• DarthBueller@lemmy.world
        link
        fedilink
        English
        arrow-up
        9
        ·
        1 year ago

        Amazing - I had no idea that anyone was making ice in the desert in BCE times. The wikipedia article seems to indicate that they did a lot of storing of ice in the Yakhchal structures - but it is confusing as to how they made it. It seems like they either gathered the ice from the mountains, or made it in outdoor shaded “ice pools” that were situated next to the Yakhchal. Surely the ice required winter desert temps to form? Otherwise how would the thermal mass of the ground ever get cool enough to allow ice to form, even with the magic of physics? The permanent shading helps, but year round-ice making surely wasn’t a thing, was it?

    • MeanEYE@lemmy.world
      link
      fedilink
      English
      arrow-up
      22
      arrow-down
      2
      ·
      1 year ago

      It’s called evaporative cooling and it’s quite potent since water takes enormous amounts of energy when changing states. It takes around 5x the energy to convert 100°C water into 100°C vapor than it takes to increase temperature of said water from 0 to 100°. This energy has to be taken from somewhere and that is from the environment, dropping the temperature as a result. Problem with these is that the humidity of the air increases. Not much of a problem in desert, quite a bit problem in other places.

      Here’s a great video explaining science behind evaporative coolers and how it can be modernized. https://www.youtube.com/watch?v=R_g4nT4a28U

      Just wind tunnels without water, I agree with you.

    • JohnDClay@sh.itjust.works
      link
      fedilink
      English
      arrow-up
      10
      ·
      edit-2
      1 year ago

      Wind powered swamp cooler. Basically a humidifier, but it does lower the temperature. I’ve heard people call swamp coolers air conditioning, so I don’t think it’s wrong.

      • boonhet@lemm.ee
        link
        fedilink
        English
        arrow-up
        1
        arrow-down
        2
        ·
        edit-2
        1 year ago

        No, calling swamp coolers air conditioning is definitely wrong.

        If it’s 100% humidity in your room, the swamp cooler is going to do absolutely nothing, but AC will cool it down and can even dehumidify a bit if you run it enough.

        Swamp coolers are awesome, but they only work in dry climates unfortunately.

    • jerry@lemmy.world
      link
      fedilink
      English
      arrow-up
      8
      arrow-down
      1
      ·
      1 year ago

      No, it’s a swamp cooler, which is still used today in drier climates. This is a desert, so yes the air is not humid, and yes the water is cool because it’s underground. Stop being so pedantic.

    • hamid@lemmy.world
      link
      fedilink
      English
      arrow-up
      5
      arrow-down
      1
      ·
      edit-2
      1 year ago

      LOL Your comment makes it seem like you don’t think that it couldn’t possibly work, except that these things are still there and you can go visit them right now and feel how cool it is inside the buildings.

    • boonhet@lemm.ee
      link
      fedilink
      English
      arrow-up
      3
      arrow-down
      1
      ·
      1 year ago

      The water doesn’t actually have to be all that cool for swamp coolers, because it’s the evaporation that cools the environment and warm water actually evaporates quicker.