shower curtains: why do they blow in and up?

[Darren Dirt]

Why does the shower curtain blow in and up, instead of out and down?





"Straight Dope"

http://www.straightdope.com/classics/a2_104.html



"revisted, i.e. part 2"

http://www.straightdope.com/columns/010810.html



I was seriously wondering this on the weekend, just found the above by a complete fluke.



...It's funny cuz its counterintuitive...

[Lazybones]

Not that computer models are wrong often but I think that the answer is overly complex and possibly only one of the causes.



My theory?



Hot air rises and escapes via the big gap above the show rod. Cold air enters the bathroom from under the door and is sucked into she shower at the bottom of the curtain to replace the escaping hot air.



Here is my question, has the curtain ever attacked you while taking a cold shower

[Darren Dirt]

Not that computer models are wrong often but I think that the answer is overly complex and possibly only one of the causes.



My theory?



Hot air rises and escapes via the big gap above the show rod. Cold air enters the bathroom from under the door and is sucked into she shower at the bottom of the curtain to replace the escaping hot air.



Here is my question, has the curtain ever attacked you while taking a cold shower

I thought that at first too, but one of the 2 "straight dope" columns mentioned that he had (multiple times) tried it with ice cold water as well -- same effect. Bottom line: it's all about air pressure, the OCD Dr. Schmidt mentioned above may have used some computer programming trickery to prove it, but the theory behind it was probably a lot simpler and easier to understand than the numbers themselves.



The real question is, will the shower-curtain effect be more or less intense, if you have a window open during your shower?  :?: