Hacker News Reader

Comment by LargoLasskhyfv | Hacker News Reader

So. What are you going to do when it shows you levels of CO2 too high? Opening a can of Perry Air, search for https://duckduckgo.com/?q=air+quality+improvement+with+plant... , or what? Using it as an indicator of when to finally move elsewhere?

View on HN

Right now? Open the window :)

How is that helping when the outdoor CO2-levels are elevated too much?

(Unter Schmutzatmosphäre verkackt! https://en.wikipedia.org/wiki/Packaging_gas)

It still takes time for outdoor normal co2 level to reach those levels.

We gain 2 co2 per year.

And you can have an indoor garden

Plants + grow lamps. Get something easy to grow quickly indoors, say some random type of weed, and start letting it absorbing co2.

It is simply not feasible to lower co2 in a space with a few plants. Ventilation is the only method that works.

This is trivial to test. Just get a monitor, walk into a room with plants, close door, and start breathing. Check change in co2 after 15-30 min.

Vent the room, remove plants, repeat. Results should be equivalent.

Plants store co2 by growing. They do not grow quickly enough to deal with emissions from your breath.

To put a number on it, you exhale ~2.3lb of CO2 a day. You should also consider that much of a plants mass is water, so it would require a significant amount of plant matter to scrub the air.

I once did the math, and found that an algae tank can theoretically offset a person’s entire CO2 emissions but that it would require a large external tank and I was living in an apartment at the time.

There have been studies on indoor plants and air quality. The most well-known of which, I believe, was the NASA Clean Air Study [0]. The study suggested 1 plant per 100 sq. ft. but a space station obviously isn't the same thing as a dwelling.

[0]: https://en.wikipedia.org/wiki/NASA_Clean_Air_Study

That’s air quality, not co2. Air quality usually means particulates and VOCs.

Oof, you're totally right. Thanks for the correction!

Once you have the carbon in biomass, what do you do with it? Dry it out and heat it enough to make biochar?

Very good question. I had two avenues in mind, fungus and compost.

Don't plants take oxygen and release CO2 at night?

They do and they don't. The net result of a growing plant is the absorption of CO2 and H2O to create O2 and various hydrocarbons, oxygen and plant matter. The carbon is fixed in the body of the plant. But i did mention grow lamps. Keep them lit and there is no night.

Plants still need to use the glucose, though. It's misleading to say that plants produce CO2 at night (since they produce it all the time); rather, they become a net CO2 producer at night because they're not offsetting it with photosynthesis.

I'm not convinced that grow lamps are an effective way to offset that, since photosynthetic efficiency is fairly low (3-4%), and the electricity for the lamp has to come from somewhere. Not to mention that lamps (even LEDs) are also fairly lossy. I'm also not convinced that's even worth optimizing.

This is about indoor air pollution. I assume the coal-fired power plant is at least not in the same building.

YES! Many websites recommend having plants in the sleeping room to produce O2. Plants actually consume O2 and produce CO2 at night, through not very much.

I sleep terribly at home and I am trying out to find out why. Two people and a dog in a room should not be an issue if the window is a little bit open.

you might want to consider temperature as a possible culprit. a lower temperature is a signal to the body to curl up and sleep, and a consistently cool (relative) temperature keeps you in that state. when we wake up, our bodies ramp up our metabolism/temperature to rouse us out of slumber. i know i'm ready for sleep when i impulsively reach for the sheets. with two people, a dog, and only a cracked window, the temperature might be rising above your sleep signal during the night (i wake up often in the middle of the night and can literally feel the heat rising as i gain consciousness).

Open a window. Those grow lamps use energy and might contribute to the problem, depending on where you live.

The reason energy use is a problem is the electricity production.

And electricity production might not be that carbon-intensive depending on the place, hence "depending on where you live" :)

I feel like I have to combust some random type of weed to that, indoors even! :-)

Burning it back into CO2 is certainly more environmentally friendly than dumping it to decompose into methane.

Excellent reasoning. I need to remember that one.

You could capture and consume the methane as part of your home's energy cycle.

But composting both avoids methane production and sequesters carbon.

My understanding is that aerobic composting does not produce methane, but anaerobic composting does. If you're doing the composting at home you can set it up for aerobic composting. But if the waste material is going into a landfill, it's more likely to end up in an anaerobic composting process. Unless you happen to live in one of the few regions that actually have people separate out different types of waste products properly.

Invent a way to put a square peg in a round hole, rapidly.

Reply on news.ycombinator.com