Which air purifier to use (if any)?  

RE: Which air purifier to use (if any)?

I personally wouldn't (and don't) bother with filtering for PLA, PETG and polycarbonate.

ABS, Nylon, etc are a different story. They give off some pretty nasty VOC's when melted.

There are a few off-the-shelf options or you can build your own. Chris Riley of Chris' Basement on YouTube did a good review on one recently. 

If you don't print in an enclosure, you'll have a hard time doing anything tangible. That said, If you want to move to the filaments that should have filtration for VOC's, you'll want an enclosure anyway to get successful prints.

RE: Which air purifier to use (if any)?

I think a room air filter is a good idea in general. From what I've read, a good HEPA filter will remove most of the emissions of concern, provided you maintain the filter. It's not going to capture ALL UFPs, but I'm usually printing with PLA or PETG so don't have a lot of concerns. It definitely helps with the other UFP-generators like laser printers and computers in my office. Keeps the air smelling fresh too, and the UV filter gets rid of some bad stuff. In short: Unless you're going all out on a proper filtration cabinet for your 3D printing, a good HEPA filter is a good compromise.

RE: Which air purifier to use (if any)?

Thank you so far for the suggestions!

I print as a hobby, so the amount of printing is not that high. However, the printer is right next to me on my desk, so I'm sitting right next to it.

I think that when printing other materials (not PLA), I will probably do that in the evenings or the weekend, when I'm not sitting next to it.

About the enclosure, I don't plan on having one, but would it seriously affect the printing with those other materials? Are they super sensitive to temperature changes?

RE: Which air purifier to use (if any)?

Posted by: @sprocket314

[...] About the enclosure, I don't plan on having one, but would it seriously affect the printing with those other materials? Are they super sensitive to temperature changes?

It really depends on the material. For ABS, an enclosure is essentially required. Other materials may experience warping with larger prints. In addition to containing fumes, the enclosure can also stabilize temperatures.

RE: Which air purifier to use (if any)?

I'd also add that "PLA/PETG is strictly safer than ABS" is sorta a common myth. There're quite a few scientific papers showing that:

1) concentrations of emissions really depend on the filament composition, not just the blanket type of it - things like colors, manufacturer (and even a given batch!) significantly affect the overall "fume footprint"

2) the size of the particles is smaller for PLA, and as such may be considered more dangerous, as it can penetrate our tissues more easily. So some papers even considered PLA to be more dangerous than ABS, for the particles at least (VOCs still tend to be greater for ABS, though).

So really any material requires an enclosure, unless you keep the printer in a well-ventilated and unpopulated area.

Workshop

There are few scientific studies if any to show actual harm from printing ABS, but do you want to take the risk.  I recommend an enclosure and HEPA filter if you are going to use it in your home.  The problem with an enclosure and PLA or PETG is you can get heat creep.  I would vent it outside and have some way to keep the temp down in this case.  Me, I just print in a workshop.  

Posted by: @dinvlad

I'd also add that "PLA/PETG is strictly safer than ABS" is sorta a common myth. There're quite a few scientific papers showing that:

1) concentrations of emissions really depend on the filament composition, not just the blanket type of it - things like colors, manufacturer (and even a given batch!) significantly affect the overall "fume footprint"

2) the size of the particles is smaller for PLA, and as such may be considered more dangerous, as it can penetrate our tissues more easily. So some papers even considered PLA to be more dangerous than ABS, for the particles at least (VOCs still tend to be greater for ABS, though).

So really any material requires an enclosure, unless you keep the printer in a well-ventilated and unpopulated area.

Vent outside

my understanding is that a hepa filter catches nothing of interest from a 3D printer.  Hepa filters catch dust, dust mites, pet dander, pollen, cigarette smoke particles, etc.  a charcoal filter will catch some of the nasty stuff coming off of abs, and the occasional beer fart.  Do note that not all charcoal is the same, and at some point, if not often changed, it will puke back what it captured. 

