Air filter pointless? Exhaust & air filter combo?

According to this person, the air filter is pointless: “Air Filter- They really just need to come out and admit this air filter thing is crap. I would trust them so much more if they did. I use a laser cutter daily to cut everything from high grade rubbers and fabrics to acrylics and polypropylenes down to paper. All of it smells and some of it will make the whole office smell. We actually got kicked out of our old building because of it. And we have an air system that cost as much as the laser itself.”
(From here:


  1. Is it pretty much pointless or will it live up to the promise that one could use the GF in an office environment without venting?
  2. Is it possible to use a vent pipe together with the air filter? Point being that even the extract pipe hanging out of my office window could cause unpleasant smells for my ‘friendly neighborhood attorney’ whose office happens to be right under mine?

I’m sure there are plenty of folks here who’ve used a laser with a Purex, BOFA, or other HEPA + carbon filter attached to it. It’s fair to be skeptical and say “I’m not sure Glowforge can engineer one of these”. I’m not sure why the poster declares that it’s impossible for such a thing to exist, though.


@dan, I’d really like a more direct answer please. Is the answer to Q1: The filter should be effective in an office environment with most materials?

What is the answer to Q2?

Many thanks

1: Yes.
2: Untested.


Thanks Dan.
Q2. ‘Untested’? I meant is it the GF designed to accommodate both the filter and the exhaust simultaneously. Tested or not.

It isn’t designed for that. I can imagine jerry rigging something but have no idea if it would work.

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Ok, thanks for clarifying, Dan.
Somehow using both filter & air could be a great feature though. Might also mean a smaller pipe - 50mm or less would be much better than the old 4inch dryer duct.
I might add that to the future feature suggestions post.

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The Forge sits on top of the filter, and the duct is in the back of the Forge. So you would have to re-design the filter to have a duct coming out the bottom of it, or design a filter to set into the duct on the back.

If you are saying to have directed post-filter exhaust. If you are just saying to have the filter as well as the exhaust, then it is a matter of air-flow impedance, most of your exhaust will choose to go out through the wide open vent, rather than squeeze through the tiny pores of the filter.

@jacobturner Yup, that was the thinking.
There must be some force-venting to push air through the filters - i.e. fan(s). So I thought perhaps the cleaned air, which according to some still smell in many (most?) cases, could be exhausted. This is clearly a GF 2.0 feature. I plan to use the GF in an office environment and started this topic when I read some opinions that these filters are pretty much useless and I don’t want to find out I wasted $500 (excl shipping) on the filter - hence the query about combined use.

It would be interesting to see how the filter unit gets rid of the fumes - I mean the location and size of the exhaust grill. Or perhaps its the whole underside of the unit. I am thinking maybe we could just create a neat little chamber which we could then vent in the traditional way if needed. If not, we leave it open to breath. That way we could vent filtered air and get the best of both worlds.

Are all the units shown during the open house ducted or where some using the filter? Can we get a video featuring this add on and change our order if it doesn’t meet expectations based on demo?

I am curious too. I am on the 12th floor of an office building, can’t crack the window to let in any air.

I am concerned about this as I have a baby i bring to me basement studio with me. I purchased a pro and want to be sure that when i bring baby in after I use the laser in this space that it will be safe for him.

If you have a GF pro, I believe that is a class 4 laser product, and it is a good idea to have protective eye wear when using it. I think I read elsewhere on this site that the reason the normal GF is a class 1 laser product and the pro is a class 4 is because of the side ports on the pro.

Laser shrapnel is what happens when you shine a laser on something reflective, and it can be quite dangerous, which is why you want to be wearing protective eye wear. If you are going to have a baby (or anyone) near a GF (presumably not wearing eye protection), you might want to make sure that the side ports are completely blocked or sealed to prevent any laser shrapnel from leaving the machine. It seems like a small risk, but better safe than sorry until humanity learns to grow replacement eyeballs in vats.

Disclaimer: I am not a lawyer or laser expert, the above suggestion is just the opinion of an unqualified idiot.

Hey Dan, you want a brilliant idea for a great free community project to give away plans for on the site? Design some port covers for the pro if the GF pro doesn’t ship with them already. (Also encourage people to use them if they aren’t actively doing ‘infinite’ cuts.)

Failing that, create a pattern for a replacement eyeball…

Could we get an official answer to the question @Duality posed: does the air filtration add-on have an output vent that could be used to direct the filtered air outside? I see that as a way to protect both myself and any neighbors that are downwind from my exterior vent.

I’ve noticed at trade shows that I can smell the laser cutter vendor’s booth from 30ft away, despite the large air filtration systems they use. I personally don’t mind the wood-smoker aura, but I can imagine there are people (bird owners?) that could form a more contrary position.

The filter pack vents to the bottom of the unit. Not to a discharge duct.
The filter pack is built for 100% re-circulation (same room air), not exhaust air.

Here is a quote from Dan on 11/15.

I did ask if they might be willing to engineer a single vent option into the filter plastics, but got no response, so don’t think that is going to be there day one, if ever. It might work to place the 'Forge onto a vacuum table of sorts to suck the filter’s output out, but anything easier will likely need to wait for a 2.0. I am hoping it works better than some people are saying it will, because I simply don’t have a good way to vent this thing.

to add to @rpegg below, And both models will come with a hose so you can.

I suppose if you are “handy” you could build an enclosure around the air filter to collect the effluent and vent it (via a negative air pressure source) out the window.

Mathias Wandel comes through again. Need to rework the filtration setup but if you’d like to build your own exhaust box, here’s a good place to start.


After reading through this…I must have missed something because I’m uncertain on one thing now. I’m getting the Pro with the filter. When its in my office/manufacture room, I can vent it with my other lasers through the exhaust blower.
However when I plan to take it on site somewhere, I would need to use the filter as I wont have window access. Am I correct to assume that by installing the Glowforge onto the filter unit, it will cut off the back vent hole and force the airfliw through the filter?? Otherwise, when its not sitting on the filter, the airflow will go out the back vent…

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