Filter and in-line fan

I have searched the forum, and I’m sure the question has been asked, but I didn’t see what I was really looking for: I want to get an inline fan and a filter that will reduce the smoke I’m piping into the neighborhood. Does someone have recommendations? I’ll be venting out a dryer-vent type hole in the wall near my unit.

Thanks for links to old posts or any advice.

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There have been lots of discussions about in-line fans, but not quite as much about filters. You can start here: Search results for 'inline fan' - Glowforge Owners Forum


Another possibility is to pipe it up.

@dwardio did that and may have some feedback about the concentration of smoke at ground level.


Thanks, I’ve done this.

Thanks, that’s a good idea. My studio will be on the second floor. We are remodeling so I’m a bit flexible. @dwardio do you have any comments about it now? How’s it holding up?

I am pumping out a window into an open carport. I expected that there would be a lot of smoke but the reality is that very little smoke is actually expelled.

The next house is 10’ beyond the carport, and they spend a lot of time sitting out smoking cigarettes but I get more of their smoke than they do of mine.

Since installing my vent system, I’ve never had any odors at ground level, nor does it expel any visible smoke. I’m 100% satisfied with the setup.


Cutting wood produces tons of smoke, and depending on where you are that can be not okay. I have a HOA that has a no visible smoke rule so I can’t risk it. I did a few attempts at making a filter before ending up with a BOFA unit. It’s hard to get an inline fan that will pull enough air through a filter to keep the smoke out of the unit. You need a filter with a MERV rating of 13-14 to clean the visible smoke out and a final CFM rating of ~200 after adding the filter. Most of the inline filters you’d be able to get from amazon are only going to result in 70-100CFM after adding the filter inline. For ongoing costs getting a professional filter with separate pre and HEPA/charcoal filters is the cheapest option. If you only care about the smoke part you’ll replace pre-filters but almost never need to replace the HEPA/charcoal filter (which is the expensive part).

My personal setup is this Glowforge with exhaust fan removed (it’s loud just spinning when turned off) > BOFA unit > replaced the exhaust plate on the BOFA to make it output to a 4" duct > vent through a 3d printed adapter which converts the 4" duct to a window vent (12" x 1").



D’ya think?

Thank you, that’s very helpful!

I do not cut any MDF, and Oak ply rarely. Only once has anyone reported smoke and that was cutting Oak. Cutting Acrylic is a different matter. There is hardly any smoke but it smells strongly. The people next door only smoke cigarettes outside and their smoke is far more noticeable than mine.

Also this…

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There’s a huge market for high flow charcoal canister filters driven by the demand from indoor (mostly illicit I expect) grow operations. Do some searches for “grow room exhaust filters”. If they can capture the smell of pot plants, they ought to be able to capture what comes out of a laser cutter.

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Thanks, I’ll check that one out. I don’t think I’d spring for the BOFA system you have unless I get complaints. I do cut wood, but not constantly. I’d rather not bother the neighbors enough for them to notice that the smell and start questioning where it’s coming from, though. I think I’m going to go with the inline fan to help me with noise and smell indoors, and hope for the best. If that doesn’t work out, I’ll explore filters more.

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I have one of those canisters, it came with the first fan I bought.

They don’t reduce smoke at all, but there isn’t enough to worry about. It dissipates immediately in open air. I scrapped it years ago.

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Lol I think those are carbon filters. To get the smoke, I’m pretty sure HEPA filters are the way to go. I’m going to go for the “it dissipates immediately” theory for starters. It’s are not all that close to the neighbors, since our detached garage is between, and this vent will be upstairs, which should help. I might even put it up high on the wall to encourage it.

I would be amazed if anyone would smell it, or even had a clue where it came from if they got a moments whiff. The same volume of smoke will already be dispersed before leaving the Glowforge if the final volume of air moving through the the machine is tripled. So much so it does not even get as dirty.

I use an in-line fan and filter system, currently still venting out the window but am trying to dial it in to be able to clean and circulate air in an enclosed space.

From what I’ve come across, the charcoal filters only filter fumes, etc and one needs a HEPA filter for specially smoke.

Where are you in your filter build/journey? I have the 6” AC Infinity in-line fan and got a 6x18 charcoal filter, I think the equipment is similar to a grow tent setup. I would like to size back down to a 4” charcoal filter, but want to try and incorporate a HEPA in there. Before or after the charcoal filter? I’m mostly cutting wood (smokey!) so I’m not terribly concerned with fumes at this point.

I’m trying to get used to this communication board method, but I have a lot of questions and don’t know where to put them!

I hope it’s going well! Let me know what you’ve figured out!
Thank you!

-inquiring minds want to know

I bought one of these…

But if you just made a wooden box that could hold the filters, and put the infinity fan on the exit side you would have pretty close to the same.

has anyone ever passed the smoke exhaust thru an ionizer that would make the particles ‘heavier’ and fall to the ground, maybe a collection area under it? i’m just spitballin here…