Dust collector question, can it be too big?

[Damon McLaughlin]

My dust collector motor quit working last night. It was a small portable dust collector rated at only 440 cfm. I'm trying to decide on a replacement and initially thought I would go with the next size up which is rated at 660 cfm which would probably be fine for when I'm sanding at the lathe or using the bandsaw. However for a few dollars more I could get a much larger one rated at 1500 cfm. I think it would be better suited for the band saw work and maybe over kill at the lathe.


My concern is that 1500 cfm could potentially be too much. My shop is 200 square feet. During half the year I keep the doors open when I'm working so drawing 1500 cfm shouldn't be a problem. However in colder months I have the doors closed and an electric heater running. Will 1500 cfm be too much draw with the shop closed up? I could open a window but then I'm going to have a cold shop again.


Would it be possible to use something like this (https://www.amazon.com/Lighthouse-Hydro-Variable-Speed-Controller/dp/B00BLOSG7I)to control the speed of the dust collector thus reducing the cfm for the times when the shop is closed up? I had no issues running my previous (smaller) one this past summer.


Thanks for your insight.

[andy bessette]

Get the 1500 cfm.

[Bob Coates]

Harbor freight has there 1500 cfm on sale for 199. Plus on monday a 25% off coupon.

[Brice Rogers]

Reading between the lines, I'm assuming that you are NOT venting outside. So, venting inside (through a filter) and having a high CFM DC, won't pull in any outside air - - it'll just recirculate it.

If you are planning on running wood chips and strings of shavings (like from your lathe) through it, plan on adding a separator of some sort before the suction unit. Otherwise it'll quickly plug up with shavings.

[Larry Frank]

There is a big difference between rated cfm and actual. The HF will be lucky to actually get 600 cfm. To actually draw 1500 cfm you need 3-5 hp with a 15" impeller.

[Reed Gray]

For a 200 sq. ft. shop, some thing in the 600 to 800 cfm should take care of just about anything. They are rated at cfm, and static pressure, two different measures. Only ones I would really trust are Oneida, and Clear View. They are not the cheapest, but they are the best. Oneida has some that have the smallest footprints, and pleated paper filters which are the best ones available and you will not get dust vented back into the shop every time you turn it on. Not sure about Clear View because they weren't around when I got a centralized DC for my shop. A 2 stage system has a cyclone that gets out every thing before it goes through the fan blades. Really handy for when you suck up some chunks, or a light bulb, or some thing you are turning......

robo hippy

[Damon McLaughlin]

I'm running through a trash can separator to collect the shavings and then venting outside. Because I'm venting outside I'm concerned about 1500 cfm being too much air movement when I have the shop closed up during the winter. I'm using an electric heater.

[Damon McLaughlin]

I was talking to my neighbor this evening and he said he had a HF dust collector, the one rated at 1500 cfm. And it was on wheels. So he brought it over and we gave it a try. It worked great, so much better than the small one I had. Now I'm happy that my small one bit the dust. So now I'm just waiting for Monday to use the 25% coupon.

[Lance Mirrer]

The harbor freight is very decent for it's size and price. I have been using mine for several years. Note, it needed "help" out of the box. things like tightening screws by all seals, adding support to uprights, taping the the areas dust could escape, etc. (possibly things that would help any collector).
Since I do not vent outside, a major upgrade was replacing the filter bag with a Wynn canister filter (specific info available if interested). I also just built a Thien separator (too new to confirm effectiveness).

[Olaf Vogel]

IMO you can't go too big. The more dust you can suck out the better.

My shop is 600 sq ft, but the dust collector is 4000 CFM.
It goes through a cyclone to pull out the big stuff.

In the summer, I vent the exhaust outside.
In the winter I recirculate - to keep the heat in. (and I try to save all the major sanding for when I can vent the exhaust)

Obviously there's a splitter in the exhaust path and two gates to control the flow.

[Randy Heinemann]

I doubt you can go to large if the collector puts filtered air back into the shop rather than outside. In my opinion, Oneida is the best and their cyclones have worked well for me over 20+ years; most recently with a cyclone and HEPA filter. Any dust collection is better than none, but take a look at the percentage of and size particles filtered by the filter before putting the air back into the shop. Some don't filter very small particles and those are the most harmful.