I live in a high-rise apartment and just discovered that one of my walls has this port for a portable AC exhaust.
I double checked with my building and they did confirm it can be used for a portable AC unit. Any reason why I can’t use it for Glowforge exhaust?
If it’s just for air and condensation from an AC unit, could I clog it? Does the glowforge vent any particles that could clog the vent?
Unknown how much. My pipe is quite sooted inside. Wonder what happens if someone sees smoke coming from an AC vent?
I would want to check what else it connects to. If it’s an open plenum that your neighbors also have vents like that into, then would your laser fumes go into their apartments?
Odd that the difuser cap is inside your apartment. 
If the vent only services your apartment, it might work, but if there are any other vents that tie in to a common duct, it could be quite hazardous. Over time, particulates can build up, which might require occasional duct cleaning (and lead to a telltale stain near the external opening).
If you know your neighbors and if they have the same vent in their apt. (that’s not in use). The quick 'Gyver test would be an aerosol-based air fresher and a hair dryer set to high with no heat. And ask if they can smell anything. If so. Then it can’t be used. As stated by @dwardio the fact that the defuser is inside the apt. makes it extra sketchy. I’d start working on a plan B.
Nah, get a smoke machine and pump it through it. If the fire department shows up, you know it vents to someone else’s apartment.
This is why I love this forum…a bit twisted humor goes a long way 
I have noted some small particulate on my screen (using magvent to vent through the screen). It has been nothing that a few seconds with rubbing alcohol and a toothbrush didn’t completely clear. I suspect long enough usage, you could theoretically clog a vent, but that would take a VERY long time. Compressed air would probably clear 95%+ of that.
If anything you send through there goes into someone elses apartment, then they made it wrong.
I think you’d be doing them a service in testing their venting installation 
. It would take an awful long time to clog it - as in longer then you’ll probably be living there.
this is undoubtedly true, but if you’ve seen many homes/apartments/commercial buildings, you know they routinely make things like this wrong.
aye, and as soon as someone starts getting smoke billowing into their apartment im sure theyll have to fix it pretty quick. thats not up to code (if its in the US)
I stayed at a flea-bag hotel one time when I was younger. I asked for a room with a kitchen. Decided to cook up some hamburgers for dinner and turned on the vent over the stove. Next thing I knew, everyone on that floor was out in the hallway complaining about an awful smell in their rooms.
Awful smelling burgers !?
Were you cooking rat meat or something ?
I have yet to smell an awful hamburger…
You’d be surprised how bad cooking meat can seem when you don’t know what it is.
Portable AC unit would pump out hot air - which other apartments wouldn’t want coming in in the summer. However, the fact that there appears to be a “cap” to close it if not hooked up would make me think it may very well be “networked” with the other vents. (How many stacks do you see on the roof?)
