Post AxmqHSrFQ5vaBYvLsW by JoscelynTransient@chaosfem.tw
(DIR) More posts by JoscelynTransient@chaosfem.tw
(DIR) Post #AxmqHSrFQ5vaBYvLsW by JoscelynTransient@chaosfem.tw
2025-09-02T03:24:44Z
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Question: are any air ducts in actual buildings big enough for a person to fit through?It’s such a staple of movies that we just accept…but like, I’ve never seen one bigger than maybe I can fit my arm into. Makes me wonder, is there any kind of building where that’s actually a thing?
(DIR) Post #AxmqHU3KydBztLaWMS by azonenberg@ioc.exchange
2025-09-02T03:47:48Z
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@JoscelynTransient Ones that go to wall vents, probably not.Central routes to a roof mounted air handler? Sure. Just look up next time you're in a Walmart.Whether they're hung well enough to climb through without collapsing is another question (and of course you'd make such a racket crawling on the sheet metal every baddie in the building will know exactly where you are).
(DIR) Post #AxmqHUvvherScf87SC by azonenberg@ioc.exchange
2025-09-02T03:49:52Z
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@JoscelynTransient but like this one https://hvacdirect.com/48-inch-diameter-20-gauge-spiral-pipe-sp-48-20ga.html is 48 inches or 1.2 meters in diameter.A young kid could stand upright in it and an adult could easily fit if they bent over or crouched (you wouldn't even have to crawl)
(DIR) Post #AxmqHVvG1duxgrp62q by JoscelynTransient@chaosfem.tw
2025-09-02T03:54:51Z
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@azonenberg that makes a lot of sense. I was thinking like at the juncture of big AC systems for a whole building, it could make sense. And now that you mention it, definitely seen those big ones in big box stores and supermarkets. But yeah, almost never for a wall vent.And yeah, makes sense too that they are mounted to hold the vent and air, not the body weight of a person 😅
(DIR) Post #AxmqHWuEMwgsjyLn5E by azonenberg@ioc.exchange
2025-09-02T03:57:32Z
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@JoscelynTransient I mean, sheet metal ducts of that size are not light. But add another 100kg single-point load and I could see some of the threaded rods ripping out depending on how they're mounted.Running them to a wall vent would be stupid and is mostly a thing of movies.
(DIR) Post #AxmqHXoazNmFYminwG by iwein@mas.to
2025-09-02T04:44:56Z
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@azonenberg I've climbed on those in an old tin factory as a kid (don't tell my mom please). They were mounted with 8mm steel bolts and felt quite solid. Definitely less dodgy than climbing a pvc mounted rain pipe.I'd be scared to death going inside one though. Not big enough to turn, no light, snags, rats, spiders, lots of dust... 😱Maybe it is not impossible, but not like the movies, I think.@JoscelynTransient
(DIR) Post #AxmqHYPokzYFQE8WxM by JoscelynTransient@chaosfem.tw
2025-09-02T04:48:46Z
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@iwein @azonenberg that’s another thing I’m wondering: was it more common in older buildings once upon a time? Interesting to hear they were rather solid after all (though admittedly for kid size).And yeah, no way those things are shiny and clean like the movies on the inside. I’ve replaced air conditioner filters and those things get nasty
(DIR) Post #AxmqHZ5eFT0nVxhw9o by brettm@swarm.coiloptic.org
2025-09-02T06:08:05Z
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@JoscelynTransient@chaosfem.tw yes eg in shopping malls, universities, stadiums (any place with lots of ppl) the vents can get prety huge. And insome places they don'tbranch off to smaller vents, the ventholes are right there in the main pipelines.Sidenote: the maths of designing aircon vent systems is quite complicated. I don'tunderstand it that's for sure. World leader Mitsubishi aircon pays some Julia programming language group lots of cash to improve the constrained differential equations (or whatever its called) support in Julia sothey can design building aircon ducts better.
(DIR) Post #AxmqHa00ru6AKm4x0q by JoscelynTransient@chaosfem.tw
2025-09-02T03:33:29Z
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Seems there are some…does anyone know when and how they are used?
(DIR) Post #AxmqHhBy7qoydsj67U by JoscelynTransient@chaosfem.tw
2025-09-02T03:35:15Z
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I feel like this is one of those things where there’s some amazing person on the fedi who has a hyperfocus on air ducts and vents and can infodump more than I realized I wanted to know about them