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!

  • schmieroslav@discuss.tchncs.de
    1081·
    1 year ago

    I think that the evaporation in theory is able to cool the room, the heat energy is transferred into launching a bunch of water molecules airborne so to speak. Hanging some wet towels around would also do that.

    However, the performance of such small devices is probably not sufficient to significantly cool a room, and it has a lot of drawbacks (filter gets mouldy easily, …)

    Here’s an excellent video about these swamp coolers: https://youtu.be/2horH-IeurA (he has many videos on heat pumps and stuff)

    • eth0p@iusearchlinux.fyi
      491·
      1 year ago

      Aw. I was going to post the link to his video, but you beat me to it.

      But yeah, Technology Connections makes some excellent and informative videos. To anyone else who sees this: If heat pumps, refrigeration, or climate control technology aren’t your cup of tea, he also covers older technology based around electromechanical designs (as in, pre-dating microcontrollers and programmable logic) and analog media recording devices.

      • JimmyMcGill@lemmy.world
        34·
        1 year ago

        I mean even if they aren’t your thing you should check out his videos.

        I remember watching a 20 or so min video on an antique toaster and since then I’m also pissed at the inferior toasters of today.

        His videos are gold.

        • FlapKap
          5·
          1 year ago

          Can someone please explain why toasters aren’t made like that anymore?? I would happily forgo the led and the obnoxious ding they make to have them make the toast perfectly every time

        • Rhaedas@kbin.social
          3·
          1 year ago

          That may have been my intro video to him. Can’t go wrong with any topic, no matter how trivial it may sound. You will come back afterwards saying, wow, never knew that.

    • givesomefucks@lemmy.world
      10·
      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

        • Chocrates@lemmy.worldEnglish
          3·
          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.

      • moeggz@lemmy.world
        2·
        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.