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Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

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Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#101

Post by bhouston »

michaelbuckbee wrote: post #67
fulafel wrote: post #59

Earlier quoted context omitted.

Slight aside, anyone know why all the supposedly iot-oriented small arduino devices are IPv4-only? Is everyone deploying them in some kind of NATs + port forwards / upnp system or tunneled overlay IPv4 network using external gateway devices?

Genuine question: are Arduino's really for IOT or for prototyping? Not an expert, just read a lot about startups starting with a RaspPI or Arduino prototype for the Kickstarter or something and then getting "real" dedicated hardware for production.

Arduinos are not for production, but for prototyping, hobby projects.

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#102

Post by bhouston »

Hobohodo wrote: post #55
bhouston wrote: post #47

I would have just had the CO2 level read via a $8 I2C device connected to an Esp8266/Esp32 running Arduino. I would post the result to a web service in this fashion from the Esp8266: https://techtutorialsx.com/2016/07/21/esp8266-post-requests/ Then just setup a nice Graphana+Prometheus as a service, graphana.com is nice and can expose a Prometheus end point over basic http auth - easy to post to. Then you can setup a…

Would you be able to share where you might get such a cheap CO2 sensor/the name of it? I've had trouble finding them for less than £60 in the UK and would like to set one up.

I always check aliexpress.com https://www.aliexpress.com/wholesale?SearchText=co2+sensor+m...

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#103

Post by maxk42 »

AdrianB1 wrote: post #25
coldtea wrote: post #16

Earlier quoted context omitted.

> It sounds silly but it's scary how quickly levels rise when the windows are closed. It might be scary, but is it actually dangerous? It could just be that the levels shown, even if raised, are inconsequential. Basically wondering about the "Already changed my life" line. Are we all without one risk certain CO2 death every day, or is the parent overly worried over nothing (and opens windows without really a need for…

The "changed my life" is probably "I have one more thing to focus on for a while". As humans emit CO2 and your lungs are full of it, the danger exists if you run out of oxygen and get too much CO2, the kind of situation where you can get indoors only if you tape all your doors and windows creating an airproof seal.

It solved a chronic lethargy problem that resulted in me falling asleep randomly at inappropriate hours at home.

Literally -- not figuratively -- changed my life.

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#104

Post by maxk42 »

coldtea wrote: post #16
maxk42 wrote: post #8

Installed a CO2 monitor in my home two days ago. Already changed my life. It warns me when I need additional ventilation and even beeps if CO2 levels raise too high. It sounds silly but it's scary how quickly levels rise when the windows are closed.

> It sounds silly but it's scary how quickly levels rise when the windows are closed. It might be scary, but is it actually dangerous? It could just be that the levels shown, even if raised, are inconsequential. Basically wondering about the "Already changed my life" line. Are we all without one risk certain CO2 death every day, or is the parent overly worried over nothing (and opens windows without really a need for…

It was causing a narcolepsy-like condition which caused me to experience extreme drowsiness and lethargy and fall asleep at inappropriate hours in my apartment.

My doctors couldn't figure out what it was because every time I'd go get bloodwork done, I'd be out of the house and the symptoms would clear up. I thought it was due to age and that I was simply getting tired when I got home. It took me nearly two years to realize the fatigue didn't happen when I was spending the night somewhere else. I read an article on CO2 levels affecting quality of sleep a few days ago here on HN and it dawned on me that the symptoms weren't happening when I was out of my own apartment and I'd sealed and weather-stripped the apartment shortly before the symptoms began.

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#105

Post by maxk42 »

llampx wrote: post #9
maxk42 wrote: post #8

Installed a CO2 monitor in my home two days ago. Already changed my life. It warns me when I need additional ventilation and even beeps if CO2 levels raise too high. It sounds silly but it's scary how quickly levels rise when the windows are closed.

Which one did you get? I'm interested in getting one as well.

This one on Amazon: https://www.amazon.com/gp/product/B001PDGFR8/ref=ppx_yo_dt_b...

Looks like they're out of stock now, but it has a big label on the front that says co2meter.com, so you might want to check there.

I am not affiliated with that company.

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#106

Post by janekm »

aaaaaaaaaab wrote: post #64
RossM wrote: post #62

Earlier quoted context omitted.

Adafruit sell a 1-60,000 ppm equivalent-CO2 sensor for £15. https://www.adafruit.com/product/3709

This doesn't measure CO2 levels. It measures volatile organic compounds and calculates the amount of CO2 that would cause the same greenhouse effect. >The SGP30 does have built in calibration capabilities, note that eCO2 is calculated based on H2 concentration, it is not a 'true' CO2 sensor for laboratory use.

Not even that. It is designed for hvac applications and measures VOCs on the assumption that they are from human breath and have a corresponding increase in CO2 levels due to breath.

