Choosing the right Canister Filter for my DC

[Dan Case LR]

A few years back, I had to suspend my woodworking because of health problems on the part of my wife. She has a long list of serious (some life-threatening) allergies, Lupus, Diabetes and (fortunately) good insurance. One of her allergies is to wood tars, and the fine sawdust was making a difficult period even worse, so I quietly shut it down and took out my creative urges on something less hostile.

These days, her allergies have been under control for a while and she's insisting I get out into the garage and make sawdust again. I'm agreeable to that of course, but I know I need to do a better job of managing the dust. I've decided to build a ductwork system to use with my Penn State Industries DC-2 (1 1/2 HP) bag-style dust collector, and I'm reworking the DC-2 to increase its efficiency and get rid of those big felt dust distributors it came with.

I used to have a shop-built garbage can separator, but I've decided to regain that precious floor space and add an internal baffle based on Phil Thien's excellent design. I'm also switching to a canister-type filter, and that's where I'm sitting on the fence--and the fence ain't very comfortable if you get my drift, so I'm looking to get off of it ASAP.

I know that canister filters have been discussed to death here and on other forums, but there are still some questions in my head I haven't been able to resolve. Penn state offers two different canister filters for retrofit to the DC-2; one is 24" high ($199), the other is 40" high ($239). Basic engineering sense tells me the 40" filter will have more surface area and is preferable if I have the headroom. However, the lack of technical details on the PSI site doesn't do much to inspire confidence--sometimes bigger really isn't better. Anyone have hands-on experience with these two filters? Are the Penn State filters paper, polyester, or something else? If it's a paper filter, my next call will be to order a washable filter from Wynn.

Speaking of Wynn, I know many of the guys on these forums prefer them. All filters being equal, Penn State has an advantage in that it's a direct replacement, while Wynn requires a donut on this model. I've got a router and lots of suitable scrap, so building the donut isn't a problem, just time I could use elsewhere. Depending on which filter media I choose, Wynn will cost between $153 and $168 (I don't want the 80/20 paper version). The other plus with the Penn State is a built-in flapper; building one isn't rocket science, just more time. The flapper question raises yet another: I've read claims that when using a Thien baffle in a DC like this, the flapper isn't really necessary (or at least isn't as critical). Comments?

I don't mind paying (within reason) for what I need, but I do mind paying for stuff that doesn't matter. Somebody knock some sense into me and help me off this fence! :eek:

D.

[Phil Thien]

One of the reasons the donut/Wynn works well is that you can remove the filter w/o having to first remove the baffle.

Does the PSI filter attach in such a way that you can remove it easily w/o having to access the unit from underneath?

[Dan Case LR]

One of the reasons the donut/Wynn works well is that you can remove the filter w/o having to first remove the baffle.

Does the PSI filter attach in such a way that you can remove it easily w/o having to access the unit from underneath?


The diameter of PSI's filter is such that it fits over the ring and is held in place by handscrews (with knobs). I haven't disassembled one, but it looks like it's a breeze to remove: http://www.pennstateind.com/library/DCANISTERS_ins.pdf


D.

[Phil Thien]

Convenience of mounting is a worthwhile consideration. If you had to mount the filter from below, I would have told you to run (not walk) to Wynn.

They (PSI) doesn't have any specs on filter media or square footage? I'd sure want some data before proceeding. Have you tried calling them?

I might still advise going to Wynn. At least you know for sure what you're getting.

[Dan Case LR]

I've got an email in to PSI asking for filter specs. Both a test of their customer service and of the filter. If I don't like the answer (or don't get one) I'll break out the circle jig and call Wynn.

D.

[David Hostetler]

Since your wife has such severe allergies, and this may all depend on the setup of your shop / house and how everything is arranged. But for me, i can just walk into the house, and step into the laundry room and change clothes right off the bat. That way she isn't exposed to anything I bring on on my clothing.

As to the filters, I am not sure about the PSI filters, but the Wynn has been widely tested by reputable engineers, and each model of theirs passes with flying colors. I have no idea what the PSI filters spec out at, however, after using PSI filters in my ambient filter for a while now, it seems to be the same material on those as my Wynn canister on my DC. The question is, without published specs from PSI are you willing to gamble?

Take a look at Phil Thien's forum. There is a common mod out there, it's a bit of work, but will seriously improve your aiflow. Take the motor / impeller housing and basically pick it up and spin it sideways so that the output from the impeller is a straight shot to the inlet ring, and the input to the impeller housing points straight down, then mount your Thien type drum separator. That is a modification I am wanting to do with my HF 2 HP (yeah right) dust collector. I need every bit of DC I can get, and every inch of floor space is precious...

If you haven't read Bill Pentz' web site, I recommend it. It is mind numbingly detailed, but packed with good information. It might scare you about using a single stage DC, but again, with a separator, and a canister filter, they can and do work well for smaller shops with small budgets...

If you have, or can come up with the $$ to do it, your best bet honestly, is to trade the bag / canister DC in for a true 2+ HP cyclone... But if you are like me, for now at least, that is beyond your budget...

[Rick Potter]

On a separate note,

I am sure you have thought of it, but is there any way you could build a small shop that is not attached to the house?

