Hepa+Activated Charcoal Combo

Hepa + Activated Charcoal Combo Filter Product Suggestion

A lot of printers in this area of enclosed fancy consumer printers have hepa filters (Such as the FlashForge Adventurer 4 which is close to the Bambu on price/featureset barring speed and fancy scans).

I would love to have a hepa/activated charcoal combination filter as an option to purchase bringing the X1 series up to par on the filtering front.

Even if it required a more powerful fan or had less long life this would be preferable particularly when printing filled filaments for which there isn’t much information available on their safety with regards to fine particulates.

I aware that there are some third party solutions that can be DIY’d together, but I’m not particularly interested in a bulky cobbled together solution vs one that neatly fits in and is approved by the manufacturer.


I am interested In Filtration as well. Wanting to try ABS but I am in a small space. I would love the idea of an onboard solution obviously but wondered about an activated Charcoal “bung” in a vent at the rear where the Chamber fan exits.

That might reduce to odours and with a little bit more work maybe add a Hepa above it, after the Charcoal?

Next time I pull the X1C out I will have a look.

It actually already has that.

What Im requesting is that on top of activated charcoal it has a hepa filter.


Something you need to be aware of is that although it has an activated carbon filter, it’s only for the chamber fan, which only runs when the chamber gets too hot, or when heat creep is a concern (like for PLA when running a hot bed).

For ABS prints it’s not typically switched on at all.

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Sounds like the type of thing where the fan should run at least for a few minutes after ABS prints to be useful then. Otherwise it doesnt sound particularly useful at the moment.

It’s been requested as a feature.

I agree it’s not very useful right now.

Many of us have removed the carbon filter as it reduces the effectiveness of the fan for keeping the chamber cool when printing with PLA, and it does little for ABS when it’s not running.

I have an air purifier that runs next to the printer.

there are some prints on printables to replace the carbon filter , just with a printed box instead
then you can just buy a general hepa filter and put it in there and replace the activated charcoal filter

maybe in the future they will replace the filter with a hepa filter , but the printer is also not sealed so the filter wont work for 100%
and a hepa filter does not filter any kind of odor, so i guess thats why they went for the charcoal filter instead to filter the odor out ( atleast partial )

Activated charcoal is the most effective solution to VOCs, but with ABS youll also want a HEPA. Anything else is a noise box more than a filter. Your best bet is to duct the vent outside while printing ABS.

The fan is 12v and pretty weak, so I am trying a KOTTO small extractor. It’s kind of loud and I still working on getting HEPA 13 for it, but I think this will be super helpful. I also run the Anycubic rechargeable filters inside and have them on printed stands. All in all the enclosure needs better sealing and a much stronger filtration…… I’m working on a 24v design that can be mounted on the outside and hopefully use a quite fan.

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The issue with the chamber fan, like others have pointed out, is that for those printing with filaments that generate lots of PM & VOCs (eg. ABS), this ends up lowering the chamber temp which is undesirable.

The other issue with having a exhaust fan like this is that it’s a single pass filter…which means the carbon inside doesn’t have enough time to fully adsorb all the VOCs.

There are actually papers/studies on UFPs (ultra fine particles) generated from FDM/FFF printing. Apparently the biggest protection from particulate matter (PM) is to have the machine in an enclosure. This matches what I’ve seen with some sensor testing…the enclosure blocks the majority of PMs that might be dangerous. It’s mostly the VOCs that get everywhere.

The best thing is to have an internal circulating filter. I’m currently designing one and doing a deep dive into some experiments to see how effective this is at eliminating VOCs and also to try and determine how many grams of ABS a specific volume of carbon can adsorb before it saturates.

I’ll post any findings I get over the next little while. It’s pretty mind blowing how little effort has been taken to dive deeply into this considering so many of us 3D print at home.


I imagine this could be dealt with by having the fan on low just to create a negative pressure while printing, and then turned to high for a few minutes at the end of the print.

Any links to some of these studies?

I concur. It feels a bit like we all just kinda ignore it like if we ignore it it doesn’t exist.

I do wish we had better information.

As for the internal circulation, I have seen things like the Nevermore filter systems that Vorons use.

Hi, I thought I would throw my simplistic approach to this in to the mix.
Given that I already have respiratory problems I am aware of printing PLA in a 6m x 8m room gives me a tight chest.
My method with my Prusa MK3S+ with MMU was to put it in a large enclosure with an 8 inch low flow inlet where the air is heated by a simple thermostat on a heater which heats my 6m x 8m area.
The outlet is a 6 inch fan running at reduced speed through a ‘non return valve’ recovered from a shower extraction fan which exhausts directly outside through a coupe of charcoal filters from old laser printers.
The enclosure takes up quite a bit of the room but as anyone that has used the Prusa MMU you need the space as you are in the enclose to convince one of the filaments to feed as I casually curse the thing for its orange flashing lights.

My plan, put the whole X1 Carbon in there with low flow to keep general air flow around it but not mess with temperatures.
Also add an extra couple of fans feeding outside and speed up the inlet to come on when printing is complete to purge the enclosure.
I will still use gloves and face mask when I open the door and again when I rub the surfaces down to remove dust.

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Any negative pressure is still going to pull in outside air reducing temps - undesirable for printing ABS, ASA, Polycarbonate, etc. If you’re not printing with any of those, then great. The issue with pulling air out, as I mentioned before, is that it only passes through a filter once. Carbon needs time to adsorb VOCs properly.

Don’t have the links to the studies on hand ATM - you can probably find them easily by googling.

The Nevermore filter system is a step in the right direction, but I still feel like there’s a lot of details lacking in terms of how effective carbon is, how long it lasts, what kind of flow rates are needed, etc. Will be a long journey of testing and prototyping to answer those questions for me.

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