Air Filter Latest

@dan Can you clarify the duct size for the new compact filter? Regular 4" dryer vent?

And is the inlet on the back or top? Trying to configure the right space for the cutter in our school makerspace.

Thank you so much! I was trying to search the forum, but didn’t find this. I appreciate your patience & answering the questions again!

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Not Dan, but I have one of the filters…the inlet is a standard 4" dryer hose connection and the connection is on top of the filter.

Pictures Here:
(I’m using a quick connect setup to switch between venting outside and using the filter.)

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Thanks so much for the quick response @Jules. Do you know if you can lay the filer on it’s side and still operate correctly? I’m trying to place this thing in a cabinet and would really like it to it pull from the back (not top) of the cabinet.

Well… I don’t know. :thinking:

The air outlets are on the sides of the box and you wouldn’t want to block them. (They require a couple of inches clearance on either side.) The power switch and electrical connection are on the back of the machine and the dial control for it is on the front…so no, there isn’t really a free face on the box that isn’t in use. :neutral_face:

That is great info…sounds like the answer is no.:wink: Thanks for the intel

Well said! I will wait as well. Keep working Dan! I know you guys could do it.
It’s only been 4 years for me.

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I have a Sentry Air Systems chemical hood air filter that is plenty good for removing smoke from something like the Glowforge however the draw on the Sentry is slower than the fan on the Glowforge.

Can I throttle the fan on the Glowforge to use the Sentry air filter until the GF filter is avail? You indicate that a switch will be avail in the SW.

Can I use this this to balance the output from the GF with the intake of the Sentry?



I believe they are planning to turn the switch on for everyone eventually:


I’m just here to confirm that everything @jules said so far in this thread is, unsurprisingly, correct. :slight_smile:


@Jules what can you tell me about your prefilter? (brand?) Or if you know what brands others are usin? I was planning on ordering a BOFA prefilter today since I burn through a carbon module in my BOFA filter in 6-8 weeks. (should last 4-6 months)

All I can tell you about it is that it is manufactured by Glowforge, and that for replacement filters on this one, we need to send an email to
(It’s early days yet, they’ll probably eventually show up in the Store.)

Mike, are you burning through a lot of cheap MDF or Draftboard? If you’re burning junk wood, you’re probably going to fill up that filter over ten times faster (it’s what the Glowforge team has found, and verified by my testing with the Prefilter).

A Prefilter might definitely help with that. Anything to knock out the larger particles. The other thing that I found that was problematic was anything resinous. (Pine, Cedar, Padauk) That tends to gunk up the filter reducing airflow.

Sometimes it just winds up being the physics of the thing, and you might find that buying better material that doesn’t load up the filter as fast turns out to be more economical in the long run. Or try the prefilter. It’s worth a shot. :slightly_smiling_face:

The pre-filter is GF too? Is it a separate in-line unit? If so I must have missed talk of that.

I don’t do any draftboard. The occasional sheet of 1/4” MDF that I buy from a local lumber shop, but that’s maybe a sheet or so every 2 weeks. Otherwise it’s all just cast acrylic.

Oh no, I’m sorry…I completely read that too quickly. The filter was Glowforge. The prefilter was hosiery.

L’eggs I believe. :wink:




Good to reiterate that where the pre-filter does really well in this case, it does get clogged rather quickly from the same woods that would fill the filter itself, and can be dangerous if not tended to often.

So if you’re going to pioneer into your own pre-filters like our beloved @jules, here, then please be very careful and cautious. Saving money is great, but when it causes the more expensive stuff to break, or harm to come to you or those around you, it’s not worth it.

I don’t have this filter, and I can’t speak from experience, but it’s just a cautionary post so that the wild eyed readers don’t get out of hand, and then blame GF for allowing them access to put something obstructive into their filter through their own choices :stuck_out_tongue_winking_eye:


Oh yes, absolutely kids…do not try this at home. I was testing this with full face mask breathing protection. That fine acrylic dust is not something you want to have floating around.

As a matter of fact…in the interest of not having people duplicate that experiment, I’m going to delete that post. Thanks @raymondking32.

(They don’t need to know how the sausage is made.)


I’m glad I saw the pics…ordering my pre-filter right now! That’s crazy!

@dan Can you give us the schedule you’re expecting for people who signed up to know whether they’re selected or not? At least some way to confirm we successfully filled out the form?

They said a couple of weeks for the first production run at the bottom of the sign-up sheet.

(That might be two weeks from the time that they get a full run’s worth of filters though, so I wouldn’t freak out if it’s a little longer. I have no idea how many it takes to justify a production run.)

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