8 ms·

I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over

I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over 1000ppm IIRC. Ever since then I've made sure to set my AC system to run the "house fan" for 15 minutes or so every hour at night just to circulate the air in the house, and while the numbers went down significantly, anecdotally I swear that I wake up easier in the mornings now. Another surprising place that really high CO2 concentrations show up? The inside of full face motorcycle helmets when at a stop. IIRC they quickly reach as high as 20,000ppm! There is also some speculation that full-face motorcycle helmets that stay closed in an accident are more dangerous in some ways, as the high CO2 concentrations in the helmet can be really dangerous to an unconscious person's brain function.

Cthulhu_ 7y ago
Helmets? That's interesting; I tend to open the visor a bit when at a stop, it gets really warm in there really fast. I know you shouldn't try to take off a helmet in case of an accident, but is opening the visor at least okay?
- Klathmon 7y ago
  Yeah ever since I read that, I crack the visor or open it when i'm sitting still. And for opening the visor in accidents, I'm no expert but I believe it would be safe to do if you can do it without moving their head. IIRC the reason you don't want to take off the helmet is because you could strain their neck doing so. If you could move the visor without moving their head, it probably won't hurt, but at the same time I'm not sure if I'd worry about that in this kind of situation (having seen a motorcycle accident, the amount of co2 that person is breathing is, to me anyway, far down the list behind "call 911" and "make sure they don't get run over again"). I think the findings were more to try and get the helmet manufacturers to design systems which let more air in during an accident or when stopped. [1] has the study I remember reading about, and it turns out that according to their abstract, opening the visor at a stop has little effect on average! So maybe my behaviour of cracking the visor isn't doing much... [1] https://www.ncbi.nlm.nih.gov/pubmed/15893291 https://www.ncbi.nlm.nih.gov/pubmed/15893291
  - leereeves 7y ago
    Moving an unconscious person's head or neck can cause paralysis (if they have a spinal injury). Don't do it without training. In a city it's almost surely best just to wait for the EMTs.
- snarf21 7y ago
  Unless it is terribly cold, I always run a small crack at low speeds. My helmet has a notch that is just a half inch of crack. At high speeds the vents pull air through. It is funny because I never thought about CO2, just that it is too freaking hot.
- blattimwind 7y ago
  > I know you shouldn't try to take off a helmet in case of an accident, At least here in Germany this advice is considered outdated and people in (mandatory for driving) first aid courses get taught a simple technique to remove a helmet safely (ideally with two people). Reason being is that with the helmet on it is harder to monitor breathing and impossible / very difficult to do CPR, and the helmet will also interfere with the stable side position.
  - GuiA 7y ago
    It’s interesting to see how differently first aid is taught across countries. Eg the last training I did in the US (California), I was surprised by two things that I had not encountered when I was trained in France: - a big concern around pathogens - always have gloves with you and put them on when administering first aid especially if the person is bleeding; use a mouth dam for mouth to mouth and if you don’t have one don’t do mouth to mouth, just chest compressions, etc - training first aid responders around what to do when a person needing medical attention tells them not to help because they don’t have health insurance (this point was repeated numerous times by the EMT training us, saying it was routine for them to have to deal with it)
    - em-bee 7y ago
      what are you supposed to if the person claims they have no insurance?
      - PeterisP 7y ago
        If the person is able to tell you that they have no insurance, this by itself means they're able to talk reasonably, this means they are conscious and can breathe and so (absent heavy ongoing bleeding e.g. from a gunshot wound) they aren't dying right now - so urgent emergency healthcare isn't really required. If they can move on their own, then they can get to the clinic of their choice themselves if and when they choose to; if they can't (which can be caused by anything from a sprained ankle to a fractured hip) then they still may prefer to be delivered to the hospital by family&friends or a taxi instead of paying thousands for an ambulance delivery.
- Shivetya 7y ago
  Helmets, hell think face masks people buy at the store to protect themselves from the lawn while cutting it. I tried one, felt like I was suffocating. full face helmets can at times have the same effect if you bundle up to well during winter but I would be loathe to give it up
- lstodd 7y ago
