Room air filter for solder smoke?

[Faringdon]

Hi,
I am soldering in  a small enclosed room, whose door leads out only to a small corridor, enclosed by fire doors which must be kept shut.  There are no windows. I have fans to blow the solder smoke away from my face. However, also I need to filter the room air. I was thinking a 5 inch inline duct fan and some 5 inch ducting…just leaving the duct and fan on the floor, and have like a big cigarette filter in the other end of the duct, so the room air gets  gradually cycled through the filter. Can you think of a better way, also cheap?
Do you know of such filters?

[Psi]

See if you can find some large replacement air filters for some other product on the market that are affordable.
Then build your own enclosure around it with a large blower fan.

The filters for proper solder fume extractors are usually quite large to get the airflow without needing crazy loud high pressure fans.
Sort of in the range 30cm x 10cm x 20cm, that sort of size

[KungFuJosh]

What you're looking for is usually referred to as a solder fume extractor. There are a variety of them, not many of them are very good though. Typically the extractor part (usually a fan or vent hose) needs to be placed very close to the soldering area to have any effect.

If you want to go more effective/overkill you could look at laser fume extractors like the OMtech XL300, or something less effective but still probably good enough for soldering like this: https://www.amazon.com/Monport-Purifier-Extractor-Engraver-Material/dp/B0BJF4BKFK.

[Fungus]

Kitchen extractor blowing into one of these: https://www.aliexpress.com/item/33010913122.html

I'm not sure how many microns are needed for solder fumes. Anybody?

[arvidb]

(The darn editor ate my post - here's a short version)

I made this fume extractor long ago. It's using an F7 filter, filter area ~250 cm². I have since mounted the filter box to the underside of my workbench and drilled a hole though the table with a flange on the top of the table for the ⌀100 mm hose to attach to. The inline fan is just sitting on the floor, venting into the room with no ill effects. Seems to work fine - and I'm very sensitive to smells!

The "input end" needs to be rather close to the work to be fully effective, perhaps 10 cm or so. It also makes some noise so I turn it on only while actively soldering.

[donlisms]

I tried to learn about these things when I was setting up dust collection for my wood shop - same problems, pretty much.  There is something called "capture velocity," which I think is when the energy of the air overcomes the energy of the moving particle itself. Of course smoke particles are much smaller than wood, but still...

When I ponder fume extraction, it seems like it works inefficiently because the air velocity falls off so rapidly as we move away from the vacuum inlet. We go from, say, the cross-section of a 100mm tube to a cross-section of the open space, meters, and the velocity is reduced by that ratio.  Thus... "has to be very close."

So it seems to me the way to make it work would be push-pull, where you can have a directional small-diameter flow across the work area, and then have a receiving vacuum inlet on the other side.  If the receiver is large enough to cover the expanded air stream, the capture happens at the surface of the inlet, where the intake velocity is still high.

And when I say "vacuum", I mean something like a fan pulling air through a tube. And the gentle air source doesn't need to produce hurricane winds, either.  Anyway... just some thoughts.  A couple fans, some tubing, a HEPA filter.  Maybe only one fan, in a loop.

[thm_w]

We have many threads discussing this already in the correct forum section here: https://www.eevblog.com/forum/reviews/

Yes, duct, duct fan and HEPA filter at the end is going to give you the best result for the lowest cost and let the fan noise be further away from your face.

https://www.eevblog.com/forum/reviews/fume-extractor-advice/
https://www.eevblog.com/forum/blog/eevblog-1305-hepa-solder-fume-extractor/
https://www.eevblog.com/forum/reviews/solder-fume-extractor-advice/
https://www.eevblog.com/forum/projects/homemade-hepa-solder-fume-extractor/
https://www.eevblog.com/forum/reviews/solder-fume-extractor-filter-inserts/

[RiRaRi]

Hello. I searched for good and proper but not-so-expensive fume extractor. It needs to have 3 filter system with active carbon to properly extract fumes. Check this out. It has two hose. I would use one for soldering station where you put iron after soldering and one for soldering. This is cheapest but proper and powerful extractor.
https://eleshop.eu/aoyue-fek-01-portable-soldering-fume-extractor.html

If anyone can give a review about it it would be helpful to all of us

[aeberbach]

Can you 3D print? Find the most economical filter cartridges with the desired attributes (filtration, availability, price) and print a thing that mates with your duct and lets you easily slot in a filter.

