Can I make a downdraft table out of my Hepa Filter?

[Bob]

Hello,

I need a downdraft table. I was think of making one around this Holmes Air Filter I picked up at a garage sale. It is one of the big round ones (retails for 200-300 dollars). Im a newb so Im not sure if it will have enough power or what-all. Has anyone else done this? It seems like a good idea as I got it in almost new condition for twenty bucks! It has a prefilter that wraps around the HEPA filter. I have actually used it by turning it on its side and sanding over it on my knees. You have to be pretty close for it to suck all the dust right in though.

[Bay Area Dave]

Bob, what would you make it out of; pegboard?

dave

Bob wrote:

[Toller]

We bought one years ago but never used it because the noise/effectiveness ratio was just too high; one of the poorer purchases I have made. (well, besides Amazon at $150; just kidding, I didn't do that) I am now using it in my shop but intend on replacing it with a real air filter as soon as I can live with the expense.

The thing is way too feeble to power a downdraft table, or anything else. $20 was a fair price only if the filter has some life in it.

[Clarke Echols]

The short answer is: No, it won't work for what you're trying to do. You need far more than a typical living-room HEPA filter can provide. Those units are for typical living space use, not for woodshops. Even if they worked, the filter would plug up in almost no time at all.

You need a real dust collector that pulls at least 800 CFM (cubic feet per minute), 1200 or more is even better, and I'm not talking about the CFM numbers you see on popular dust colectors marketed by some importers where they don't give you any idea about how they determined their "specifications". I'm talking about 1000 CFM or more

***AT*** not less than 7 inches of static pressure.

I suggest you spend some time on Bill Pentz's web site and get well acquainted with the ins and outs of woodshop dust collection so you'll be well informed and able to pick apart the nonsense specs some outfits put on their products. Bill has done more research on the subject of dust collection in small woodshops than about anyone on planet Earth. He has even designed a cylone system and kits are available

-- details on the site.