6 ms·

Pittsburgh Airport installs an algae air purifier

81 points by respinal 4y ago

pyuser583 4y ago
- dang 4y ago
  Maybe so, but please don't post unsubstantive comments to HN. We're trying for something else here. It's particularly important not to do this when there aren't any comments yet, because threads are so sensitive to initial conditions.
  - graderjs 4y ago
    Burning the midnight oil
ajmurmann 4y ago
This is super interesting! Sounds from the article like the main point is to remove CO2 from the air to improve air for humans. That's already really exciting. In essence it's a CO2 scrubber right? So how does this compare to devices built with the goal to remove CO2 with the goal to reduce climate change? Edit: To answer my own question, this probably does little. They have a home use version that supposedly removes as much Co2 as twenty indoor plants. The paper linked below had three most efficient plant remove about 17% of Co2 in a cubic meter of air with optimal light conditions. So twenty of those wouldn't have much impact in a reasonably sized dwelling. That's assuming it's equivalent to the most efficient plant and great lighting. I cannot imagine the much larger installation at the airport making much of a difference either given the massive amount of air. https://www.researchgate.net/publication/315968651_Effectiveness_of_Indoor_Plant_to_Reduce_CO_2_in_Indoor_Environment https://www.researchgate.net/publication/315968651_Effective...
- kolinko 4y ago
  Good math. Another way to ballpark this - the airport tank holds 500 liters of spirulina. Algae extract around 0.5kg co2 per 1000 liters ( https://mdpi-res.com/d_attachment/sustainability/sustainability-14-03801/article_deploy/sustainability-14-03801-v2.pdf?version=1648090121 https://mdpi-res.com/d_attachment/sustainability/sustainabil... ). So this tank removes around 0.25kg of co2 per day. By comparison, an average human exhales 1kg co2 per day. So you need four of those tanks to offset a single passenger passing by. This does virtually nothing for the air freshness, and is possibly not even carbon negative if you were to count emissions from the device cleanup and algae storage. Green washing at it’s finest.
  - ac29 4y ago
    I would assume the electricity used to power the pumps and lights ends up emitting substantially more than 250g of CO2 per day as well.
    - dylan604 4y ago
      If only there was a large parcel of land nearby to an airport terminal where a renewable power source could be installed. Hmm, where could we find a large piece of relatively flat land with little to no trees to shade the sunlight? Hell, you could even cover the remote parking areas bringing extra value by providing covered parking and still leave the majority of that flat, cleared, open space unadulterated.
      - mwint 4y ago
        I’m guessing they don’t want to put stuff in the areas around runways, because that’s where planes go when something bad happens. I wouldn’t want to be escaping a plane directly into a chopped-up field of HV solar panels.
  - deleted 4y ago
    [deleted]
  - domoritz 4y ago
yread 4y ago
Hah I was asking about just that 12 days ago https://news.ycombinator.com/item?id=33027184 https://news.ycombinator.com/item?id=33027184
tkanarsky 4y ago
Based on the photo, it seems more of a showpiece than an actually practical way of filtering large quantities of air. Those bubble columns are at most a few liters of air per minute -- not much more than your usual aquarium pump -- when large air purifiers are in the hundreds or even thousands of cubic feet per minute. I just can't imagine passing that much air through the columns without sending greenish water all over unsuspecting passengers. Unless this treated air has a synergistic effect on the surrounding air, like negative ions or ozone, this won't make the air significantly cleaner. It does look cool, though.
- blitzar 4y ago
  #AD
aitchnyu 4y ago
Any power consumption figures for a room of X people? I have to bombard my aquarium with powerful lights and co2 injection to get some pearling (oxygen bubbles). I would also imagine the lights to be blue+red peak grow lights to optimize photosynthesis and the glass tubes to be thinner to minimize attenuation of light in liquid.
bmitc 4y ago
This seems like a potentially nice thing for a home office or bedroom. Does anyone have any experience with their home version? https://algenair.com/ https://algenair.com/
- ryanmerket 4y ago
  I use it in my office. Don't really notice a difference. I should get a CO2 reader and test it out.
  - blitzar 4y ago
    Do you feel more mental clarity - reduced brain fog - less sources of headaches. These seem like they were specifically chosen due to them being things which you cant really test or quantify.
  - bmitc 4y ago
    I really like the idea, but it does seem like a hard thing to be sure of. I suppose a secondary question is: does it look nice? :)
    - thesh4d0w 4y ago
      I liked the idea until I realized it wasn't self sustaining and needs a monthly subscription to replace the algae =(
