Negative Pressure Indicator- Check this out

[coldcanna]

So I'm in the building trades, we are currently working in a chemistry lab for a large university and for safety purposes all of the rooms are set up on neg-air. I noticed this little rig above the door outside, its a super simple idea.... If neg air is functioning the ball is sucked into the room, if neg air has been compromised or you open the door, the ball roles out to the front of the unit and lets you know.



They sell them on airflowdirection.com for $385, a bit steep for many I would imagine but I think this item may have its place. Especially for those of us working in congested urban areas or apartments, being aware of any possible leaks of smell before they cause neighbors to start searching for that skunk aroma. Anyhow, hope someone finds this useful as I thought it was pretty interesting, could spark some DIY projects

 

[DapperDon]

Now for our industrious community to try and reverse engineer this puppy for a diy on the cheap. Good find.

 

[jayjayfrank]

that thing can probably be 3D printed

 

[coldcanna]

I was told we'd be installing one in the new space we're building, I'm hoping I can get my hands on it and bring some details back to the boards here. Its pretty much a ping pong ball, and the plastic tube is sloped OUT of the room so in the absence of pressure it roles out. Not sure how much vacuum in the room is required to pull it inwards so I guess thats the next bit of info to figure out

 

[Gry]

Very nice, love the ingenuity.

 

[flyer81]

I hung a curtain in the doorway into my room. With an I/O fan controller I can manipulate whether that curtain billows out or is sucked back into the room. I have it set so that it is pulling air into the room. Not so much that it rapidly sucks all the co2 out but enough to keep the air pressure from pushing smells out through the cracks.