Simple room air filter experiment

You could use a face-mask - even has elastic straps to attach it to your filtration unit

Gordo

Clive, Clive. "take it off and throw it in the bin", we're Scottish, we don't throw stuff away, there must surely be *something* one could do with a piece of (only slightly soiled) toilet paper...

Gordo

The idea of having the fan rotation also drive a gear train to (very slowly) continuously advance the soft, strong, and very long, filter element from a supply roll to a take-up roll, is genius. the 365-day air filter?

David Reader

If you use round holes you are likely to have more material blocking the filter. The simple grid you have has a greater filter area exposed.

After seeing this video I thought - I try it out. I have simplified it (as it is just a proof of concept) to a shoe box with kitchen paper in one end and a 12V fan from a broken robo vacuum cleaner, running at 8V to minimize noise. It's been running for a couple of days - and I'm surprised to see how dark the "filter" have become already. For clarity. I think live in a small flat and I do smoke. But what the "box" catches won't end up on my walls and windows. 🙄

Zeedijk Mike

im hoping my sis buys her spawn a 3dprinter... so i can "use" it

Scott Traynor

I think putting the filter on the bottom of the unit and drawing the air up would have some advantages, especially in disposing of a clogged filter. You could hold the running filter over a trash can, cut the power, and let the dusty filter fall down. It also might help a bit preventing it from getting clogged because heavier particles would fall down.

I'm pretty sure I've heard Clive mention Matthias before, but I was thinking the same thing. There was one video I remember where he mounted the filter vertically so that the dust would fall away from it when the power was turned off.

as i said its been years sense i have seen that show.. if your .us/.ca his "latest/last" tour tickets are on his website :)

Scott Traynor

He did use beef to make jerky as well. Multitasker piece of gear. Just don’t use the dusty fan for food.

a tv chief (alton brown - "Good eats") did that to create "dehydrator" for herbs/etc.. its been so many years sense that episode, dunno if he did meat/etc with it

Scott Traynor

We have pets in the house, so I did much the same thing on a large scale, but without any attempt at aesthetics. I just tape a furnace filter to a 20 inch box fan and let it run on low. It’s scary how much that pulls out of the air.

I've ordered a large conical one from eBay to look at.

Big Clive

I always thought the mains voltage fans were noisier and lower throughput than the 12V ones.

Big Clive

Heck, couldn't one a discarded tissue box to build one of these? A sharp blade and a hot glue gun and any fan works...WHERE THE F DID I PUT MY FANS???

Michael Thompson

wonder what the airflow would be via new "cheap" case fans, vs old VAC system fans (AC) as i think i have a few of em still laying around

Scott Traynor

Spent the last 21 years of my working life with filtration systems , learned more than I every cared to know about filtering shite out of the shinola. Recommend you look up a filter media generally known as "Poly-Blue" or "PolyKleen Blue" for filtering air. Really inexpensive, easy to cut to size and traps dust/mold and even smoke.

Mustafa's Fleas

For woodworking there are similar units to this to remove wood dust from the air in the shed/workshop. They're usually a bit larger and more industrial because, well, shed or workshop :) https://www.axminstertools.com/axminster-craft-ac15afs-air-filter-106179 is the kind of thing (they're almost a standard size and made by a dozen manufacturers). The filters, more importantly are paper. https://www.axminstertools.com/axminster-craft-ac15afs-replacement-outer-filter-106182 (you can get higher spec filters using charcoal, but that's more for when you're mucking around with really nasty stuff in the shed than for wood dust) So if you want a commercial source for filters, you could just look for paper air filters and you find they're everywhere in all shapes and sizes for everything from cars to chainsaws to home furnaces and HVAC units to lawnmowers to motorcycles. The motorcycle ones even look kinda pretty: https://www.aliexpress.com/item/1005001941526330.html So of course they make commercial filtering units with this in mind especially since covid: https://www.aliexpress.com/item/32803793686.html And also of course, you can just buy the filter paper itself: https://www.aliexpress.com/item/1005001728886660.html

Mark Dennehy

Looks like the start of a good design. Others have already given much better advise than I can. The only issue with replying on a vacumn to hold the filter in place is that if there is a short power outage, the filter may fall off before the fan restarts.

I don't know much about filtering styrene gas other than to the outdoors. Can the fumes be drawn through isopropyle alcohol or some other fluid to absorb the styrene gas? I shall have to investigate as I have a 3D printer, admittedly still in its box 8 months since delivery. There would still be the disposal issue of the contaminated alcohol.