      - bmitc 4y ago
        In some ways I don't mind it since it seems expected and I also like the idea of using the remains as compost feed. But I was a little worried about the expense of renewing it plus the waste from doing so. It looks like the algae and nutrients come in plastic bottles.
JohnJamesRambo 4y ago
I have my doubts about this. In my experience, a house full of cannabis plants photosynthesizing full tilt under 15,000 watts of lights would still show elevated CO2 when two people went to it and tended it. Maybe the algae get around that, but I need to see some numbers. >A human breathes about 9.5 tonnes of air in a year, but oxygen only makes up about 23 per cent of that air, by mass, and we only extract a little over a third of the oxygen from each breath. That works out to a total of about 740kg of oxygen per year. Which is, very roughly, seven or eight trees' worth.
- pooper 4y ago
  This is going off topic but what an interesting idea... Can plants work day and night if you give them light 24x7? I assume they don't need to rest or get tired?
  - georgyo 4y ago
    Plants do indeed have day night cycles, so they do need rest. Just Google plant day night cycle.
  - derrasterpunkt 4y ago
    This depends, as far as I know, if the plant is doing C-3 or C-4 photosynthesis.
WalterBright 4y ago
I bought a CO2 meter, and discovered my office had elevated CO2 levels (sometimes going over 1000). Cracking a window solved the problem. Want to reduce CO2 levels outside? Plant trees. They're solar-powered green machines, turning CO2 into building materials, paper, and fuel.
- smt88 4y ago
  > Want to reduce CO2 levels outside? Plant trees. This thread is about indoor air pollution. Trees aren't going to help with that. The best way to reduce it is to open a window. For outdoor air pollution, planting trees can actually increase it[1]. Even in ideal conditions, planting trees is not nearly enough to stop climate change. The best way to fix the CO2 problem is stop producing it, not to try to clean it up. 1. https://www.bbc.com/future/article/20200521-planting-trees-doesnt-always-help-with-climate-change https://www.bbc.com/future/article/20200521-planting-trees-d...
  - WalterBright 4y ago
    > planting trees is not nearly enough to stop climate change The solution will be a mix of approaches, none of them in isolation doing the whole job. > For outdoor air pollution, planting trees can actually increase it Only if by doing so you remove vegetation to plant them.
    - smt88 4y ago
      > Only if by doing so you remove vegetation to plant them. That is not correct. Read the article I linked that explains it. Biology isn't as simple as "CO2 => biomass".
      - msandford 4y ago
        I read the whole article and I can't find the part that backs up your statement. Not saying it might not be there, but telling people to figure it out on their own isn't super helpful. In fact most of the article seems to agree that planting trees is a net good for removing CO2 and that the biggest problem is finding enough room to plant all the trees that are needed.
martopix 4y ago
If you really want to have a less CO2-heavy stuffy indoor air, what you can use is an air-to-air heat exchanger. The idea is to get fresh air from outside, but transfer heat from the outgoing Co2-rich air to the incoming fresh air so you don't waste the heating (reverse in case of air conditioning, I suppose). If the problem is Co2 in the outdoor air, I'm afraid that's a much bigger problem that you're not gonna solve with a tank.
- nix23 4y ago
  CO2 or Oxygen levels are normally never a problem, not even on mount Everest (where the air pressure is the problem). It's for sure not a solution but an interesting research field to remove toxic chemicals...for long duration spaceflight/bases ;) https://en.wikipedia.org/wiki/NASA_Clean_Air_Study https://en.wikipedia.org/wiki/NASA_Clean_Air_Study
  - valenceelectron 4y ago
    The crucial part of this study is the following quote: "These results are not applicable to typical buildings, where outdoor-to-indoor air exchange already removes VOCs at a rate that could only be matched by the placement of 10–1000 plants/m2 of a building’s floor space." In general, the amount of plants needed is just too high to be practical. At least among those plants tested in this study. This also applies to plants commonly sold as "air cleaners" (the common ones were all tested in this study). They do little to nothing for non-sealed rooms. Specific algea may be better suited.
    - deleted 4y ago
      [deleted]
    - nix23 4y ago
      That's why i wrote "moonbase" where your fresh veggies could also clean the air. But yes algea are maybe better if you have the power to circulate them, pressured air to blow it truth and a filter to take the dead ones out, bacteria etc in check, earlier or later your water will start to foul otherwise.
maxrev17 4y ago
Does elevated co2 even cause a problem for humans?
- ipqk 4y ago
  Yes, less o2 reaches the brain. We experience cognitive decline and/or have worse sleep.
goldforever 4y ago

