147
submitted 1 year ago* (last edited 1 year ago) by PlutoniumAcid@lemmy.world to c/asklemmy@lemmy.world

Prove me wrong, please?

edit: thanks for all the great comments, this is really helpful. My main take-away is that it does work, but requires dry air. In humid conditions it doesn't really do anything.

Spouse bought this thing that claims to cool the air by blowing across some moist pads. It's about as large as a toaster, and it has a small water tank on the side. The water drips onto the bottom of the device, where it is soaked up by a sort of filter. A fan blows air through the filter.

  1. Spouse insists that the AIR gets cooled by evaporation.
  2. I say the FILTER gets cooled by evaporation.
  3. Spouse says the cooled filter then cools the air, so it works.
  4. I say the evaporation pulls heat (and water) from the filter, so the output is actually air that is both warmer and wetter than the input air. That's not A/C, that's a sauna. (Let's ignore the microscopic amount of heat generated by the cheap Chinese fan.)

By my reckoning, the only way to cool a ROOM is to transport the heat outside. This does not do that.

We can cool OURSELVES by letting a regular fan blow on us = WE are the moist filter, and the evaporation of our sweat cools us. One could argue that the slightly more humid air from this device has a better heat transfer capacity than drier air, but still, it is easier to sweat away heat in dry air than in humid air.

Am I crazy? I welcome your judgment!

you are viewing a single comment's thread
view the rest of the comments
[-] givesomefucks@lemmy.world 10 points 1 year ago

, and it has a lot of drawbacks (filter gets mouldy easily, …)

The more immediate drawback is after running it for a little bit, you'll lose the ability to sweat.

Well, you'll still sweat, it just won't evaporate due to high humidity.

It's at best a very short term solution before it starts making it worse

[-] moeggz@lemmy.world 2 points 1 year ago

Unless you are in a dry climate. Our house is cooled almost entirely off of a swamp cooler (small window unit for the bedroom) and the humidity is never noticeably high.

Gotta live in a desert for that. If not yeah swamp coolers are very limited.

Plus if you have AC then the AC has to dehumidify the air first before it can cool it.

[-] Chocrates@lemmy.world 3 points 1 year ago

That isn't how AC's work. They work by using the fact that a phase change between a liquid and a gas is endothermic. It turns a refrigerant into a gas and that sucks heat from the air in your house and then pumps that gas outside to cool off with your compressor, moving heat outside. (Someone correct me please if I got details wrong). The act of pulling that heat from the air into the phase change cools down air and water condenses out of the air, dehumidifying it. Fun fact AC's weren't designed for our comfort, some facrory needed less humid air for their product, us lazy workers cooling down a little is a side effect.

https://en.wikipedia.org/wiki/Enthalpy_of_vaporization#:~:text=used%20among%20others.-,Enthalpy%20of%20condensation,-%5Bedit%5D

The cooler air converts the water from a gas to a liquid which generates heat. The more water in the air the more heat gets generated. You don't really get as cool of air until the air has been dehumidified.

this post was submitted on 18 Jul 2023
147 points (91.1% liked)

Ask Lemmy

26831 readers
277 users here now

A Fediverse community for open-ended, thought provoking questions

Please don't post about US Politics. If you need to do this, try !politicaldiscussion@lemmy.world


Rules: (interactive)


1) Be nice and; have funDoxxing, trolling, sealioning, racism, and toxicity are not welcomed in AskLemmy. Remember what your mother said: if you can't say something nice, don't say anything at all. In addition, the site-wide Lemmy.world terms of service also apply here. Please familiarize yourself with them


2) All posts must end with a '?'This is sort of like Jeopardy. Please phrase all post titles in the form of a proper question ending with ?


3) No spamPlease do not flood the community with nonsense. Actual suspected spammers will be banned on site. No astroturfing.


4) NSFW is okay, within reasonJust remember to tag posts with either a content warning or a [NSFW] tag. Overtly sexual posts are not allowed, please direct them to either !asklemmyafterdark@lemmy.world or !asklemmynsfw@lemmynsfw.com. NSFW comments should be restricted to posts tagged [NSFW].


5) This is not a support community.
It is not a place for 'how do I?', type questions. If you have any questions regarding the site itself or would like to report a community, please direct them to Lemmy.world Support or email info@lemmy.world. For other questions check our partnered communities list, or use the search function.


Reminder: The terms of service apply here too.

Partnered Communities:

Tech Support

No Stupid Questions

You Should Know

Reddit

Jokes

Ask Ouija


Logo design credit goes to: tubbadu


founded 1 year ago
MODERATORS