# More polite to leave bathroom fan on or off?

**URL:** <https://boards.straightdope.com/t/more-polite-to-leave-bathroom-fan-on-or-off/1011317>\
**Category:** In My Humble Opinion\
**Created:** [December 7, 2024, 7:33pm UTC](https://boards.straightdope.com/t/more-polite-to-leave-bathroom-fan-on-or-off/1011317 "2024-12-07T19:33:51Z")\
**Posts on this page:** 1\
**Showing post:** 33

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**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\
**Post date:** [December 10, 2024, 10:32pm UTC](https://boards.straightdope.com/t/more-polite-to-leave-bathroom-fan-on-or-off/1011317/33 "2024-12-10T22:32:23Z")

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Houses are not and should not be literally hermetically sealed. In another recent thread, I learned about how many air changes per hour they’re supposed to have.

> [@Why does my apartment require so much water from my humidifier to increase the humidity](https://boards.straightdope.com/t/why-does-my-apartment-require-so-much-water-from-my-humidifier-to-increase-the-humidity/1011329/8):
>
> That’s incredibly aspirational though. The Passive House standard, the toughest building standard in the world can be passed with 0.6 ACH. Modern building codes tend to mandate somewhere around 3ACH and older houses would often have 15 - 25 ACH.

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