Would this be efficient enough if I scaled this up to like a large pail and added a fan?
Yes, what @spike said. The proper layering of materials really shouldn’t be what those shop videos were doing, and more along the lines of this:
GF output -> Polyester fill (correction: Polyester batting) (available in flat rolls from quilting or fish supply stores) -> Carbon pellet layer -> HEPA filter -> Exhaust fan.
I’ll probably wind up just making a little ‘polyester bag’ with hotglue, filled with carbon.
If you’re not getting any amount of breeze at all (or very little) from the fan, then chances are you’ve packed the carbon too densely. It’s better to use more loosely packed carbon than it is to use less of tightly packed carbon.
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Speaking of “bad gasses”, if you do go with the make-your-own carbon filter approach… use ACTIVATED CARBON (aka activated charcoal). Don’t use plain charcoal/carbon. The ‘activated’ part of it comes from the treatment used to improve the absorption aspects.
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Suppper helpful!!! Thank you!
How often should the carbon be changed? If at all.
Depends on use
You can tell when it stops working
Smell just starts coming through
These are also a good quick way to go
https://www.discountfilters.com/air-filters/16-25-1-carbon-air-filter/p175084/?utm_source=google&utm_medium=Product_Search&utm_campaign=google_base&dc=he29e&gclid=CKqwmeq4r8oCFQdafgodiTQGJw
I have have very good luck with reducing odors with them
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Oh!!! That’s amazing!! Thanks for the link!! That’s great.
Is there a detector (like a smoke detector style) that could be used as a precaution?
For smell? Not that I know of, there are some for gases, but that is a overkill.
If you’re going to get into gas detection, that’s a whole different ballgame.
http://www.rkiinstruments.com/?gclid=COH3tta6r8oCFUNhfgodpF4I1A
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Not really. You’re best to set yourself up a schedule of either “so many hours of lasing” or “every three months” (typical furnace filter replacement times).
With the home-made carbon filter approach… 3 pounds of carbon will last for a long time, so you could do it more often.
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Ok, thanks guys. I’m new to this game and don’t want to die. Haha. 
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There are aspects of that video which are good. It looks nice, but it doesn’t look incredibly serviceable on a regular basis when you need to replace carbon AND hepa filters.
You would definitely have to add an additional fan to draw out the air. You don’t want any back-gassing from increased pressure to wind up in the hopper of the GF.
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I buy my MERV13 filters from those guys for our HVAc and they have always been super reliable and with excellent costumer service.
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Yup. agree
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Yeah I am setting up a dual CNC & Laser machine small Workshop. The room-based air filtration is to be for any particulates the CNC generated, mostly.
Will vent my GF outside, or use the filter sparingly.
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Good advice. I wonder whether the Glowforge filter unit breaks this rule. Isn’t the fan in the Glowforge itself, so the filter must be on the discharge side of that? Perhaps it doesn’t matter if it is well sealed.
There are fans in the filter unit as well. How they oriented we don’t know. I thought I remembered a wattage for the filter unit but can’t find it right now. I did find where Dan said the following: [quote=“dan, post:2, topic:289, full:true”]
Yes, and it’s easy to switch. If you have an convenient outdoor exhaust I’d do that - it’s a little quieter without the extra fans.
[/quote]
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Okay, this topic has managed to get me fired up enough to crack open Sketchup and pull something together. I’ve been trying to find an interesting project to learn it more, and this is just about as good as any.
My pen & paper sketch is very loosely in the area of 14" long x 5.5" wide x 12" tall, and should accommodate a fan with optional secondary fan, so a person could tweak it to CFM capacity or noise levels.
Bonus: should be cuttable on the GF when it arrives. lol
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We would love to see what you came up with!!!
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There’s significantly more fan power in the filter than in the GF. Further the fans are separately controlled and driven by the motion planner, so we can optimize the airflow between the GF and the filter.
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@dan, The neat thing about that is you can do material based filtration. For materials that aren’t particularly toxic and produce little in the way of fumes (chocolate? Nori?) you don’t use up your filter and stay quiet, while for nastier stuff like acrylic or anodized aluminum you can filter more…
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