81 points by respinal 4y ago

dang 4y ago
Maybe so, but please don't post unsubstantive comments to HN. We're trying for something else here. It's particularly important not to do this when there aren't any comments yet, because threads are so sensitive to initial conditions.
- graderjs 4y ago
  Burning the midnight oil

This is super interesting! Sounds from the article like the main point is to remove CO2 from the air to improve air for humans. That's already really exciting. In essence it's a CO2 scrubber right? So how does this compare to devices built with the goal to remove CO2 with the goal to reduce climate change? Edit: To answer my own question, this probably does little. They have a home use version that supposedly removes as much Co2 as twenty indoor plants. The paper linked below had three most efficient plant remove about 17% of Co2 in a cubic meter of air with optimal light conditions. So twenty of those wouldn't have much impact in a reasonably sized dwelling. That's assuming it's equivalent to the most efficient plant and great lighting. I cannot imagine the much larger installation at the airport making much of a difference either given the massive amount of air. https://www.researchgate.net/publication/315968651_Effectiveness_of_Indoor_Plant_to_Reduce_CO_2_in_Indoor_Environment https://www.researchgate.net/publication/315968651_Effective...

kolinko 4y ago
Good math. Another way to ballpark this - the airport tank holds 500 liters of spirulina. Algae extract around 0.5kg co2 per 1000 liters ( https://mdpi-res.com/d_attachment/sustainability/sustainability-14-03801/article_deploy/sustainability-14-03801-v2.pdf?version=1648090121 https://mdpi-res.com/d_attachment/sustainability/sustainabil... ). So this tank removes around 0.25kg of co2 per day. By comparison, an average human exhales 1kg co2 per day. So you need four of those tanks to offset a single passenger passing by. This does virtually nothing for the air freshness, and is possibly not even carbon negative if you were to count emissions from the device cleanup and algae storage. Green washing at it’s finest.
- ac29 4y ago
  I would assume the electricity used to power the pumps and lights ends up emitting substantially more than 250g of CO2 per day as well.
  - dylan604 4y ago
    If only there was a large parcel of land nearby to an airport terminal where a renewable power source could be installed. Hmm, where could we find a large piece of relatively flat land with little to no trees to shade the sunlight? Hell, you could even cover the remote parking areas bringing extra value by providing covered parking and still leave the majority of that flat, cleared, open space unadulterated.
    - mwint 4y ago
      I’m guessing they don’t want to put stuff in the areas around runways, because that’s where planes go when something bad happens. I wouldn’t want to be escaping a plane directly into a chopped-up field of HV solar panels.
- deleted 4y ago
  [deleted]
- domoritz 4y ago

yread 4y ago

Hah I was asking about just that 12 days ago https://news.ycombinator.com/item?id=33027184 https://news.ycombinator.com/item?id=33027184

tkanarsky 4y ago

Based on the photo, it seems more of a showpiece than an actually practical way of filtering large quantities of air. Those bubble columns are at most a few liters of air per minute -- not much more than your usual aquarium pump -- when large air purifiers are in the hundreds or even thousands of cubic feet per minute. I just can't imagine passing that much air through the columns without sending greenish water all over unsuspecting passengers. Unless this treated air has a synergistic effect on the surrounding air, like negative ions or ozone, this won't make the air significantly cleaner. It does look cool, though.

blitzar 4y ago
#AD

aitchnyu 4y ago

Any power consumption figures for a room of X people? I have to bombard my aquarium with powerful lights and co2 injection to get some pearling (oxygen bubbles). I would also imagine the lights to be blue+red peak grow lights to optimize photosynthesis and the glass tubes to be thinner to minimize attenuation of light in liquid.

bmitc 4y ago

This seems like a potentially nice thing for a home office or bedroom. Does anyone have any experience with their home version? https://algenair.com/ https://algenair.com/

ryanmerket 4y ago
I use it in my office. Don't really notice a difference. I should get a CO2 reader and test it out.
- blitzar 4y ago
  Do you feel more mental clarity - reduced brain fog - less sources of headaches. These seem like they were specifically chosen due to them being things which you cant really test or quantify.
- bmitc 4y ago
  I really like the idea, but it does seem like a hard thing to be sure of. I suppose a secondary question is: does it look nice? :)
  - thesh4d0w 4y ago
    I liked the idea until I realized it wasn't self sustaining and needs a monthly subscription to replace the algae =(
    - bmitc 4y ago
      In some ways I don't mind it since it seems expected and I also like the idea of using the remains as compost feed. But I was a little worried about the expense of renewing it plus the waste from doing so. It looks like the algae and nutrients come in plastic bottles.

