Extend Exhaust Hose with In-line fan?

Hello. Finally getting around to installing my GF after dealing with the business of having a baby :slight_smile: We are locating it in the basement with typical small windows up by the ceiling. I’d like to locate the machine about 12’ away. To account for the additional length and the upward climb to the window, should I add an in-line fan? I have a few laying around and wonder if the fan is too strong would it pose a problem for the operation of the laser? Thanks in advance for your help. can’t wait to get up and running after looking at the box for months!

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I added an inline fan just to cut down on some of the smell and add a little push to the :glowforge: fan. It has worked wonders.

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I think and additional inline fan is always a good idea. in addition to helping with a longer exhaust line, you can leave it running for a while after a cut (the internal fan shuts off a few moments after the cut) to continue to air things out.

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I too wonder if it would hurt having fan that’s too strong?

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My big concern is the CFM of the fan. I have a few laying around from small to very strong. I worry that the draw from the fan will be so strong it will impede with the laser or the function of the machine. Has anyone tried? Any info greatly appreciated. Off to Home Depot this morning.

Awesome! Thanks…these photos are a big help. What CFM is your fan? This looks like just the setup I need.

The GF fan is around 200CFM we are told, so I think it is best to be close to that.

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I am using the fan (without the filter) from this:

https://www.amazon.com/dp/B00D7M6692/ref=cm_sw_r_cp_tai_-2vOAbP8KFDYS

I run the stock 8’ :glowforge: hose into this fan and then from it an additional 20’ hose out through the sliding glass door and into the back yard. Seems to be working without any issues.

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I took a look at what I have and it seems the smallest I have is 863CFM. :-o

Many people have tried. It’s all over the forum. One of the things to watch out for is that most fans are not sealed and smoke will leak from every seam.

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I got one off of Amazon - Diameter: 4 inch; Air Flow: 100 CFM; Speed: 2930 RPM; Voltage: 110/120V; Wattage: 12W; Noise Level: 40 db. But I’m rethinking I need a higher CFM based on @palmercr recommendation. I’m going to do a little more research.

https://www.amazon.com/gp/product/B00CQBFOTS/ref=oh_aui_detailpage_o04_s00?ie=UTF8&th=1

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I’m using this booster fan: https://www.amazon.com/gp/product/B00AL0DJNY/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

It’s 200CFM, because I was trying to match what the GF had. I used 4" sewage pipe for my 10’ run. I do have 4 turns (2 90° and 2 45° elbows) .

When you open the lid, you can feel the booster fan air sucking inside the GF.

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I’m using this same fan now.

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Did you ever order this particular fan and install it? I’m curious if just a little booster will work well enough for my needs and this is well within budget.

I’ve just been using the built-in exhaust and run the vent straight out a window through the length of the tube. It’s been a little shy of okay - only a problem when I cut acrylic and the fumes linger. I don’t mind the smell of wood smoke as much.

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Yes, this is the one I have in my photos. I have it plugged into a surge protector along with the :glowforge: and a air purifier from Home Depot. The fan and the purifier come on when I turn on my :glowforge:. It works great. I set it up because of the problems with cutting acrylic and the fact that I have it in the basement off of what we use for a family room. The little boost from the fan really helps with smells and smoke.

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Perfect. I also run an air purifier when cutting and acrylic is what bothers my husband the most.

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For 12 feet, I would install a booster rated around 190 CFM. Best configuration would be to mount the fan as near the end as possible, like right at the window. Any of the run that is downstream of the fan will be pressurized - so every seam will be prone to leaking, while any of the run upstream of the fan will be under negative pressure. You want any potential leak sucking air, not blowing.

Since the booster fan runs even when the machine fans are off, it helps keep the stink down. Speaking of stink, CA glue bothers my olfactory, so when I glue something up - I put it inside the glowforge so the fume is evacuated. :sunglasses:

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Hooray for multitaskers. Glowforge as a fume hood!

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I use a 100 cfm inline booster fan ($20 on amazon) with two 90 degree-ish bends with rigid vent pipe. Same as others here, it gets plugged in and run the entire time I’m projecting. There is always gonna be some smell, since the cut items themselves stink! Although, it isn’t super sucky, it is sucky enough, since I only really get a smell when my :glowforge: is opened. May consider more cfm, but the setup I currently have works great.

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I use this one, and it’s quite effective:
https://www.amazon.com/gp/product/B01M7S46YZ

I picked up 25’ of this hose at the same time, and it’s much more durable than the one provided.
https://www.amazon.com/gp/product/B075JB7VG2

Finally, I also picked up one of these filters. It doesn’t eliminate the smell completely and I still vent outdoors most of the time, but if I need a quick cut on most wood it works great.
https://www.amazon.com/gp/product/B01CJ5D4AG

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