  What's your model? I used to ride with a just-a-bit opened visor because it was so hot in the city, with all the traffic and all, (and the beard didn't help the air flow) so I ended with eye infection because of the dust ingress. So I just bought one with better vents (and audio). Worth every $ even though I had to patch the audio circuitry a bit. Maybe you should consider upgrading.
- skeleton 7y ago
  Yeah I always open my visor when I'm stopped/riding slowly for longer than I can comfortably hold my breath. Depending on the temperature outside, if I don't open my visor it will fog up real fast.
SilasX 7y ago
Is that why they seem to revert to the childlike state where they think it’s fun to rev the engine as loud as they can?
kurthr 7y ago
Exhaled breath is about 3.8% or 38000ppm so (20000) that's really high! I'm not too surprised since the turnover rate through a few small holes with a relatively large volume is bad. Reducing the facial volume would help a lot as each breath would expel more CO2 as a fractional percentage. It seems that any sort of face covering or even significant exercise could raise your ambient CO2 level well above 1000ppm. I'm a bit surprised that levels 38-60x below our exhalation % (and it's not lack of O2, because you use up less than 10%/breath) has such a significant effect. The one thing that may drive it is that the efficiency of lung ab/desorption goes roughly as the square of concentration so a 2% change in CO2 concentration might be enough to have an effect on O2 and blood pH.
- Klathmon 7y ago
  I found the study I read, and I'll re-link it here, it is eye opening to say the least! https://www.ncbi.nlm.nih.gov/pubmed/15893291 https://www.ncbi.nlm.nih.gov/pubmed/15893291
  - kurthr 7y ago
    Really interesting article... all the numbers are completely believable, but seem really high based on the conference room effects at 0.1% They even refer to a person without a helmet in still air as being at 2000ppm, which is comparable to the worst tested "school house" data. I'd argue that if there is an effect here it isn't the O2 concentration since a 1% change in atmospheric pressure happens at about 275ft. That's a pretty small hill! A 1000ppm change in 02 partial pressure happens in about 30C temperature change. Really, if this is a real effect it better be actually due to some effect of C02 concentration.
  - inetknght 7y ago
    Is there a link for the Elsevier-disabled people?
    - Vinnl 7y ago
      Unfortunately Unpaywall (tip: install the browser extension!) doesn't find any: https://unpaywall.org/10.1016/j.apergo.2005.01.018 https://unpaywall.org/10.1016/j.apergo.2005.01.018 So unless you're willing to go the illegal route through Sci-Hub, I'm afraid you're out of luck.
burger_moon 7y ago
I wonder what the number is for people who wear respirators for dust/fumes. There's the paper masks people are most familiar with and the charcoal canisters for working with chemicals. Since it's sealed off would it be even higher than a motorcycle helmet?
- jdavis703 7y ago
  There’s probably all kinds of confounding factors here, but on high pollution days (code purple air quality) when I’m bicycling I need to take my N95 mask off every few minutes for “fresh air.”
jak92 7y ago
> "house fan" for 15 minutes or so every hour at night just to circulate the air in the house, Depending on your climate, this could significantly raise the humidity in your house. Reason is that moisture from the AC coil are wet after the AC turns off. Typically drips off into the pan until next time AC cycles. If you run the fan you will then evaporate into the air circulating some of the moisture just removed.
- Klathmon 7y ago
  I live in florida, so I'm well accustomed to the humidity! But thanks for the tip, I actually hadn't thought about that. Part of my home automation system is humidity sensors as well, and while they do spike over 65% sometimes (probably when we have the windows open), they stay around 55% to 60% for the past 30 days. Since I'm only running that fan cycle at night, when the AC tends not to run or not run as much, I'm guessing that helps mitigate the effects of that.
  - deleted 7y ago
    [deleted]
- asdkhadsj 7y ago
  Doesn't that heavily depend on the design of the AC system? I know nothing here, so this is heavily a question. I ask because I have a heat pump for cooling/heating, but the furnace is the blower. I thought when the fan ran, it pulled from the outdoor intake which is in a very different location from the actual heat pump coils. Thoughts?
  - jak92 7y ago
    The air handler uses inside air only. The compressor heat pump is outside and either runs its cycle strictly on outside air
- abfan1127 7y ago
  that moisture came from inside the house. When it drips, it usually drains outside the home. Perhaps it just pedantic, but it won't raise humidity, but it may lower less.
castratikron 7y ago