JohnJamesRambo 4y ago

I have my doubts about this. In my experience, a house full of cannabis plants photosynthesizing full tilt under 15,000 watts of lights would still show elevated CO2 when two people went to it and tended it. Maybe the algae get around that, but I need to see some numbers. >A human breathes about 9.5 tonnes of air in a year, but oxygen only makes up about 23 per cent of that air, by mass, and we only extract a little over a third of the oxygen from each breath. That works out to a total of about 740kg of oxygen per year. Which is, very roughly, seven or eight trees' worth.

pooper 4y ago
This is going off topic but what an interesting idea... Can plants work day and night if you give them light 24x7? I assume they don't need to rest or get tired?
- georgyo 4y ago
  Plants do indeed have day night cycles, so they do need rest. Just Google plant day night cycle.
- derrasterpunkt 4y ago
  This depends, as far as I know, if the plant is doing C-3 or C-4 photosynthesis.

WalterBright 4y ago

I bought a CO2 meter, and discovered my office had elevated CO2 levels (sometimes going over 1000). Cracking a window solved the problem. Want to reduce CO2 levels outside? Plant trees. They're solar-powered green machines, turning CO2 into building materials, paper, and fuel.

smt88 4y ago
> Want to reduce CO2 levels outside? Plant trees. This thread is about indoor air pollution. Trees aren't going to help with that. The best way to reduce it is to open a window. For outdoor air pollution, planting trees can actually increase it[1]. Even in ideal conditions, planting trees is not nearly enough to stop climate change. The best way to fix the CO2 problem is stop producing it, not to try to clean it up. 1. https://www.bbc.com/future/article/20200521-planting-trees-doesnt-always-help-with-climate-change https://www.bbc.com/future/article/20200521-planting-trees-d...
- WalterBright 4y ago
  > planting trees is not nearly enough to stop climate change The solution will be a mix of approaches, none of them in isolation doing the whole job. > For outdoor air pollution, planting trees can actually increase it Only if by doing so you remove vegetation to plant them.
  - smt88 4y ago
    > Only if by doing so you remove vegetation to plant them. That is not correct. Read the article I linked that explains it. Biology isn't as simple as "CO2 => biomass".
    - msandford 4y ago
      I read the whole article and I can't find the part that backs up your statement. Not saying it might not be there, but telling people to figure it out on their own isn't super helpful. In fact most of the article seems to agree that planting trees is a net good for removing CO2 and that the biggest problem is finding enough room to plant all the trees that are needed.

martopix 4y ago

If you really want to have a less CO2-heavy stuffy indoor air, what you can use is an air-to-air heat exchanger. The idea is to get fresh air from outside, but transfer heat from the outgoing Co2-rich air to the incoming fresh air so you don't waste the heating (reverse in case of air conditioning, I suppose). If the problem is Co2 in the outdoor air, I'm afraid that's a much bigger problem that you're not gonna solve with a tank.

nix23 4y ago
CO2 or Oxygen levels are normally never a problem, not even on mount Everest (where the air pressure is the problem). It's for sure not a solution but an interesting research field to remove toxic chemicals...for long duration spaceflight/bases ;) https://en.wikipedia.org/wiki/NASA_Clean_Air_Study https://en.wikipedia.org/wiki/NASA_Clean_Air_Study
- valenceelectron 4y ago
  The crucial part of this study is the following quote: "These results are not applicable to typical buildings, where outdoor-to-indoor air exchange already removes VOCs at a rate that could only be matched by the placement of 10–1000 plants/m2 of a building’s floor space." In general, the amount of plants needed is just too high to be practical. At least among those plants tested in this study. This also applies to plants commonly sold as "air cleaners" (the common ones were all tested in this study). They do little to nothing for non-sealed rooms. Specific algea may be better suited.
  - deleted 4y ago
    [deleted]
  - nix23 4y ago
    That's why i wrote "moonbase" where your fresh veggies could also clean the air. But yes algea are maybe better if you have the power to circulate them, pressured air to blow it truth and a filter to take the dead ones out, bacteria etc in check, earlier or later your water will start to foul otherwise.

maxrev17 4y ago

Does elevated co2 even cause a problem for humans?

ipqk 4y ago
Yes, less o2 reaches the brain. We experience cognitive decline and/or have worse sleep.

goldforever 4y ago