4" Vent option in a basement window?

I am planning to up my production of my Glowforge here in October. I have been selling things through my web site, but my stock is depleted, and people are starting to Christmas shop. There is also the potential for craft shows but I haven’t signed up for any yet.

Anyway, my Air Filter has been working great for light use, and allows me to put my Glowforge near my workshop. Unfortunately, it it fills up too quickly for what I am going to need to do over the next 4-6 weeks. Simply put, I need to go back to venting. I also need to cut a lot of MDF for a few of the items I sell, and that isn’t recommended on the air filter because it is so dusty.

I have a 15x20" tilted basement window that I was venting out of originally but it was a very hacky solution. Each time I want to use the Glowforge I have to open the window. and connect a hose to it. The hose runs to a plastic window well cover that has a 4" vent in it (that automatically closes when not in use). The downside to this solution is that I have to open and close the window up, and the window well doesn’t keep the smell out anywhere near what the filter does.

So my thinking is to have some thick acrylic cut with a a 4" vent. Then I would put some a dryer insert in it so I could connect my Glowforge hose to it. My wife does not want me to use glass block, but there are existing options available for this. So far, I can’t find anyone locally that is able to do acrylic (still looking around). The window I have has “arms” that hold a window casing to it, but it’s definitely going to be a custom job. The thickness of the acrylic window, the casing, etc. would have to be figured out for it to fit the same way. I don’t trust myself to do it, because of potential leaking. My goal is also to be able to put the original window back in if needed.

I was wondering if anyone here has suggestions or recommendations. I also thought about cutting a hole in the siding, but that option isn’t ideal for our situation, mainly because it’s an extra hole that is only needed for a laser cutter.

Edit: here is a past thread that shows the venting set up, along with the window that I’d like to change. My venting setup, and quest to remove odor and noise

Search for “basement window” and there are other discussions. This has been pretty well vetted.


A lot of ideas there, but nothing specifically around what I am asking. I always search before I post, Did you read my post?

Of course I did.

It said [paraphrasing] “I have a very specific window issue, and am looking for ideas”. Nobody’s going to have a drop-in solution for you, the best you’re going to get is similar situations. Ergo, search and read other threads for inspiration, this sort of thing has been discussed.

If you’ve already done this, I’m not sure what else to tell you. You describe your situation and your potential solution pretty well, there’s no great way for any of us to know it it’ll work. You didn’t provide pics or anything, we’d all be shooting blind if we went down this path any further at this point.

Did I read it. smh.

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Oh I will say that if you do go with your acrylic idea, you can probably get it cut to size at like professional plastics, or even take it home and tablesaw it. It’s just a rectangle, no big deal. As for the vent hole, if you have a pro, you can passthrough that thing to cut the 4". If you have a basic… there are ways to defeat the interlock (magnets, yo), and you can stick the end of your 15x20 into the basic to cut the vent (maybe not exactly centered, the GF isnt quite that deep I don’t think. Maybe?)

Centering the hole probably isn’t the biggest concern anyway.

Good luck!

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Pictures of your window/setup would be helpful.

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Here is my venting set up.

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One idea that I am exploring is swapping out the tilted window for a side by side sliding window, and making a manual wood insert with a 4" vent.


Thanks, I’m really just looking for ideas to bounce around off people on this forum, which I’ve found helpful in the past (and have also shared ideas). I know that there is always the risk of the same questions being asked repeatedly and that can be annoying. I have not been as regular on this forum in a while, and maybe things have changed since I last posted, but there is still value to folks being able to hear from others,

Well, the idea seems pretty sound. If you want to get fancy, you can put a magnetic quick release on the acrylic insert, and make a corresponding “plug” so you can close it off when you’re not using it. (or use a blast gate).

Ventilation ideas abound on here, but they really all boil down to a few basic concepts: weird window compensation, external fan recommendations, and how to prevent backflow (aka quick releases, louvers, and blast gates).

Nobody knows your setup better than you do, sounds like you’re onto something.


Is that unit double pane? If the glass is not single pane set in putty, double pane insulated units are generally set in the frame with a double sticky tape.
When they are replaced the glazier will use a razor knife to cut around the glass and the unit pops out. The setting tape is readily available for when you want to reset the glass.

After cleaning the seat of residual setting tape, you could set an acrylic window in there with your access hole cut in it using the same type of setting tape.

As for the odor you’re experiencing, those booster fan housings need sealing because they are pressurized. I used caulk.


Can you remove the glass from the window? (Just the glass, they are usually attached with a putty that is pretty easy to scrape out.)

I’d take the glass out, cut a sheet of acrylic to fit (doesn’t have to be thick) cut a hole in that for the port and just vent straight through the window. (Lose the window well cover.)

Something like this works great, and the acrylic works just as well as glass for keeping things out.

A few screws and silicone caulk to seal the ports to the acrylic. When you want to go back to using the glass, you can just remove the acrylic pane and put the glass back in.



Here’s my solution to using a very similar window:

Thanks Jules! I was wondering the same thing originally. I am not entirely sure how the casing is holding the window in. This might be a good option if I can remove the window, and find the exact same thickness of acrylic.

Thanks, that does seem to be very similar to what I’m trying to do and what Jules also suggested. How difficult was it to remove the glass from the window pane? I am not even sure how to do that.

It was very easy to remove the glass. On the outside of the window, with it open, you should be able to see the screws that hold the frame together; the screws are not reachable when the window is closed, to prevent bad actors from opening your windows. Unscrew the frame, and the window insert should come right out, with some careful convincing, to not rip the gasket/sealant.


Thanks, I didn’t even look at the outside of the window. I will check it tonight when I get home. This might be my best option…

Thanks for the info. It seems like I definitely need to explore the option of replacing the glass with acrylic before I do something more significant. Thanks for the suggestion on caulk also. I was using tape but caulk seems better.

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It worked better for me, I have an extended exhaust run, and after I sealed the fan housing and every joint and seam in the rigid vent pipe I have zero odor during operations. :sunglasses:

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I am assuming that you can’t cut a hole in the house? I cut through the basement wall. It was actually an incredibly quick install and has survived 2 winters so far without an issue. It’s pretty easy to do (you just need a 4" hole saw).