I monitored the CO2 in my bedroom every second for three months and I found results similar to you. If I was sitting right next to the sensor in the evening it would go up to about 1900 ppm. Cracking open the window for an hour or so eventually brought things down to the 500ppm range. What was interesting is how fast the ppm increases when someone enters the room. I would plot the data and see a blip on the graph when I entered. It was within seconds of entering.
- colechristensen 7y ago
  I noticed the same when I am sitting near the sensor. I'm thinking though that it is partially due to me essentially breathing onto the sensor and the sensor dynamics having an averaging function so that I'm not sure what the sensor reports and what I breathe in are the same. Repositioning the sensor so it wasn't in the "line of sight" of my breath changed the readings significantly.
  - castratikron 7y ago
    Here's a plot. The peaks are when I was in my apartment. The gap in the middle of February was when I went on vacation. https://imgur.com/a/HtyhTzo https://imgur.com/a/HtyhTzo
    - JohnJamesRambo 7y ago
      That is really cool. Thanks for sharing, I love it when people collect data.
olivermarks 7y ago
Your post has made me consider getting a C02 monitor, will something as simple as this 20 buck Chinese version suffice? https://www.newegg.com/Product/Product.aspx?Item=9SIADJN8NP4860-9SIADJN8NP4860&gclid=CjwKCAjw_MnmBRAoEiwAPRRWW1Dv2zvRP-y-ajNDezjPEmJ0RMZDDzJpZRj0kpjceEO3CeQm0yIwqRoCW18QAvD_BwE&gclsrc=aw.ds https://www.newegg.com/Product/Product.aspx?Item=9SIADJN8NP4... Seems a useful thing to have. Separately it is very stressful being on stage at conferences that are stuffy with no fresh air, hot stage lights and probably very low oxygen. I had a friend who did press ups before going on stage to energize herself as the tech conference chair and raise the energy level of the sleepy audience - she got really out of breath!
- rootusrootus 7y ago
  IIRC the thing to be aware of is that a monitor that actually measures CO2 is going to cost several hundred dollars. The cheap ones don't measure CO2, but some kind of VOC as a proxy. So depending on the source of the CO2, they can be more or less accurate. Something to research. I'm not an expert, just someone who recently did some shopping for CO2 monitors for my home.
  - olivermarks 7y ago
    Thanks!
  - tolmasky 7y ago
    What did you end up buying?
    - rootusrootus 7y ago
      I didn't. Part of my requirements are that I can tie the device into my home automation. After doing a lot of digging and not finding something I wanted, I shelved the idea of adding CO2 sensors to my house for now. Decided instead to just assume CO2 was high, and I'm having a whole-house HRV installed in a few months.
- Klathmon 7y ago
irrational 7y ago
How does kissing affect CO2 levels? I know I've done some stupid things after kissing.
- bacon_waffle 7y ago
  Anecdata, but since I've started wearing SCUBA gear to meetings, I haven't been kissed once. Maybe it's more about high CO2 levels leading to kissing?
laythea 7y ago
"...high CO2 concentrations in the helmet can be really dangerous to an unconscious person's brain function" Yes but no helmet is even worse for an unconscious person's brain function :)
- Klathmon 7y ago
  Oh absolutely! I hope I'm not coming across as advocating for people to not wear helmets! I just thought it was a very interesting study and that helmet manufacturers could possibly find ways to mitigate it.
xur17 7y ago
> I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over 1000ppm IIRC. Any recommendations on CO2 monitors?
- MichaelDickens 7y ago
  I don't have any domain knowledge on CO2 monitors, but I use this one: https://smile.amazon.com/gp/product/B01FYWU2IS/ https://smile.amazon.com/gp/product/B01FYWU2IS/ It's a greenhouse CO2 monitor, which is the most common kind. I've heard that they're not as accurate as CO2 monitors that are designed for humans, but those tend to be much more expensive.
- rectangletangle 7y ago
  I always sleep with the window open, because the fresh air feels nice. In evolutionary terms, you could speculate that the nice feeling of fresh air could be an instinctual response directing the organism to seek higher quality air.
- gustavam 7y ago
  I did quite a lot of research trying to find the best CO2 sensor that would also do humidity/temperature. CaDi by nuwave* is what I settled on. An Irish company. I've been using it for a week now and it is working great! Things that surprised me: the difference it makes if I leave all the internal doors open in the apartment, not just the bedroom door. That even leaving one window open just a crack will help with ventilation. And of course how quickly a room with couple of people in it can go above 3000ppm CO2. *https://nuwavesensors.com/product/cadi-ci-100/ https://nuwavesensors.com/product/cadi-ci-100/
calvinbhai 7y ago
As a full face helmet proponent and user (since I started riding motorcycles in India), your comment really makes sense. This is something I used to do almost on instinct,usually at lower speeds (because the helmet had a sort of an intake and a vent that worked well at higher speeds).

