| ▲ | leereeves 16 hours ago |
| That sounds like a lot, but a million cubic meters is only a cube 100 meters on each side. So it's on the order of the air in a football stadium. A 1200 CFM home air conditioning system moves roughly 20 million cubic meters per year. |
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| ▲ | myrmidon 16 hours ago | parent | next [-] |
| Sure. But thats still very much a lower bound, and it makes a bunch of idealizing assumptions that are hopelessly overoptimistic (assuming your intake gets the full 400ppm of CO2, and you manage to extract all of it in one go). Even from those numbers, you already get up to a football stadium of processed air per hour for every small town. For a big city, you need to process that football stadium worth of air every second. Building infrastructure of that magnitude is a major commitment, and if most nations can not be arsed to replace a small number of fossil power plants per country, I honestly don't see us building large air processing plants in every single town in a timely manner (that are extremely likely to be less profitable than replacing the power plants). |
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| ▲ | themaninthedark 13 hours ago | parent [-] | | What is the size of these process units? Can it be coupled with current air processes? Every house, office building and factory has air handling units. Factories and other industrial sites also use compressors. | | |
| ▲ | gus_massa 6 hours ago | parent | next [-] | | It converts CO2 and H2O into ethane and ethylene, oversimplifying the output is natural gas. What do you do with the natural gas? You can put it in pipes and send it to a central location, but you need pumps and the pipes are a nightmare. You can store it in a local tank but you need a pump again, and burn it but it release the CO2 again. Using a solar panel and a battery is easier and more efficient. (Do they need also some water pipes?) For a distributed production, solar panels are much better. Pipes and pumps may work in a centralized setup, but I'm still not convinced it's better that biodiesel or ethanol. Photosynthesis is very inefficient, so there is a lot of room for improvement. But plants are like self building robots and they store the output in grains that are easy to transport. | |
| ▲ | teamonkey 8 hours ago | parent | prev [-] | | Right now they’re a fantasy so they can be as large or small as your imagination permits. |
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| ▲ | alnwlsn 15 hours ago | parent | prev | next [-] |
| Earth's atmosphere is 5.15×10^18 kg and at atmospheric pressure density is 1.293 kg m−3. The whole thing would be more like 4 billion billion cubic meters. So a billion AC units could have the whole thing cleaned up in just 200 years. Which would suggest that maybe as much as 0.1% to 1% of earth's atmosphere has ever passed through an air conditioner. |
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| ▲ | zdragnar 6 hours ago | parent | next [-] | | I was doing to say that surely it's a larger percentage, especially including all the commercial and industrial AC units running non-stop. Then I remembered that my dad didn't have indoor plumbing in his house for most of his childhood, and that 200 years is a much longer time than my first gut instinct. | |
| ▲ | nancyminusone 14 hours ago | parent | prev | next [-] | | This just has me picturing a scene where global warming is solved not by cleaning it up, but by leaving tons of window air conditioners everywhere, troll physics style, "to cool down the outside" | | |
| ▲ | filoeleven 43 minutes ago | parent | next [-] | | > The Stanford team’s passive cooling system chills water by a few degrees with the help of radiative panels that absorb heat and beam it directly into outerspace. This requires minimal electricity and no water evaporation, saving both energy and water. The researchers want to use these fluid-cooling panels to cool off AC condensers. https://spectrum.ieee.org/efficient-airconditioning-by-beami... | |
| ▲ | the_sleaze_ 14 hours ago | parent | prev [-] | | Psh, that's not reasonable. Outer space is like really really cold. What we need is a huge heat pump in outer space that pumps the planets heat out into deep space. All we need is a space-elevator style tube and we're good to go! | | |
| ▲ | lukan 13 hours ago | parent [-] | | You would need GIANT radiators. Space is cold but there is also allmost no cold material to transfer heat. So even with a space elevator .. not so easy. |
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| ▲ | azinman2 13 hours ago | parent | prev [-] | | Makes me wonder if ACs should have built in scrubbers. If that was the norm everywhere, you’d have some mild effect going on at scale. | | |
| ▲ | myrmidon 13 hours ago | parent | next [-] | | It would not hurt, but this just makes no (economic) sense currently, and that's not gonna change any time soon. Right now we don't have any CO2 scrubbing process without significant maintenance or operating costs, so this would add significant cost to all those ACs. Furthermore, the effect is marginal: With emissions of >6 tons of CO2/year/human, you would have to scrub a lot of air (>10m³/min with cost-free 100% efficiency, which is a pipedream) to compensate (for a single human); running the ACs on full flow all the time might not even be worth it depending on how efficient the scrubbing is and how clean the source of electricity. You might say scrubbing clean 10m³/min of air for every human sounds kinda feasible, but just compare the realistic cost of such a setup to the options that are currently implemented, and how much popular resistance/feet dragging they already meet (renewables, nuclear power, electrification, CO2 taxation). As a general benchmark, I would suggest that before the scrubbing technology in question has not managed to be installed at most major stationary sources of CO2 (coal/gas power plants, etc), it is not even worth discussing it for distributed air scrubbing. | | |
| ▲ | azinman2 13 hours ago | parent [-] | | You have to start somewhere. Even a not great solution can set the president, with goals to gradually increase the efficiency. Mandates can do a lot — just look at the catalytic converter. Put it on all HVAC systems and _something_ will happen even if a small effect given the HVAC itself is contributing way more CO2. We need all across the board solutions, and if you start requiring small scrubbers to function that can start to provide scale effects that can translate for bigger systems. | | |
| ▲ | gus_massa 2 hours ago | parent [-] | | Catalytic converters have to convert a tiny part of the output, and they convert them into more stable forms. The problem with CO2 is that it's the most stable form. Also, if you want to absorb the CO2, for 1 pound of fuel you get like 3 pounds of CO2. You can absorb it into a solid and the density is like 3 times the density of the fuel. So with a lot of approximations you need container that has the same volume than the fuel tank to store the CO2, or even bigger if you absorb it in a liquid or much much much bigger as a gas. And you must empty/exchange the container when you refuel. And then you realize that it's better to use an electric car. |
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| ▲ | scientator 11 hours ago | parent | prev [-] | | https://mashable.com/article/ac-units-climate-change-carbon-... |
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| ▲ | reverendsteveii 8 hours ago | parent | prev [-] |
| okay but what's several million cubic meters of air times all the cars operating on earth right now? |