If you are really concerned about emissions, park your printer in a far corner of your home, in an enclosure, and if possible, vent to the outside.

think of filters on your printer as filters on a cigarette. 

RE: HEPA filter

It depends on the filter.  It it has a charcoal file with the filtration, it can help with VOCs.  I use mine to pull air out of the enclosure.  It prevent overheating and pushes the lingering fumes our a drier vent.  

? Really?

You filter air, HEPA and/or charcoal, before it goes out the dryer vent?  The filter prevents overheating and serious fumes?  That is one serious beer fart.

A HEPA filter does nothing to capture particles of concern coming from a 3d printer. 

UFP is small.

https://en.wikipedia.org/wiki/Ultrafine_particle

HEPA doesn't capture that small.

https://en.wikipedia.org/wiki/HEPA

Charcoal, which is not all the same, can capture some or much of the nasty fumes coming off of some filaments like ABS.  But, be thoughtful about choosing and changing the charcoal often.   But, it only captures some fumes not particles.

If you are venting to the outside, just run the fans and call it a day.  Prolly the best answer.  Not there yet, but that's where I am going.

Hepa

My HEPA filter has a layer of charcoal then a Hepafilter.  It pulls the hot air our of the top of the enclosure and replace it with cool air (at the top).  It still allow draft prevention and avoids warping with ABS and keeps the fumes (smell) out of my apartment.  I am moving my printers to a new workshop on my farm.  I will keep using them there.  

I did use a standard HEPA prior and it did “something”.  It is easy to say the HEPA does nothing, but my nose knows differently.  

Posted by: @eric-e

You filter air, HEPA and/or charcoal, before it goes out the dryer vent?  The filter prevents overheating and serious fumes?  That is one serious beer fart.

A HEPA filter does nothing to capture particles of concern coming from a 3d printer. 

UFP is small.

https://en.wikipedia.org/wiki/Ultrafine_particle

HEPA doesn't capture that small.

https://en.wikipedia.org/wiki/HEPA

Charcoal, which is not all the same, can capture some or much of the nasty fumes coming off of some filaments like ABS.  But, be thoughtful about choosing and changing the charcoal often.   But, it only captures some fumes not particles.

If you are venting to the outside, just run the fans and call it a day.  Prolly the best answer.  Not there yet, but that's where I am going.

RE: Vent outside

my understanding is that a hepa filter catches nothing of interest from a 3D printer.

That's a common misconception, my friend. There's a well-known study form NASA that shows that in <0.1um regime HEPA actually has even better efficiency than above, due to diffusion. So it's a common misunderstanding how filtering works at that level - the physics of it is not quite the same as for a kitchen sieve 🙂 A few recent studies (for example this highly cited one) have even shown this for the particular context of 3d printing. There's slightly less efficiency around 0.3um, but still.

It is true however, that HEPA doesn't efficiently capture VOCs - those need to be done by activated charcoal. Unfortunately, it appears that while it captures VOCs efficiently, there needs to be a lot of it and it needs to be monitored since it can kinda get inactivated easily, if not careful.

So my main concern at this point is actually not UFPs, but VOCs. They are harder to contain even in a seemingly fully-sealed enclosure, as gases can creep through the tiniest of gaps. Printing PLA/PETG can help, but even that really depends on the filament impurities and temperature, so the best unfortunately does seem to be venting outside with a more powerful fan than my ears want to tolerate. So I'm inclining to wait to get my Prusa until next year, when I can move to a place with a basement where I could install one.

fumes

Either way, I am sure my process eliminates enough of the stuff to make less harmful and it definitely make it more tolerable.  I cannot even smell the filament anymore.  It definitely reduces heat creep without inducing warping.  

Posted by: @dinvlad

my understanding is that a hepa filter catches nothing of interest from a 3D printer.

