Why is it in Hollywood movies every time there is a vent or AC unit someone has fixed little ribbons on it? Is that a thing americans do? Why? The vent in this movie is close to the floor in the toilets of a train. This implies someone got on all fours ON THE FLOOR OF A TRAIN’S BATHROOM to stick those ribbons there for a reason i can’t even begin to comprehend.
Maybe american viewers will be so kind as to tell us in what kind of context they do see ribbons in real life and even post a few pictures?
It’s to show the viewer when the vent is on or off. Typically only when the fact of it being on or off is important.
Ribbons (or visual indicators in general) wouldn’t have been stuck on there by a member of the public. It would have been placed there by technicians or maintenance guys to help with their tasks. Not common at home for obvious reasons, but not uncommon in commercial / public spaces.
Hollywood took an existing practice and made it ubiquitous because it was a convenient visual shortcut.
The practice is only used when the vents are hard to reach, Hollywood puts them eveyrwhere, like OP said behind a toilet, where the technician can easily verify by hand or with the actual tool to measure airflow so they have an actual metric to see if it’s deteriorating.
Its a Hollywood trope.
It’s not a thing in real life either…
HVAC techs will use the anemometer that’s part of their standard kit, they aren’t going to tie a fire hazard that collects dust to a duct….
If you see them left behind, that’s because the company was too cheap to cleanup their garbage, they would ONLY be used while the techs were actively diagnosing a persistent issue, but it should be removed when done.
Why do people perpetuate obvious fake Hollywood stuff? Do you think code will allow you to permanently affix something flammable to a duct that would be heated and can catch it on fire……?
I thought it was because cheap motels built in the 50s, would do that to show you how cold the ac blows
The answer in movies is the same as IRL: it’s to visually indicate that air is moving through the vent. In a movie this can be hard to tell the audience without a possibly annoying sound. In real life you might see this on vents that are difficult to access, probably so an HVAC technician can tell if the vent is working.