Try small blower fan, like a 5015 (a common fan used on 3D printers, around $13 for 2 5V ones). Axial fans don't have good pressure rating. Oddly enough, I've been working on a printable air filter this weekend. Need something to filter deal with styrene fumes from printing with ABS. First proof of concept was a simple frame with a large blower fan stuck to the side and a sheet of activated carbon hot glued over the frame. This worked a lot better than I imagined. I was thinking this would require an organic vapor filter and had already ordered a 3M reperator cartridge for testing. 2nd rev is printing now and uses a smaller,and quieter 5015 5V blower with cut-to-fit replaceable activated carbon filters sheets. I buy the filter media in larger sheets for another commercial air filter and they are very cheap in bulk. The whole filter assembly is 100x100mm and will fit in side the printer's enclosure. https://i.gyazo.com/97b1912837064c878d699c7347a33242.png

Kadah

One advantage of this design is that if you ever run out of toilet paper, there’s a secret stash.

Normunds Gavars

The latest version is based on holes, but a stylish array with as many stuffed in as possible. I also added some fins at the edge to break the air vortex.

Big Clive

Its probably already been said but you could easily put in one of those little black potted ioniser or ozone generating modules in the air chamber so the air is nice and fresh coming out. Another idea might be to put a positive charged plate or positive ioniser to attract the dust to the fan? This might work if you are using ionisers at the other end of the room maybe? This project looks really interesting. Gonna have to get a 3D printer soon and start making all these great things! :)

Ross Robertson

I spent a career designing things that used filters and can go on and on endlessly (if invited) but I'll keep it brief. -Yes, a plenum area between the filter and fan is critical. That keeps an even pressure on the filter media. -Yes, randomly distributed fibers are much better than woven. Filters can trap things smaller than their largest pores (through static and Brownian motion). TP is a great idea. Avoid filter media supports that cover filter media (strips are better support than holes). -Air flow is a function of media surface area and static pressure across the media. More filter media w/ same fan = more air filtered. Note every air filter you have seen is corrugated. This done to increase surface area. Make the filter holder wide enough to hold 3-4 sheets to increase air flow. -Putting an ionizer in the air flow before it enters the filter media will dramatically increase the number of particles captured. -during lockdown I built a filter box using a prefilter, Ionizer, electrostatic filter, and finally a HEPA filter. Got some real high power UVC LEDs but haven't worked them into it yet. It's a never ending project after endless iterations.

Bill Kerr

Fume extractors. Required for soldering indoors. Or vent outside. Hey, it works for meth labs!

09Klr650

Anti turbulence fins are a good idea. I had to add them to my silk flames to stop the silk twisting up.

Big Clive

I'm still designing it. That is a prototype.

Big Clive

I just BOUGHT something like this for my Grand daughter , She is learning how to solder and is also was very concerned about the smoke created by the solder (Flux Puff). I bought a couple (side by side) fans because I didn't know if it would generate enough suck! I then bought some carbon filter (very thin sponge like) to pick up the vapors. Way overkill, I wish you would have started this 2 weeks ago. Great Video so far. Looking forward to part 2.

where are the STL files?

As others have noted, yes the air chamber is a good idea. Specifically it helps prevent the problem of turbulence; if the filter is close to the fan blades, it generates turbulence, which both reduces the amount of air it can pull through the filter, and dramatically increases the amount of noise generated. You can improve the effect of the air chamber by subdividing it into smaller sections, as what turbulence does get started can't go all the way around the fan and build up.

Charles

I would recommend checking out Matthias Wandel's channel. He has a bunch of videos about dust collection for woodworking tools. Many experiments that show pressure loss and filtering techniques and air quality measurements. https://www.youtube.com/c/Matthiaswandel/videos

Jeff Larson

Clive, you are right in thinking that the chamber infront of the fan helps create a more uniform air flow through the filter. Being right next to the fan will create a lower pressure right next to the blades and "less lower" pressure where the filter is next to the center of the fan where motor is. You can see the effect as the dirt on the filter creates a ring on the filter where the blades are.

Jeff Larson

Back in my youth I got involved with one of those awful MLM (multi level marketing) things. The products were actually good - water filters and air filters. There was an air filter for a small to medium room with approx 8" x 4" x 1" HEPA filter and mains centrifugal fan. It did work, but the noise was more than you'd want.

Mike Page

Yes - current draw or tach. Less air resistance with lower pressure.

Mike Page

A wet bulb thermometer should allow crude airflow measurement across the inlet.

Mike Page

Ahah - get your bro or a friend to be a morning TV host Youtube style, then he could introduce you and let you do your thing. Five min slots and lots of them.

Ymir the Frost Giant

My first idea was that you could add a loo roll dispenser to one side. Then it occurred to me that this could be mounted onto a bathroom wall for perfectly hygienic poo wipes every time. Then I poo-pooed that idea and got more sensible. Back to table-top (or floor) standing: one way to increase the filtration area whilst keeping to loo paper would be if the void had an arched profile when looking from the side, allowing two sheets to be draped over it. One possible issue - when disposing of a clogged filter, it is so floppy that you'd risk releasing the filtered dust back into the room. So maybe you could use some sort of filter holder after all? But these are all tweaks to what is undeniably a stroke (or wipe?) of genius. Maybe there's no real scope for patenting it Clive, but I could see you getting regular spots on brekky TV with your pocket-friendly ideas.

