My experiments with GF exhaust

My current setup for the GF is to use the supplied hose, and unfortunately there are 3 different 90-bends in this hose to get to a outside window. Total hose distance is ~7 feet.

I’ve tried three solutions for exhaust from the GF:

  1. Hose out the window. Results in a lot of smoke from the unit itself as apparently its fan just can’t push through those bends and distance. Smoke is not from window area, but from around the GF. There are no hose leaks, and joints are all sealed.

  2. I bought a 4 inch computer fan ( Zhanye 120mm Fan Computer AC 1238, Axial Cooling Exhaust 110V by 125V, High Speed with Metal Net and 4-feet Power Cord - amazon). I mounted this fan in a 3-d printed fan-hose connection (see picture), and added a cleaner and more sealed port through my window. Result: less smoke, but still not clean enough. The air flow wasn’t enough through this fan. The fan was rated at 120cf/min, but I seriously doubt it was anywhere close - maybe it could without any air resistance. However, this fan did cause the off-GF’s fan to slightly turn, but not by much.

  1. I then bought a larger DUCT fan (TOPHORT Inline Duct Fan GDF100-4inch 203CFM Ventilation Fan HVAC Exhaust Blower Replacement for Grow Tent - amazon). This one is rated at 203cfm. I fitted this to my sealed port in the window and now I have very little smell from the GF. The potential downside is that if this fan is on but the GF is off, the GF is actually has a high amount of noise because the fan is pulling air out of the GF, and the poor GF fan, which is off, is spinning like crazy as air is sucked through it. I’m assuming that this is not a very good condition for the GF fan.

So, far I am satisfied with my #3 solution.


I do not think that having the Glowforge exhaust fan spinning is a problem as I have a similar Vivosun solution that runs most of the time and does pull my fan along. I did have a previous machine replaced that the fan was dead and the 200cfm Vivosun fan was barely adequate alone.

I also have a Blue-dry fan and filters that is 500 cfm and just running in the room cleans up any residual smoke or fumes. I intend for it to be the main filter eventually but it does a good cleanup job meanwhile.

How loud is the bluedri?

I’m seriously considering one. That or the Pullman Ermator A600, depending on how “quiet” one or the other is. The PE is higher CFM, but the design should be less loud.

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I would go for the higher cfm as long as it is variable. Also check the cost of filters . At full throttle and open intake you can hear it over the running Glowforge but not by much

Thanks! How loud is it at the slowest speed?

My wife is asthmatic and I won’t to get a proper air scrubber that can go in the main living space for fire season. We were miserable in the Bay Area last fall.

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You will know it is running but pretty much white sound to my tolerance is higher than squeals etc. I am also asthmatic and live by nebulizer a lot but the blue whale makes a big difference.

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Now that I look at it, the BlueDri has activated carbon filter whereas the A600 does not. I suspect activated carbon is pretty critical for smoke stench removal. The A600 is likely quieter.

Decisions, decisions.

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Activated charcoal filter would make the difference entirely for me. No activated charcoal and no fume extraction.

Didn’t mean to entirely hijack the thread.

I’d recommend sealing the inline fan. I have the same, or very similar, fan and it has some pretty significant leaks in the housing. I used gaffer’s tape to seal it up.

I also ditched the GF supplied hose as the design kinda restricts air flow already. I went with a smooth aluminum bendy dryer tube. Much heavier duty and won’t get pinholes.

At some point, I’m likely going to extend the vent up to the roof. When I do, I might go full nuts and build a sort of fume hood around the GF using both the venting solution and something like the BlueDri to cleanup residuals.


Given asthma and likelihood of summer fire smoke I would pick up a blue whale even if there was no Glowforge involved. I was getting a bad reaction every time my housemate made popcorn but the blue whale eliminated that.

If you make the box I posted elsewhere and get some of that washable pre-filter the blue whale could take care of both fume and smoke entirely without pumping your furnace heating out the vent. Though it does have a nice 6" exhaust that could send the filtered air anywhere (unlike many that just dump it on the floor)

Nice solution. I’d swap out the spring clamp for a proper worm gear drive clamp. Gives more surface area to be clamped. An I’d also throw a wrap of HVAC foil tape around it too.

That would really seal things up.

The small V8 bottles both seal tight and are quick on-off.