[KungFuJosh]

Hello. I searched for good and proper but not-so-expensive fume extractor. It needs to have 3 filter system with active carbon to properly extract fumes. Check this out. It has two hose. I would use one for soldering station where you put iron after soldering and one for soldering. This is cheapest but proper and powerful extractor.
https://eleshop.eu/aoyue-fek-01-portable-soldering-fume-extractor.html

If anyone can give a review about it it would be helpful to all of us

Aoyue has other options too: https://www.amazon.com/Extractor-Benchtop-Soldering-Powerful-Activated/dp/B0B58527PT

My soldering station is from Aoyue, and it's great. I'll probably buy one of those extractors so I can get rid of the one stuck to my iron.

[Faringdon]

Thanks, the cheap solution, as  hinted kindly by thm_w looks like the attached, i believe.

1...Have 2 fans on the bench to disperse the solder smoke away from your face.
2....Then an inline duct fan on the bench, blowing air into the duct, at the other end of the duct you jam it with filter material like wool etc.......and that will just gradually clean the room air.
Any good?

[thm_w]

I'm fine with just the one fan and duct, no secondary fan on the desk, but depends on your preference.
The items you list are.. ok not great. Ideally you have a proper HEPA filter (similar to what arvidb shows) instead of just cotton that won't really catch anything.

The problem is you have to adapt the filter on the end of your hose, and usually they are square sizes which is not easy. Cardboard or posterboard can work.

Ideas:
https://www.amazon.co.uk/Amazon-Bascis-Purifier-Replacement-Filter/dp/B09W9JV3KJ/
https://www.amazon.co.uk/kalado-Purifier-Filter-KCA02-High-Efficiency/dp/B0BZ8938SN/
https://www.amazon.co.uk/DeLonghi-Replacement-Filter-Purifier-ACF-2/dp/B00CPDZ3TI/

[sebyon]

Kitchen extractor blowing into one of these: https://www.aliexpress.com/item/33010913122.html

I'm not sure how many microns are needed for solder fumes. Anybody?

Good on you for taking this seriously.

Solder fumes are typically between 0.1 to 1 micron. The nasty part would be the volatile organics from the flux. A HEPA filter will capture the particulate matter, while you'll need an activated carbon filter to neutralise the volatile organics from the flux. 

The best thing to consider is how much soldering you're doing, and how confined your workspace is. While off the shelf and DIY units would do little for filtration and neutralising, having airflow pushing it away from your respirable zone would drive down your exposure. If you're doing a lot of soldering, I would look at commercially made units with both HEPA and carbon filters.



 

[Faringdon]

Thanks, i have looked into some HEPA filters to put round the exit of the duct.

Also, i wonder if this el cheapo humidifier at £20 would do some good.....it puts water vapour into the air,  and i wonder, if the water vapour may catch hold of the rosin flux particles, and lead solder particles, and stick to them, and make them fall to the floor?

Humidifier:
https://www.amazon.co.uk/Portable-Purifier-Humidifier-adjustable-Suitable/dp/B09BL533YJ/ref=sr_1_18_sspa?crid=3UJM29IGUP6QB&keywords=HEPA%2BFILTER&qid=1695482793&sprefix=hepa%2Bfilter%2Caps%2C81&sr=8-18-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9idGY&th=1

i am actually wondering if a kettle, with water being brought to the boil every say 10 minutes, and emitting steam into the air, may also have such benefit?

___---___
Then there's this, for £33 and the HEPA  filter is £12 on top of that...
https://www.amazon.co.uk/dp/B0BGN5GTG4/ref=twister_B0BKJGFDY6?_encoding=UTF8&psc=1

__--__
Then there these £10 HEPA filters which could be cut into 5 inch diam discs, and put into the 5 inch ducting with the fan at the other end?

https://www.amazon.co.uk/HQRP-4-pack-Bionaire-Purifiers-Coaster/dp/B01GQBJ70U/ref=sr_1_3?crid=7FPRPZXTTFDW&keywords=5+INCH+HEPA+AIR+FILTER&qid=1695484005&s=kitchen&sprefix=5+inch+hepa+air+filter%2Ckitchen%2C72&sr=1-3

___---___

Then theres just ducting the room air to one of these £26'ers placed on the ground..say 2 metres away....that way, you will be assured that the entire room air goes through the filter at some point...rather than just using the solder fan filter on its own..

https://www.amazon.co.uk/Soldering-Absorber-Remover-Extractor-absorbs/dp/B0CH9W1SFQ/ref=sr_1_1?crid=1E5ILSPJUN8EN&keywords=solder+air+filter&qid=1695484775&sprefix=solder+air+filte%2Caps%2C81&sr=8-1

[Jackster]

I used to use these to filter out smoke from soldering and laser cutter in my shed back in the day.
https://amzn.to/3PuIRxl

They work great. Just a wooden box with a HEPA and activated carbon filter with a decent 12V NIDEC server fan in it.