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.
this post was submitted on 24 Jul 2023
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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.
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
They actively use this design in large buildings (with a modern twist). Its known as a chilled water system: https://hvactrainingshop.com/how-a-chilled-water-system-works/
Or you have ones that do not run at all during the day, and only chill/freeze the water at night on excess power/cheap power: https://www.buildinggreen.com/news-article/making-ice-night-cool-buildings
The second system I linked would then let the ice slow melt over the day as its way of actively chilling air passing through its exchanger.
These systems work by chilling water instead of air, which has a much higher heat capacity. Meaning, it can accept much more thermal energy per unit mass before raising its temperature by 1 kelvin. You are able to build a single, very well designed, and efficient refridgeration unit that can provide HVAC services to up to multiple high rise buildings. This reduces waste and reduces the usage of coolant/refridgerant.
This system can be reversed in the winter (heating the water instead of chilling) with geothermal heat, solar heat, or if no "green" options are readily available, natural gas direct fire heat can be extremely efficient compared to electric coil
One of our data centers uses a building with a man made "lake" in it. They blow the air across the water and use that air to cool the building and its systems. Seems to work fine.
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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‽
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.
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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
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.
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Ancient Iran had swamp coolers* to be more accurate here.
This works in the desert, but you can't replicate it in a humid climate like you can with AC.
I came across this exact thing when researching air conditioning. And since I was interested in a good soltution for the tropics these Yak'chals as they're called are basically useless. The tropics regularly have dew points of 26°C and above.
It can kinda work with an elaborate setup and a (liquid) desiccant cycle but in the end you still want the evaporation cooling outside, especially in the tropics where you have legionella practically instantly if you humidify anything indoors. And that will tank the efficiency. But it kinda works. The more humid the weather the hotter the regeneration of the desiccant has to be to work.
Video 1 Experimental setup indoors to show the concept
Video 2 Solar setup outside
The very term Air Conditioning refers to a technical system, that is deliberately influencing aka conditioning the properties of the air.
So yes, this is an ancient AC system.
Cool, but that's not what we mean when we say AC. The meanings of words change over time and AC is used almost exclusively to refer to a specific type of device so unambiguous that I don't usually have to explain which exact type of device I mean.
Otherwise literally just putting up a fan next to your window is technically AC. The term AC will lose all meaning.
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Not quite an air conditioner, but it seems modernizing it could be a great idea for new constructions to save on power. Maybe as a supplement to Air Conditioners.
passive house design
Not quite an air conditioner, but it seems modernizing it could be a great idea for new constructions to save on power. Maybe as a supplement to Air Conditioners.
It's called "radiant floor cooling/heating" and this has existed for a while.
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Cool, but a quick search shows that these towers can cool a place by around 10C. So, in the scorching 50C desert, the interior would be above 35C, which is still fucking hot.
Edit: I get it, this idea is awesome and ancient. I just don’t like the “this is the future, AC is bad” tone of the article that, masterfully, decided to omit how much it can cool down a place.
Wikipedia claims "greater than 15 °C." Besides, even if you supplement it with air conditioning, that's 15 °C less ΔT worth of electricity you have to pay for.
You can literally go there and witness these for yourself. It works. People live in Yazd right now in these old buildings. Newer constructions have air conditioning because building huge thermal mass retaining walls out of mud bricks is expensive. They keep ice all winter in buildings there from a thousand years ago cooled like this.
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I think that the Eastgate Mall in Zimbabwe makes usage of a similar principle, but their inspiration came from Termite Mounds https://www.youtube.com/watch?v=qP8DSdfoiZw
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I was told that the houses in trinidad, Cuba have a similar cooling effect. Also the round white houses in tunesia have a cooling effect. Any tunesian or Cubans here?
Wow, I thought quanat was a made-up word from dune.
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