Cthulhu_ 7y ago

Helmets? That's interesting; I tend to open the visor a bit when at a stop, it gets really warm in there really fast. I know you shouldn't try to take off a helmet in case of an accident, but is opening the visor at least okay?

Klathmon 7y ago
Yeah ever since I read that, I crack the visor or open it when i'm sitting still. And for opening the visor in accidents, I'm no expert but I believe it would be safe to do if you can do it without moving their head. IIRC the reason you don't want to take off the helmet is because you could strain their neck doing so. If you could move the visor without moving their head, it probably won't hurt, but at the same time I'm not sure if I'd worry about that in this kind of situation (having seen a motorcycle accident, the amount of co2 that person is breathing is, to me anyway, far down the list behind "call 911" and "make sure they don't get run over again"). I think the findings were more to try and get the helmet manufacturers to design systems which let more air in during an accident or when stopped. [1] has the study I remember reading about, and it turns out that according to their abstract, opening the visor at a stop has little effect on average! So maybe my behaviour of cracking the visor isn't doing much... [1] https://www.ncbi.nlm.nih.gov/pubmed/15893291 https://www.ncbi.nlm.nih.gov/pubmed/15893291
- leereeves 7y ago
  Moving an unconscious person's head or neck can cause paralysis (if they have a spinal injury). Don't do it without training. In a city it's almost surely best just to wait for the EMTs.
snarf21 7y ago
Unless it is terribly cold, I always run a small crack at low speeds. My helmet has a notch that is just a half inch of crack. At high speeds the vents pull air through. It is funny because I never thought about CO2, just that it is too freaking hot.
blattimwind 7y ago
> I know you shouldn't try to take off a helmet in case of an accident, At least here in Germany this advice is considered outdated and people in (mandatory for driving) first aid courses get taught a simple technique to remove a helmet safely (ideally with two people). Reason being is that with the helmet on it is harder to monitor breathing and impossible / very difficult to do CPR, and the helmet will also interfere with the stable side position.
- GuiA 7y ago
  It’s interesting to see how differently first aid is taught across countries. Eg the last training I did in the US (California), I was surprised by two things that I had not encountered when I was trained in France: - a big concern around pathogens - always have gloves with you and put them on when administering first aid especially if the person is bleeding; use a mouth dam for mouth to mouth and if you don’t have one don’t do mouth to mouth, just chest compressions, etc - training first aid responders around what to do when a person needing medical attention tells them not to help because they don’t have health insurance (this point was repeated numerous times by the EMT training us, saying it was routine for them to have to deal with it)
  - em-bee 7y ago
    what are you supposed to if the person claims they have no insurance?
    - PeterisP 7y ago
      If the person is able to tell you that they have no insurance, this by itself means they're able to talk reasonably, this means they are conscious and can breathe and so (absent heavy ongoing bleeding e.g. from a gunshot wound) they aren't dying right now - so urgent emergency healthcare isn't really required. If they can move on their own, then they can get to the clinic of their choice themselves if and when they choose to; if they can't (which can be caused by anything from a sprained ankle to a fractured hip) then they still may prefer to be delivered to the hospital by family&friends or a taxi instead of paying thousands for an ambulance delivery.
Shivetya 7y ago
Helmets, hell think face masks people buy at the store to protect themselves from the lawn while cutting it. I tried one, felt like I was suffocating. full face helmets can at times have the same effect if you bundle up to well during winter but I would be loathe to give it up
lstodd 7y ago
What's your model? I used to ride with a just-a-bit opened visor because it was so hot in the city, with all the traffic and all, (and the beard didn't help the air flow) so I ended with eye infection because of the dust ingress. So I just bought one with better vents (and audio). Worth every $ even though I had to patch the audio circuitry a bit. Maybe you should consider upgrading.
skeleton 7y ago
Yeah I always open my visor when I'm stopped/riding slowly for longer than I can comfortably hold my breath. Depending on the temperature outside, if I don't open my visor it will fog up real fast.