That's a common misconception, my friend. There's a well-known study form NASA that shows that in <0.1um regime HEPA actually has even better efficiency than above, due to diffusion. So it's a common misunderstanding how filtering works at that level - the physics of it is not quite the same as for a kitchen sieve 🙂 A few recent studies (for example this highly cited one) have even shown this for the particular context of 3d printing. There's slightly less efficiency around 0.3um, but still.

It is true however, that HEPA doesn't efficiently capture VOCs - those need to be done by activated charcoal. Unfortunately, it appears that while it captures VOCs efficiently, there needs to be a lot of it and it needs to be monitored since it can kinda get inactivated easily, if not careful.

So my main concern at this point is actually not UFPs, but VOCs. They are harder to contain even in a seemingly fully-sealed enclosure, as gases can creep through the tiniest of gaps. Printing PLA/PETG can help, but even that really depends on the filament impurities and temperature, so the best unfortunately does seem to be venting outside with a more powerful fan than my ears want to tolerate. So I'm inclining to wait to get my Prusa until next year, when I can move to a place with a basement where I could install one.

Re: fumes

@cwbullet I hope you're right! Out of curiosity, which enclosure did you use and which filter(s)?

smell

I have a custom enclosure made with lack tables but a tighter seal.  I use a wind silicone seal to close the gaps between acrylic panels and table. I would not try to use it as an aquarium or paint booth because I am sure it far from air tight, but with the venting, very few smellable odors escape.  

I am a physician and expert on occupational medicine and OSHA and I am not worried about the fumes but I would prefer not to smell them.

Re: smell

I am a physician and expert on occupational medicine and OSHA and I am not worried about the fumes

OK wow, that's a relief to hear! I've heard some folks saying that the printer fumes are nowhere near the "norms" for injection molding facilities (and even those are within the limits). But on the other hand, some papers claim 20x excess relative to the "norms" (though probably mostly for ABS). So I'm really not sure which sources to believe ¯\_(ツ)_/¯

RE: Which air purifier to use (if any)?

We are using Shark HE601 Air Purifier. I literally did not know how bad I needed this product.. Now is a staple item in our household.

Pros:

• Easy read-out showing current Air Quality

• Auto Fan setting – Adjust fan speed based on the air quality. Burn that popcorn in the microwave, this gem will sense the air quality change and adjust up the fan speed to clean the air

• Super simple initial set up. Just unbox, find a spot for it, and plug it in. The controls on the unit and the remote or user friendly.

• Noticeable difference in air quality: o Less sniffling from pollen. o No longer have to smell dinner for hours o Pet smells are under control

Cons:

• Not really a con with the unit or its operation, just more of a gripe. Had issues with the QR code on top of the unit. It pulled up the user guide but I could not access any of the websites radio buttons for additional content.

RE: Which air purifier to use (if any)?

@annieclo - I think an air purifier would certainly help removing particulates, but I'm not sure it does anything for VOCs. Granted with non-resin printers VOCs are less of a problem..

RE: Which air purifier to use (if any)?

I understand your concerns.  It is a real worry, but I do not think it will cause problems unless you live beside the printer in a small closed environment 24/7.  

Posted by: @dinvlad

I am a physician and expert on occupational medicine and OSHA and I am not worried about the fumes

OK wow, that's a relief to hear! I've heard some folks saying that the printer fumes are nowhere near the "norms" for injection molding facilities (and even those are within the limits). But on the other hand, some papers claim 20x excess relative to the "norms" (though probably mostly for ABS). So I'm really not sure which sources to believe ¯\_(ツ)_/¯

RE: Which air purifier to use (if any)?

I printed my own filter use a tea bag style fish tank activated carbon filter. I’m just moving the printer to its final box and the filter has been on all 3. The low volume of the 80 mm fan through the dense charcoal does not upset the ASA I typically print with. I printed an 80mm to 3” adaptor and a hose goes yet another window box with another 80mm fan to keep air clean around my airbrush. If it’s PLA I may leave the door open or cover off. The filter then stands alone. 

So far so good. And the charcoal is cheap