Ymir the Frost Giant

I wonder if you could monitor fan load to represent filter cloggedness.

Ymir the Frost Giant

I use a single USB-powered PC fan to just take soldering fumes out of my face so my eyes don't sting and my nose doesn't run and, yes, in that situation this would be great. However, as I replied in a comment above, unless you're getting a close approximation to the volume of air in the room through it regularly I doubt it will make any appreciable difference. Anyone with a "gaming" PC can attest that, while they suck a lot of air, the room still gets very dusty. That typed, I may be wrong and, even if I'm not, it's an interesting project.

nowt

Love it. I think you need the air chamber. If you look at the old Remington Purifier units they were a similar design (an AC motor with 2 speeds) but used a propriety filter (perfumed or unperfumed). They were simple, cheap and effective. I would make the holes hexagonal (honeycomb) rather than square for potentially better airflow. If cotton is beneficial to the filtering, some Andrex varieties contain cotton.

Gadgetman

Wonder if you might need a bit larger of a margin between the start of the filter paper and the air holes? so that air is always being drawn through the filter and not under.

Peter Stevens

Burn Something BigClive and watch the smoke stream through the fan or just vape!!!! 🧻🔥 or Vape 💨 Smock Break 🔥🍀😮💨!!!

Zane Revai

Me Too!!! I see BigClive’s crazy awesome creations and I want to print my own or modify it and then print!!!

Zane Revai

Bust Out The UVC+Ozone!!!!

Zane Revai

I Just Love ❤️ Watching BigClive’s Doodles!!! The air void is needed for proper airflow but it can be adjusted for height for different effects on the flow’s speeds. The further away from the fan the filter medium is the slower it will take particles in but the airflow is faster over the longer distance. I’m probably screwing up my explanation but I’ve been playing with similar setup on my Mac Mini’s intake fan for filtering the dust, I used cardboard and paper towels 🧻 with a rubber band holding the filter medium on the tube. The length of the tube did absolutely change the filter effectiveness if it was to far from the fan it would have little suction effect, to close it tried to eat the towel; there was a happy medium of distance vs fan airflow volume to get the best suction for filtering and in my case still cooling.

Zane Revai

It could definitely catch flux residue in the air.

Big Clive

I have a multifan (4) unit behind my monitor to suck away rosin fumes when I solder. I 3D printed a softly undulating filter holder for each of the fans. The filters are carbon impregnated mesh of the type used in pre filters for home HEPA units. Works well to get the smoke out of my face and there is no smell in the small studio. Not absolutely quiet but not loud either.

I wouldn't even try commercialising something like this. The Chinese copies would appear almost instantly.

Big Clive

The original plan was to use kitchen towel, but the size of a 3D printing bed and the printing time are factors in what can be printed. With a wooden cabinet that's different.

Big Clive

The airflow is low, but it's continuous 24/7.

Big Clive

Once I've tweaked it I may release the script and STL file.

Big Clive

Both places are fine.

Big Clive

That all depends on whether there is a connection between anal-abrasiveness and air filtering performance.

Big Clive

The only thing that I would suggest is that the void opens up on the inlet side to accommodate a full-size paper towel sheet. This would provide a much bigger area to draw air through, increasing the total volume of airflow. Also, a provision for a tube attachment on the side of the 'void' would allow a simple Manometer to be hooked up to monitor the vacuum in the void. Then you could see the vacuum rise as the filter starts clogging up. Just my 2 cents.

First thing I thought of was adding an ozone generator in the void. It would add extra cleaning to the process.

John Carr

I'd welcome any device that can reduce stinging eyes from soldering residue.

Andrew Donaldson

The void is a great idea, this will even out the turbulant air flow resulting in a more even flow though the filter rather than directly above the blades. as for the fan finger guide/filter support, the less material there the better, you want to largest surface area possible to maximise the airflow, the fan is already producing a negative pressure in the void, further reduction in surface area will restrict airflow even more and may result in less airflow through the filter and fan, however the negative pressure will be higher.

James

I think Clive should commercialise this. I tried a crude experiment using my dehumidifier on its air purifier mode with a basic PM2.5 meter placed on its top air outlet. Without its HEPA filter (required for that mode) the meter started at 33ug/m3. With a paper towel covering the air inlet, the reading dropped to 27 and with the HEPA filter inserted, the reading dropped to 25. When I tried a cotton hand towel, the reading returned back to 33, so definitely not as effective as paper towel.