SilasX 7y ago

Is that why they seem to revert to the childlike state where they think it’s fun to rev the engine as loud as they can?

kurthr 7y ago

Exhaled breath is about 3.8% or 38000ppm so (20000) that's really high! I'm not too surprised since the turnover rate through a few small holes with a relatively large volume is bad. Reducing the facial volume would help a lot as each breath would expel more CO2 as a fractional percentage. It seems that any sort of face covering or even significant exercise could raise your ambient CO2 level well above 1000ppm. I'm a bit surprised that levels 38-60x below our exhalation % (and it's not lack of O2, because you use up less than 10%/breath) has such a significant effect. The one thing that may drive it is that the efficiency of lung ab/desorption goes roughly as the square of concentration so a 2% change in CO2 concentration might be enough to have an effect on O2 and blood pH.

Klathmon 7y ago
I found the study I read, and I'll re-link it here, it is eye opening to say the least! https://www.ncbi.nlm.nih.gov/pubmed/15893291 https://www.ncbi.nlm.nih.gov/pubmed/15893291
- kurthr 7y ago
  Really interesting article... all the numbers are completely believable, but seem really high based on the conference room effects at 0.1% They even refer to a person without a helmet in still air as being at 2000ppm, which is comparable to the worst tested "school house" data. I'd argue that if there is an effect here it isn't the O2 concentration since a 1% change in atmospheric pressure happens at about 275ft. That's a pretty small hill! A 1000ppm change in 02 partial pressure happens in about 30C temperature change. Really, if this is a real effect it better be actually due to some effect of C02 concentration.
- inetknght 7y ago
  Is there a link for the Elsevier-disabled people?
  - Vinnl 7y ago
    Unfortunately Unpaywall (tip: install the browser extension!) doesn't find any: https://unpaywall.org/10.1016/j.apergo.2005.01.018 https://unpaywall.org/10.1016/j.apergo.2005.01.018 So unless you're willing to go the illegal route through Sci-Hub, I'm afraid you're out of luck.

burger_moon 7y ago

I wonder what the number is for people who wear respirators for dust/fumes. There's the paper masks people are most familiar with and the charcoal canisters for working with chemicals. Since it's sealed off would it be even higher than a motorcycle helmet?

jdavis703 7y ago
There’s probably all kinds of confounding factors here, but on high pollution days (code purple air quality) when I’m bicycling I need to take my N95 mask off every few minutes for “fresh air.”

jak92 7y ago

> "house fan" for 15 minutes or so every hour at night just to circulate the air in the house, Depending on your climate, this could significantly raise the humidity in your house. Reason is that moisture from the AC coil are wet after the AC turns off. Typically drips off into the pan until next time AC cycles. If you run the fan you will then evaporate into the air circulating some of the moisture just removed.

Klathmon 7y ago
I live in florida, so I'm well accustomed to the humidity! But thanks for the tip, I actually hadn't thought about that. Part of my home automation system is humidity sensors as well, and while they do spike over 65% sometimes (probably when we have the windows open), they stay around 55% to 60% for the past 30 days. Since I'm only running that fan cycle at night, when the AC tends not to run or not run as much, I'm guessing that helps mitigate the effects of that.
- deleted 7y ago
  [deleted]
asdkhadsj 7y ago
Doesn't that heavily depend on the design of the AC system? I know nothing here, so this is heavily a question. I ask because I have a heat pump for cooling/heating, but the furnace is the blower. I thought when the fan ran, it pulled from the outdoor intake which is in a very different location from the actual heat pump coils. Thoughts?
- jak92 7y ago
  The air handler uses inside air only. The compressor heat pump is outside and either runs its cycle strictly on outside air
abfan1127 7y ago
that moisture came from inside the house. When it drips, it usually drains outside the home. Perhaps it just pedantic, but it won't raise humidity, but it may lower less.

castratikron 7y ago

I monitored the CO2 in my bedroom every second for three months and I found results similar to you. If I was sitting right next to the sensor in the evening it would go up to about 1900 ppm. Cracking open the window for an hour or so eventually brought things down to the 500ppm range. What was interesting is how fast the ppm increases when someone enters the room. I would plot the data and see a blip on the graph when I entered. It was within seconds of entering.

