• Move to lemm.ee@lemmy.world
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    1 year ago

    This isn’t just mildly interesting. We should be considering methods of air cooling that do not use any carbon in order to avoid aircon usage becoming a contributor to the climate problem as things get hotter and hotter.

    • MetaCubed@lemmy.world
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      1 year ago

      I agree with you that we should be exploring alternatives, but aircon is extremely energy efficient for how much thermal energy it moves (reaching 400% efficiency in some cases) . The problem isn’t aircon itself, but what is being used to power it (coal/natural gas power plants)

      In fact the technology behind aircon can be expanded into a heat pump to both heat and cool, being more efficient than electro-resistive or gas heating. There’s even water heaters that will actually cool the area they’re in and use the heat they gather from the space to heat the water.

      Technology Connections has a great series of videos that go in depth on both heat pumps and aircon.

      • spongebue@lemmy.world
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        1 year ago

        Yeah, “air conditioning powered by solar/wind/hydro” can feel like it’s one big Rube Goldberg machine to make air cool, but the reality is that it comes together to make something that can scale really easily. I can’t imagine coming up with a design like what’s in OP for an apartment complex or condo building.

        Source: just made it up, but also a Technology Connections fan. All that’s to say, feel free to correct me with a little data

      • grue@lemmy.world
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        1 year ago

        400% efficiency is good, but it’s not better than the ∞% efficiency you get from something that doesn’t require fuel input to begin with. (I’m pretty sure the Technology Connections guy would agree on that point.)

        If nothing else, think of it this way: even if you still want to use air conditioning to make sure you get all the way down to comfortable room temperature or whatever your target is (which a Qanat, although able to achieve a >15°C ΔT, might or might not be able to do reliably), it’ll still give you a big head start and greatly reduce the amount of energy needed. It’s a lot like using a ground-source heat pump instead of an air-source one. What’s not to like‽

        • MetaCubed@lemmy.world
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          1 year ago

          Sorry my point wasn’t that we shouldn’t explore other options to use instead of/in tandem with A/C. I was entirely pointing out that the use of an AC/heatpump is by itself, in absence of the context of what is used to power it, a non issue as its one of the most efficient electric heating/cooling technologies we have.

          Wind catchers could be, and likely are a great technology to adapt for wider use, though I can’t speak to that, I’m not an HVAC engineer.

    • Lazz45@sh.itjust.works
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      1 year ago

      This would be a great idea if you want everyone in that building to file humidity complaints every single day. Air conditioners work by using mechanical work (compressor) to exploit evaporation in order to pull heat from one location to another and exhaust it away, in turn cooling the first location (this could be air, water, etc.)

      This system works by using ground temp water as a heatsink to suck heat out of the air passing over it. When it does this, it humidifies the air. In the desert…who cares? In an office building…who cares? Every single worker who is stuck there all day

      If you’re saying we need better systems than the AC unit you grew up with, fear not! Many office buildings have been moving away from it (same with other large venues) they use a chilled water system. They use the best of both these systems to get WAY more performance out of way less wattage. You only need a fraction of the cooling power with a chilled water system because the water can absorb much more heat per unit mass than air and can be sized to never run during the day, but only at night when the grid is least in use

      • Move to lemm.ee@lemmy.world
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        1 year ago

        AC unit you grew up with

        Lmao grew up with? Most of us have never used AC at all in europe. Here in the UK no homes have AC. The issue is that people are installing it now because of climate change and the result is massively higher energy use.

        • Lazz45@sh.itjust.works
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          1 year ago

          Not necessarily in your house. I’m talking about the design of the units from when you were a child (Many public buildings in the EU have AC regardless of houses not having it). AC was invented in 1901, and has come a very long way since then, and we have begun combining it with old principles to extract the best of both solutions

          Combining modern refrigeration/cooling techniques with well designed passive systems that exploit material properties (Heat capacities, transfer coefficients, etc.) to their advantage is the future of HVAC. It started with CFCs and knowing we could exploit their boiling point with mechanical force to chill air beyond the outside air temperature. Who knows where science and engineering may take us next!