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#107

Post by slantyyz »

maxk42 wrote: post #8

Installed a CO2 monitor in my home two days ago. Already changed my life. It warns me when I need additional ventilation and even beeps if CO2 levels raise too high. It sounds silly but it's scary how quickly levels rise when the windows are closed.

I've had a CO2Meter monitor for about a year now, and I have mine connected to a Raspberry Pi. I use a node script to push readings to a database on my NAS, and to fire an IFTTT webhook to my Nest to turn on the fan when CO2 levels hit a certain threshold.

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#108

Post by dylan604 »

SketchySeaBeast wrote: post #83
WilliamEdward wrote: post #81

Earlier quoted context omitted.

Plants produce a net deficit of CO2, so you're correct but over a 24 hour period with proper lighting they will produce more oxygen than CO2. The important thing, however, is that they produce this CO2 at night at such an unbelievably slow rate that you wont be choking to death in your sleep, that's silly. If you fill a room with plants and cut out the lights, most CO2 produced will be from your cat sleeping on the f…

Apparently plants put out half the CO2 again over the night that they took in. I'm just thinking that either way they aren't that big of deal as far as oxygen/carbon dioxide production/consumption. Air filtration, possibly.

Depends on the number of plants. Growing up, my mom was a florist and we had an abundance of plants throughout the house. Wouldn't necessarily suggest going to that level, but plants do make for a much less sterile environment. Big green leafy plants are better air scrubbers and much easier to care for than cute dainty flowers.

Examples: https://www.google.com/search?hl=en-CA&authuser=0&biw=1345&b...

Depending on choice of pot and soil, most only need to be watered once a week. Even still, there are decorations that hold water to slow release for even extended times between watering. Great for vacations, or the forgetful.

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#109

Post by Bartweiss »

thinkcontext wrote: post #76
drankula3 wrote: post #65

Earlier quoted context omitted.

My wife is a respiratory therapist. When asked, she said higher-than-average CO2 is seen in COPD patients, and is compensated through an increase in metabolic bicarbonate production, countering the acidic properties of CO2. We are still entering unknown territories with such large populations getting exposed to higher CO2 levels, but she thinks we'll be fine.

I'm having trouble recounciling that with the study that shows cognitive decline, can you explain your wife's thinking?

The short answer is that we're great at compensating for CO2 variation, but only if it's constantly elevated for days or more.

The long answer:

I think the clarifying reference here is 'respiratory acidosis', which is the general name for what blood acidification that comes from CO2 exchange problems instead of internal sources. It's diagnosed as a disease when people exceed a threshold pH, but the body's behavior is the same before that. Acidosis is diagnosed in two forms, acute and chronic. Predictably, both represent the same problem of too-low blood pH, but acute is more extreme and shorter term. What's relevant here is the difference in subsequent outcomes.

Regardless of what's driving the acidification, the body responds first by making more bicarbonate, then by excreting more carbonic acid and reabsorbing more bicarbonate. The production response happens on the order of an hour, but heavily undercompensates for acidification. The reabsorption response happens over several days, and multiplies the effect of the first response for full compensation.

This makes the problem with acute acidosis obvious: you suffer symptoms much faster than you adjust. A weaker version of the same effect is what happens when you go into a high-CO2 space. Chronic acidosis, meanwhile, creates two different concerns:

First, can the body compensate for CO2 levels? If bicarbonate production is disrupted or acidification is very severe (e.g. late-stage emphysema), it's possible to exceed the bounds of compensation and end up with an extended form of the acute symptoms. For our purposes, though, this isn't a concern; at sub-disease levels, the only people who can't compensate probably can't produce bicarbonate at current levels either.

Second, does the compensation have health consequences? Chemically, we see slightly elevated serum levels of Ca and K, but even serious acidosis rarely requires any response. Experimentally, submarine atmospheres are substantially higher in CO2 than poorly-ventilated houses or global warming projections, but animal experiments show basically no effect and submariners don't show obvious problems.

Re: Show HN: I wanted to measure CO2 in my office, so I build a C++ WebServer/App

#110

Post by Bartweiss »

heavenlyblue wrote: post #91
TremendousJudge wrote: post #82

Earlier quoted context omitted.

Maybe it means that if you are _always_ exposed to high CO2 your body adjusts, but if you are sporadically exposed it does not? Kind of like living in the mountains vs going there occasionally

>> adjusts Only true if adjustment isn’t giving up higher functioning of the body for a less efficient metabolism.

Fortunately, we're really good at compensating for blood acidification. It's offset with higher bicarbonate levels and more excretion, which means the reaction uses carbonic acid and hydrogen to offset carbonic acid - pretty low-consequence to produce. Having more bicarbonate raises calcium and potassium levels slightly, but even when it's way outside of any normal exposure it doesn't seem to cause further effects.
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