Finding The Right Filter For A DC

[Julie Moriarty]

My DC is an old Delta canister, model 50-179. The motor is 3/4 HP. All ducting is 4" with the joints taped with reinforced foil tape.

According to what I've found online, the CFM is 650. There is nothing about CFM in the original manual. When I converted it to a cyclone, it seemed to increase CFM output. I don't have anything to get an accurate CFM reading.

I'd like to tap into the existing output, which is ducted to the outside, and install a canister filter, preferably a HEPA, MERV 16 so I can switch between outside ducting and the interior filter. Plans are to cool the garage in the summer, thus the interior filter.

The question is how to determine the correctly sized filter based on CFM. Any suggestions?

[Peter Christensen]

An old FWW article said 1 square foot of filter for every 10 cubic feet of airflow. That was for the days when there were virtually no cartridge filters to be had on a small shop dusty and none filtered down to a MERV 16 level. Not that common even now. You might be best off to look at the Clear-Vue and Oneida air flow specs and compare them to their filter areas. Take those ratios as a minimum.

While literature may claim 650 cfm I doubt that is true. Those numbers are usually taken with the motor and impeller only and not in a system. From everything I have read you can't pull more than 425 cfm through a 4"pipe. less through flex.

[Matthew Hills]

Julie,
I'd recommend contacting one of the places that sells filters.
Total filter area is one factor (I think going with extra area should be okay here).
Getting a good attachment method would be another factor.

Wynn Environmental is probably the name I see mentioned the most for after-market cannister filters.

American Fabric Filter is another name that I've seen mentioned for bag-based systems. (you'd want to go oversize with these, as well; have heard singed felt can be good). This might be the easier attachment method.

Matt

[Nick Decker]

+1 for Wynn. I forget his name, but the guy that runs the place is knowlegeable and easy to talk to.

I'd recommend getting a filter with more area than you think you need. If you restrict the exhaust, it cuts down on intake. Also, it sounds like you may eventually be upgrading, and it'd be smart to have a filter that can handle more CFM.

[Julie Moriarty]

Thanks guys. I've been looking for places that carry dust collection filters until my eyes cross. I had hoped to find something for around $100. None of the websites I found included the CFM handling capabilities of the filter, only sq/ft. Most of the filters I found that seemed to work (based on limited knowledge) put the price at $180 on up. Is that typical?

Wynn had a photo of my DC in it's original state (for me that's pre-cyclone add on) with one of their filters. That filter had 200 sq/ft MERV 15 Nanofiber filter media. Price is $188. For the same price they have a MERV 15 with 274 sq/ft of Nanofiber filter media.

On the other hand, Oneida's filter for the Mini Gorilla is $180. According to the website, their filters are "True HEPA". No idea the value of that. They are MERV 16+. The Mini is said to have "up to 600 CFM" air flow. Their motor is twice the HP as my DC. The price for the filter is $180. Oneida says that filter has 40 sq/ft of media. Are they using different means to measure sq/ft than Wynn?

[Nick Decker]

I'd say you should expect to spend around $200 for a good filter, whether from Oneida or Wynn.

Any kind of separation device, whether it's Thein or cyclone, will cut down on CFM. Not sure how your CFM would have increased when you added a cyclone, if all else was equal.

Please know that I am far from expert on this stuff. I can say with certainty, though, that when I added the Wynn filter to my meager setup, the dust level in my shop went way down. Easy to judge just from the amount of dust that coats everything, so I have to believe I'm breathing less of it.

[Julie Moriarty]

Not sure how your CFM would have increased when you added a cyclone, if all else was equal.

I used an extremely accurate measurement techinque after installing the cyclone add on - "Wow! Sure seems to work better!"

[Mike Heidrick]

Prob easier to just get a second $100 dust collector.

[Nick Decker]

I used an extremely accurate measurement techinque after installing the cyclone add on - "Wow! Sure seems to work better!"

Ah yes, I'm familiar with that method and often resort to it myself.

Seriously, there's plenty of "science" out there to cross your eyes. What I try to keep in mind is that air travels easiest in a straight line. When it comes to a cyclone it has to go around in circles for a while, which slows it down.

I've read that Thein baffles are more efficient, but then Oneida claims that cyclones are better. But, Oneida sells cyclones. Etc., etc....

[Peter Christensen]

When on the filter hunt you should also be checking to see if it is designed to filter from the inside to the outside. Most industrial filters filter from outside to the inside to facilitate reverse flow cleaning etc. Oneida make them for inside to outside and Wynn make both kinds. Others like Donaldson Toritt make them for outside to inside for all their machines. So if you find something cheaper make sure it will filter to suit your installation or you will have to make a cartridge house to make them work correctly.

[Julie Moriarty]

I was all set to buy the Oneida 40 sq/ft filter (13"Hx13"OD) when I saw they want to charge $28.50 for shipping. They charge by price rather than weight or size. Going to do some more looking around.

[Peter Christensen]

Searched for dust collection cartridges Florida and these guys are in your state. Worth a call maybe?

https://www.gulftech.us/manufacturin...trial-filters/

[Peter Christensen]

Had these guys bookmarked, I think because they are low cost.

https://damnfilters.com/collections/...ter-cartridges

[Julie Moriarty]

Thanks for the links, Peter. I'll check them out.

[Mike Kreinhop]

Wynn had a photo of my DC in it's original state (for me that's pre-cyclone add on) with one of their filters. That filter had 200 sq/ft MERV 15 Nanofiber filter media. Price is $188. For the same price they have a MERV 15 with 274 sq/ft of Nanofiber filter media.

On the other hand, Oneida's filter for the Mini Gorilla is $180. According to the website, their filters are "True HEPA". No idea the value of that. They are MERV 16+. The Mini is said to have "up to 600 CFM" air flow. Their motor is twice the HP as my DC. The price for the filter is $180. Oneida says that filter has 40 sq/ft of media. Are they using different means to measure sq/ft than Wynn?

I don't think Onieda is using a different method to determine the filter area, but the filter on the Mini Gorilla is considerably smaller than the Wynn 35BA series filters. The filter on the MG is 10.5 inches in diameter and 19.5 inches long. The Wynn 35BA222NANO is 17.5 inches in diameter and 23 inches long. I'm sure the differences are also in the filter material pleat dimensions, which contributes to the overall filter area.

Before I bought my filters and accessories, I emailed and spoke with Dick Wynn several times to determine which filters would meet my filter requirements and could be mailed to my APO address. He took the time to double box the filters so they would survive the tender mercies of the postal system and international baggage handlers.

Here is a PDF from the Wynn website showing the comparison of some Onieda and Wynn filters:

http://wynnenv.com/dev/wp-content/up...chart_2017.pdf