This is an excerpt from Dr. Joe Lstiburek's Building Science Fundamentals class, a 16-hour class taught remotely over two weeks. This segment is about ductwork: leaky ducts, sealed ducts, and apparently, human ducts.
Transcript:
Think about me. Let's pretend that I'm a duct and I'm connected to a rooftop exhaust fan. So I suck. Joe sucks. I'm not particularly well put together, so I leak.
So I've got a rooftop exhaust fan with a duct attached to it that leaks. And let's pretend that I'm built into this wall. So if I've got a leaking duct operating under negative pressure that's built in the wall, I'm going to pull air into me, right? And I'm going to pull the air out of what? Out of the interstitial space. Which means that that wall cavity is going to go negative. And it will go 10 or 20 feet because the wall is not compartmentalized, right?