Seán Byrne

The void is almost necessary, there is actually quite a lot of turbulence at the face of a fan, the void improves efficiency exactly as you said, by providing a buffer. The other thing you could consider is tapering the void towards the inlet to reduce the diameter at the inlet, think of how a venturi works, the airflow at the throttled point is much higher with no extra energy used, i.e. when you buy an axial fan for extraction, the conduit is smaller than the radius of the fan.

The Tinkering Shed

neat idea.. one thing, some of us dont have 3d printer, places like home depot (home despot), they sell popular "thin wood hobby" like 1/4x2x48 inches that would make the same type of above cage... big question - would it do well to help "corral" some of the soldier fumes?

Scott Traynor

My question is if such a tiny device would make any difference in an average sized room? The idea is great, but i suppose you would have to scale it up quite a bit to get any real benefits from it. It would be interesting to know the amount of air flowing through.

This is a great idea Clive could we have the STL file please?

Ross Clarkson

It probably wouldn't make much difference in this case, but ideally the mesh at the top should have hexagonal holes to maximise the air flow.

Stephen Pettitt

It would be great to see a smoke stream, a la Major Hardware's Fan Showdown, to visualise the air flow through the unit. Having seen those streams on regular fans, I think the void would give benefit to spread the flow across the filter, as you suggest. I would wonder how much air is actually being pulled through the filter though, or is most of the fan effect being used to pull a partial vacuum? If there's sufficient "pull" to keep a second sheet of filter/paper held in place against gravity, then it would demonstrate that the filter isn't effectively sealing the chamber, I guess. Plus would fitting an ozone generator in the void give added benefit too?

Steve Pritchard

the answer to my problem ...Thanx Clive .....

John Catterall

I think the air void is better as like you say it will provide a more even air flow. The actual design is probably best optimised for ease of printing. I have this mad vision in my mind of a spool on either side to allow easy spooling of the "paper product" across the top of the unit for ease of changing the filter. Probably UN-necessarily complex and just downright silly!

Dr Andy Hill

I made a similar item a few months ago, only I have two 80mm fans side by side in an mdf box. At the back is an activated charcoal filter. I use it to suck the fumes when I am soldering, and it works very well. I run it off my Bench power supply and can vary the speed that way. There are two Aluminium vanes on the front which pivot up and down for better control and to concentrate the suction. So Yes - it is a good idea. Bog paper is cheap.

Mike Hughes

I like it - maybe even match the grid the TP sits on to match the exact size of the sheet? Also - changing the subject to UVC :-) You have a mention in a Captain Joe video about an aircraft UVC sterilising unit by Honeywell. https://www.youtube.com/watch?v=nHLw-Nw5zQ4

Paul Kemp

I’d say fir the holes - less support structure blocking the filter (if you want max effeminacy ) and something to help stop air leaking in the edge of the sheet and bypassing it. The chamber is good and usually needed to give the fan ‘calm’ air near the blades (and vortices to disperse ) rather than near a surface where the blades / surface can interact. My main thought would be to increase the surface area even further thinking a vertical mesh drum with pleats of paper in a zig zag form (think car air filters etc) above the fan not as easy to replace the paper on but with everything design always compromises that need to be weighed.

RDM

Damn, I have to buy myself a 3D printer!!! I feel left out with all these 3D printer builds.

Mike Wynne

Just don't use any used toilet paper. You could add a drop of Olbas oil or essential oil etc to make it into an aroma fan at the same time.

evilution

Or just a frame to hold the edges down.

evilution

Yes a chamber at the top to serve as a transition between the size & shape of The fan and filter. I've heard of folks usings rolls of toilet paper in place of the filter cartridge in early [1950s] Frame oil filters. The Honeywell filter I have uses the same HEPA filter cartridge that was used for diesel trucks.

William Wallace

I would add the mesh filter on top of the paper to ensure its flat and 'sealed' to the unit. Any small air gap will massively reduce the suction through the filter.

I have an air filter unit and can confirm it's absurdly difficult to find the filters, so something simple like this is a great idea. mine has a carbon filter + hepa filter, and also has an internal UVC chamber, so perhaps if you wanted to get a bit fancier you could add in a UVC lamp :)

Blair Harrison

I made comments on the video itself. Not sure if the comment should have been here instead. Oh well.

TopEndSpoonie

Delightful in the simplicity! I like this and I want one! -On it! I will explore myself.

Michael Thompson

It sounds like you have thought this out, the plenum under the filter will help straighten the air flow to the fan (think wind tunnel), but try to eliminate any gaps between the fan and housing. And Clive, do NOT use the toilet paper that we have at work, it’s like 80 grit sandpaper! ;p

Jim Rogers

Maybe you could use this in a little glove box to make a clean room for taking hard drives apart / doing data recovery work.