Over 10 feet vent hose for Glowforge?

that’s a great point - i don’t worry about noise so i didn’t think about it (even though i know better from putting together my computers).


Ya its not just you that’s something people always over look or forget thats the same cfm out of a 20mm vs a 40 vs a 120 the 20 and 40 will make your ears bleed the 120 will annoy and the 240 you won’t even hear. Also the pitch of the larger fans is much nicer even if at the same sound level the pitch of the larger fans will be lower and less bleeding ears


I’m curious, what is the problem with having too much fume extraction (i.e. vacuum)?

Lighter weight materials could be sucked into areas that could effect the GF :glowforge: functionality.

I don’t know if internal hardware (fans and other components) would be effected. I think @dan has commented that the GF :glowforge: is designed for around a 200 CFM airflow.

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You can also collapse flexi vent tubing with too much negative pressure.


The two fine examples make sense. Is there anything that would affect the actual operation of the GF Laser?

There is an unanswered question that’s been floating around: Is the fan in the GF isolated so that “windmilling” doesn’t create current that could potentially damage the electronics. I don’t know enough to know if that’s even a valid concern. I’m just throwing that out there.


If you put a vacuum on the first fan you can over rev it and generate power causing back feed to the pcb


thank for reply. Here is draw.

What are you think??

That is going to work well for you.

Try to keep the 8 inch fan to outputting about 200 to 250 CFM with the 4 inch PVC.

That will keep in step with the GF :glowforge: exhaust (until you can test material that might come loose during the lasering).

Do we know if @dan has confirmed peak air flow so we can calibrate booster fans?

Here is what I found:



Great find!!!

And also a shame because its so darn loud for only 200cfm


Something to consider with putting a higher-draw fan at the end of that length of hose is the hose pressure rating to prevent collapse. You wrote down that you’re using PVC, which is fine…

But if you have a high draw fan at the end, and a weak walled dryer hose, the suction could collapse the hose in on itself like trying to suck a thick milkshake through a cheap straw.


I have a similar set up for my :glowforge: in my basement office. Appox 12 ft along the joist. I put an inline assist fan plugged into a switched outlet and it works great.


Teditz, Thank you!!. I will look for inline assist fan in website. I think it will work. Thanks, again!

No problem! Your sketch look awfully like what I have. Only difference is that I drilled a whole and you’re going to a window.
Wish you the best with it.

Where is the inline filter located? Closer to GF or closer to the window?

Do you mean the the fan?
The way I have mine set up is the flexible hose is attached to a rigid tube that goes outside. I have the fan about halfway in the rigid tube.

Yes thank you.