colechristensen 7y ago
I noticed the same when I am sitting near the sensor. I'm thinking though that it is partially due to me essentially breathing onto the sensor and the sensor dynamics having an averaging function so that I'm not sure what the sensor reports and what I breathe in are the same. Repositioning the sensor so it wasn't in the "line of sight" of my breath changed the readings significantly.
- castratikron 7y ago
  Here's a plot. The peaks are when I was in my apartment. The gap in the middle of February was when I went on vacation. https://imgur.com/a/HtyhTzo https://imgur.com/a/HtyhTzo
  - JohnJamesRambo 7y ago
    That is really cool. Thanks for sharing, I love it when people collect data.

olivermarks 7y ago

Your post has made me consider getting a C02 monitor, will something as simple as this 20 buck Chinese version suffice? https://www.newegg.com/Product/Product.aspx?Item=9SIADJN8NP4860-9SIADJN8NP4860&gclid=CjwKCAjw_MnmBRAoEiwAPRRWW1Dv2zvRP-y-ajNDezjPEmJ0RMZDDzJpZRj0kpjceEO3CeQm0yIwqRoCW18QAvD_BwE&gclsrc=aw.ds https://www.newegg.com/Product/Product.aspx?Item=9SIADJN8NP4... Seems a useful thing to have. Separately it is very stressful being on stage at conferences that are stuffy with no fresh air, hot stage lights and probably very low oxygen. I had a friend who did press ups before going on stage to energize herself as the tech conference chair and raise the energy level of the sleepy audience - she got really out of breath!

rootusrootus 7y ago
IIRC the thing to be aware of is that a monitor that actually measures CO2 is going to cost several hundred dollars. The cheap ones don't measure CO2, but some kind of VOC as a proxy. So depending on the source of the CO2, they can be more or less accurate. Something to research. I'm not an expert, just someone who recently did some shopping for CO2 monitors for my home.
- olivermarks 7y ago
  Thanks!
- tolmasky 7y ago
  What did you end up buying?
  - rootusrootus 7y ago
    I didn't. Part of my requirements are that I can tie the device into my home automation. After doing a lot of digging and not finding something I wanted, I shelved the idea of adding CO2 sensors to my house for now. Decided instead to just assume CO2 was high, and I'm having a whole-house HRV installed in a few months.
Klathmon 7y ago

irrational 7y ago

How does kissing affect CO2 levels? I know I've done some stupid things after kissing.

bacon_waffle 7y ago
Anecdata, but since I've started wearing SCUBA gear to meetings, I haven't been kissed once. Maybe it's more about high CO2 levels leading to kissing?

laythea 7y ago

"...high CO2 concentrations in the helmet can be really dangerous to an unconscious person's brain function" Yes but no helmet is even worse for an unconscious person's brain function :)

Klathmon 7y ago
Oh absolutely! I hope I'm not coming across as advocating for people to not wear helmets! I just thought it was a very interesting study and that helmet manufacturers could possibly find ways to mitigate it.

xur17 7y ago

> I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over 1000ppm IIRC. Any recommendations on CO2 monitors?

MichaelDickens 7y ago
I don't have any domain knowledge on CO2 monitors, but I use this one: https://smile.amazon.com/gp/product/B01FYWU2IS/ https://smile.amazon.com/gp/product/B01FYWU2IS/ It's a greenhouse CO2 monitor, which is the most common kind. I've heard that they're not as accurate as CO2 monitors that are designed for humans, but those tend to be much more expensive.
rectangletangle 7y ago
I always sleep with the window open, because the fresh air feels nice. In evolutionary terms, you could speculate that the nice feeling of fresh air could be an instinctual response directing the organism to seek higher quality air.
gustavam 7y ago
I did quite a lot of research trying to find the best CO2 sensor that would also do humidity/temperature. CaDi by nuwave* is what I settled on. An Irish company. I've been using it for a week now and it is working great! Things that surprised me: the difference it makes if I leave all the internal doors open in the apartment, not just the bedroom door. That even leaving one window open just a crack will help with ventilation. And of course how quickly a room with couple of people in it can go above 3000ppm CO2. *https://nuwavesensors.com/product/cadi-ci-100/ https://nuwavesensors.com/product/cadi-ci-100/

calvinbhai 7y ago

As a full face helmet proponent and user (since I started riding motorcycles in India), your comment really makes sense. This is something I used to do almost on instinct,usually at lower speeds (because the helmet had a sort of an intake and a vent that worked well at higher speeds).