[Anthony Kouttron] wanted a fume extractor for his personal electronics lab, but he didn’t like the look of the cheap off-the-shelf units that he found. Ultimately, he figured it couldn’t be that hard to build own portable fume extractor instead.
The build is based around a mighty 110-watt centrifugal fan from an IBM server that’s rated at approximately 500 CFM. It’s a hefty unit, and it should be, given that it retails at over $200 on DigiKey. [Anthony] paired this fan with off-the-shelf HEPA and activated carbon filters. These are readily available from a variety of retailers. He didn’t want to DIY that part of the build, as the filter selection is critical to ensuring the unit actually captures the bad stuff in the air. He ended up building a custom power supply for the 12-volt fan, allowing it to run from common drill batteries for practicality’s sake.
Few of us have need for such a beefy fume extractor on the regular. Indeed, many hobbyists choose to ignore the risk from soldering or 3D printing fumes. Still, for those that want a beefy fume extractor they can build themselves, it might be worth looking over [Anthony]’s initial work.
We’ve seen some other great DIY fume extractors before, too. Even those that use drill batteries! If you’ve been cooking up your own solution, don’t hesitate to drop us a line!
Neat to see this project here! It’s currently changed a bunch since I last updated this article (1yr ago) and the PCB has been completely redesigned. The one I posted was a proof of concept. The writeup is very much not completed yet. I have a bunch of more images and content that I’m working on that has not been uploaded yet so stay tuned :D
It is a cool project! I have several old PC power supplies that could be repurposed in a similar way, as all I am using now is a old far without an enclosure.
Thanks! I actually found my first one of these server fans in ewaste and it just so happened to be the perfect fume extractor testbed.
Except it’s not extracting anything, it just spreads fumes around.
A cheap ducted fan and elastic pipe would actually move fumes outside.
This is a centrifugal fan with several stages of filtration. The above photo is not showing the fan project in it’s full extend. I’m updating my project site with more images at this moment to show what I’m up to. It uses a slide on carbon and HEPA filter assembly that’s rather elegant.
Nice build! I love the internal shot of the blower motor assembly.
Thanks! I enjoyed the rendering work quite a bit but I’ll need to update some renders to include the newer parts :D
If anyone reading this has found a source for inexpensive flexible tubing that’s like 75-100mm in diameter so I can bend the intake down to sit right over where I’m working, I’d love to hear what they’ve found. There’s lots of stuff in the 12-25mm range, but large tubing that you can bend and that then maintains its shape is a lot harder to find.
Use the cheap stuff that’s super flexible and doesn’t hold its shape, and stick the end on an arm you can position as you want. If you look on eBay etc you’ll find dust collector hoods designed for this.
This is the normal solution used by turners etc.
I really like the hakko stuff, it holds its shape, but it is a bit pricey:
https://www.digikey.com/en/products/detail/american-hakko-products-inc/C1572/6228792
Yeah, the stuff Metcal used on their fume extractors is fantastic but breaks after a while and is not cheap.
I’m reliably informed that in medical use, it’s common knowledge that at some maximum static pressure a HEPA filter’s filtration ratio will suffer and it will let through more than it’s supposed to because of the force of air. You couldn’t just blow compressed air through a spare p100 or n95 mask and expect it to work, as an extreme illustration. The pressure limit will correspond to some maximum CFM when the filter’s flow resistance is highest at end of life. The maximum reasonable CFM of filters of this size, as far as I knew, was much lower than 500. I filter the air in my bedroom with some $10 watermelon sized cylindrical filters of fairly high area and similar concept to this. The device they’re made for (which I don’t use) was only supposed to be about 150 cfm.
That being said, for dealing with fumes maybe the charcoal is the more important, and maybe the filters can be abused while still offering good results. I know when people filter with box fans and furnace filters, they generally don’t get high filtration efficiency (especially as MERV filters are not as tight as HEPA of the same number) but they filter the air multiple times due to the flow rate, and eventually may remove just as much contaminants. I fully expect the creator has done better than how I’ve made it sound, but I’d be interested to hear how this differs from what I was talking about.