Rick Potter

[Dan Case LR]

Take a look at Phil Thien's forum. There is a common mod out there, it's a bit of work, but will seriously improve your aiflow. Take the motor / impeller housing and basically pick it up and spin it sideways so that the output from the impeller is a straight shot to the inlet ring, and the input to the impeller housing points straight down, then mount your Thien type drum separator. That is a modification I am wanting to do with my HF 2 HP (yeah right) dust collector. I need every bit of DC I can get, and every inch of floor space is precious...

That's a good modification--I've often wondered why in the world they didn't mount the blower that way in the first place (ANSWER: to save a couple bucks, of course). Rather than a Thien drum separator, I'm going to try a Thien baffle inside the ring. If the reports I've seen are true, the results are comparable without losing any floor space. I can always yank it out and build the drum if I don't like the result.



If you haven't read Bill Pentz' web site, I recommend it. It is mind numbingly detailed, but packed with good information. It might scare you about using a single stage DC, but again, with a separator, and a canister filter, they can and do work well for smaller shops with small budgets...

I've read Bill Pentz' site, and now I'm afraid to go into the garage at all. :) Lots of good information, but definitely mind-numbing (which doesn't take as much now as it used to).

I'd love to have a cyclone. Not in the budget for now.

D.

[Dan Case LR]

On a separate note,

I am sure you have thought of it, but is there any way you could build a small shop that is not attached to the house?


I wish that I could. We live in town and don't have ground for it.

D.

[ian maybury]

There's a view about that suggests that it's better to buy HEPA cartridge filters from reputable sources - that there's otherwise a risk that they won't do what they are supposed to do.

One question that comes to mind Dan is whether or not a can separator drops out the dust well enough to avoid blinding a fine cartridge filter too quickly. Phil or somebody else no doubt has experience.

It depends quite a lot on your climate, living in a town it may not be an option, and it would up your heating cost - but another option might be to exhaust your dust outside while only running the system when you are cutting to minimise heat loss.

This is speculative, but an in between solution (especially if the dust retention of the can isn't great, and the local regulations prevent your exhausting outside) might be to use a bag filter (which isn't going to do much to filter out fine dust), but locate it in a cabinet outside so that you are in effect exhausting outside but through it.

ian

[Dan Case LR]

One question that comes to mind Dan is whether or not a can separator drops out the dust well enough to avoid blinding a fine cartridge filter too quickly. Phil or somebody else no doubt has experience.

It depends quite a lot on your climate, living in a town it may not be an option, and it would up your heating cost - but another option might be to exhaust your dust outside while only running the system when you are cutting to minimise heat loss.

ian

Unfortunately, Ian, exhausting to the outside isn't an option in my neighborhood, and I don't have an outside space where I could locate the equipment.

Based on the reading and research I've done, the combination of a good canister filter and Phil's baffle design is the best option I have at this juncture. The PSI DC-2 uses a spiral helix instead of an orifice plate. I think the combination of the spiral helix and Phil's baffle should perform well and minimize the amount of dust that makes it to the top filter. At least that's my hope and expectation. Phil, am I right (or at least in the right neighborhood)?

D.

[Phil Thien]

The PSI DC-2 uses a spiral helix instead of an orifice plate. I think the combination of the spiral helix and Phil's baffle should perform well and minimize the amount of dust that makes it to the top filter. At least that's my hope and expectation. Phil, am I right (or at least in the right neighborhood)?

D.

It has worked for others, should work for you, too.

[Dan Case LR]

Well, I've made my choice.

As of this writing (three days after sending an email through their website), PSI hasn't responded. The argument could be made that I didn't call them, but I believe strongly that a company engaged in e-commerce ought to answer emails in a timely fashion, so PSI fails.

A few minutes ago I called Wynn Environmental and discussed my needs, and Dick Wynn recommended the C-1425C filter, which has a flange on the bottom that will allow it to be screwed to the donut and easily removed if necessary. It's also a nanofiber filter that is extremely efficient (99.999% efficient at 0.5 micron, compared to 99.9% at 1 micron for the spun bond filters). That filter in combination with the internal Thien baffle and new, improved ductwork will provide the best performance for my current situation.

BTW, Dick told me the PSI filters are spun bond (otherwise, the flappers would tear them up). Even if PSI's biggest filter performs as well as Wynn's spun bond (doubtful), the filter I ordered has considerably more surface area, higher efficiency, and better filtering for $72 less, and I believe Wynn's shipping charge will be substantially lower as well (PSI charges $46 for ground shipping for theirs, Wynn charges actual cost of FedEx Ground).

And, to echo what I've heard others say about doing business with Wynn, on a scale of 1 to 10, I'd give them a 15. Friendly, helpful, good people who didn't try to do any up-selling and were as friendly and helpful as anyone could be. If only the vendors I deal with regularly were so customer-oriented and friendly!

Thanks, all who helped. This has been my first venture into the SMC community, and has been a great experience.

D.

[Rick Potter]

Sounds good Dan,

I hope this works well for you (and your wife).

Rick P

[Aleks Hunter]

Hi Dan,

Your wife's health is what matters. Given what you said about her health, it appears that you do need a system that is meets hepa standards at a minimum, and have shop air cleaner and that your tools are all adequately shrouded. Next to that everything else falls into the "doesn't really matter" category. THat said, Wynn's nanofiber seems the way to go. when it comes to dust, always sweat the small stuff!