DC about 115.

So, a DC should be at least as good as vacuum for small tools. Am I understanding this properly? Of course it would be using 4x the electricity to do it, but that's besides the point.

I also measured a 1" hose off my vacuum at 100mph or 50cfm, so a narrower hose restricts air movement by 50%. Who knew! I didn't test the DC on a narrower hose, since I couldn't have accurately measured it anyhow.

[Art Mann]

No, you don't have the whole picture. Small tools have a very restrictive air flow path and low air movement. A shop vacuum is designed to maintain suction in this kind of situation. A dust collector is designed to work with open air flow paths and big volumes. Air flow restrictions have a much greater effect on air flow. The one experiment that you did not do would have showed you the real difference in how dust collectors and shop vacuums work.

[glenn bradley]

What Art said. There are some capture scenarios that benefit from sheer suction and velocity with point of origin "suck" being the main contributor to capturing spoil. Stuff flies off a router bit at a pretty decent speed. If the suck (or capture cowling) can't overcome the launch speed, no capture. Random Orbit Sanding is another matter but, I have found most dust collection discussions end with the right answer being whatever works best for you ;-)