Do cyclone filters wear out?

[Bernie Kopfer]

Asked this question in another thread but it got lost in the conversation. Does anyone know if the Filters we use on our cyclone dc's wear out, or become permanently clogged? Oneida says to replace their filters in 5 years. Why? Is there any sort of test that can be done w/o special instruments etc to know that suction/cfm is down significantly?

[Jim Becker]

I will speculate that even with normal, regular maintenance, a quality filter will over some period of time retain enough super fine material to affect its performance. I seriously doubt that the actual material degrades much, if at all, but I could be wrong about that. I'm not sure that could be called "worn out" in the common sense of "worn", but it certainly can be referred to as having efficiency reduced to the point that replacement is worthy. IE, the "clogged" you mention, but at a microscopic level. Do keep in mind that the 5 years that Oneida is suggesting likely applies to a system that's being used at some minimum run-time level which may not represent how many/most folks who are hobbyists are running their systems. The type of machines being serviced also likely matters...big sanders are going to be harder on the filter than table saws and jointers/planers, etc., due to the nature of the debris they produce. I've had my current Oneida cyclone for a dozen years at least (I think without looking it up) and it's only been recently since I retired and started my woodworking business on a more formal basis that I've been running it for substantial hours. Even then, the long run time is because of my CNC machine and the amount of material actually heading to the system is minimal. Historically, I've cleaned my filters about twice a year whether they needed it or not...or if I, um...clogged them due to my own stupidity, whichever came first. I've had no noticeable decrease in efficiency and very little debris end up in the catch-bin at the bottom of the filter.

[Jamie Buxton]

I think there's two possible failures mechanisms in a DC filter. One is that the filter gets clogged, so little air goes through it. The other is that the filter gets holes in it, so it lets through lots of particles you're trying to catch.

To see clogs, you can measure air velocity through the system, or measure back pressure in front of the filter. For air velocity, you can buy an inexpensive device to measure wind speed. Amazon shows lots for twenty or thirty bucks. For back pressure, you can build a manometer. Either of these approaches has the added benefit of telling you when it is time to clean the filter.

To see a leaky filter, you can buy an instrument to measure air quality, like the Dylos devices.

[Mark Carlson]

I'd say yes. My cyclone is a SDD so not a real cyclone. Larger cyclones are much more efficient at separating the dust. I monitor the pressure inside the filter with a manometer. When the pressure reaches a certain value I clean it. I never get back to original new values and it increases gradually over time. So my filter is getting more and more clogged. I also monitor my air quality constantly for spikes which might indicate a leak or that I damaged my filter some how during cleaning. About every 3 years I replace with a new wynn cartridge filter. The other benefit to replacing is filters seem to be improving and have more surface area and better merv ratings. The cost is of course increasing.

[Peter Christensen]

There would be two reasons that come to mind for replacing the filters. First would be leaks from holes from handling, cleaning (paddles especially), glue/sealant breakdown at the fabric to flanges or the material wearing out over a long period of time like an old flag. The second would be from getting clogged beyond the point of cleaning.

In the first case the easiest way to know is to have a particle counter. If they were leaking the particle counter would show the dust levels increasing with the same kind of work being done and not going down with the work stopped but the collector running. They used to be very expensive until the Dylos counters brought the cost down to expensive. Now there are a number of counters you can buy for under a hundred dollars and the costs are dropping all the time.

The second case means monitoring the filters from when they are new or at least conditioned and clean so you know when they are filled up. If after cleaning they are still plugged it is time for replacement or if it is an industrial filter like a Wynn, sent off for cleaning. After cleaning they will be tested for flow and checked for damage. Industrial filters (Asian paddle filters fall apart during some cleaning processes) can be cleaned several times bringing them back to almost new airflows. On the Wynn site there is a link to a youtube video on making a manometer to check the static pressure of the filters showing you when they are getting plugged. It is a simple contraption and you only have to make sure the fluid hasn't evaporated over time.
https://www.youtube.com/watch?time_c...&v=a9l9e8PwgEs

I type too slow. Mark and Jamie are quicker.

[Alan Lightstone]

My Oneida one disintegrated when I took it off to move the cyclone. Wasn't pretty.