12 ms·
I was lucky to get my hands on 5 proper co2 sensors from university, while I was teaching and working. So plenty of test places. What I found: -Just a couple
by DocG 8y ago
I was lucky to get my hands on 5 proper co2 sensors from university, while I was teaching and working. So plenty of test places.
What I found:
-Just a couple of hours in a office, without ventilation spikes the co2 enough to make everyone dizzy and tired by the end of the day. Keeping eye on the meter and ventilating properly, increased everyones productivity and people werent so tired by the end of the day.
- Classrooms, with 20-30 people are as bad. co2 rises really fast and makes people dizzy. Most often ventilation is too low, as a cost saving measure.
-Closing bedroom door, sleeping alone made bedroom as bad by the morning than classroom or office.
-Main culprit seems to be our perfection with insulating and making rooms airtight. I do live in a cold climate, so having open vents or windows is not common half the year. It seems it has not been such a big issue before plastic windows or in older houses. I think it is getting worse with every new building.
- deleted 8y ago[deleted]
- kickout 8y agoCurious if you have a link to what sensors you had? Think this is cool and i've been on/off looking for co2/o2 sensors greater than recreational precision
- leonroy 8y agoCan’t speak for OP but I’ve been using the IQAir Air Visual Pro and can support everything they’ve said. I try to keep CO2 around 400-500 in my office and home but it spikes surprisingly fast with even one person breathing in a medium sized room. It can integrate with HomeBridge and has a good API and unlike a lot of IOT stuff it’s well supported and stable.
- forthispurpose 8y agodo you know how accurate it is?
- benmccann 8y agoIt seems pretty accurate. The South Coast Air Quality Management District tested a bunch of consumer devices against a $30,000 professional device. I was deciding between the IQAir and Laser Egg 2+, which both did well according to their tests http://www.aqmd.gov/aq-spec/evaluations/field http://www.aqmd.gov/aq-spec/evaluations/field. I got the Laser Egg 2+ the other day. It's really enlightening to see how it spikes when we cook dinner or lunch on the gas stove.
- drited 8y agoDoes the Laser Egg 2+ monitor CO2? Looking at the kaiterra product page [1] I don't see it [1] https://kaiterra.com/compare-page/ https://kaiterra.com/compare-page/
- leonroy 8y agoPretty accurate, there was an air quality report which compared about 3-4 samples of them with commercial air monitors - the lab found them adequate with some but not massive sample variance. They were the best of the consumer models tested. Can’t seem to find the report but to be honest I stumbled on it while searching for PDFs on the subject a year or two back. (I own no stock nor have any affiliation with IQAir - just a satisfied customer - high price not withstanding).
- DocG 8y agoThey were too expencive to buy recreationally, at least for me. Evikon, small company that does science instruments. Sorry, cant find the model anymore, I think it was discontinued. I do belive now though that even having recreational level sensor will give you at least understanding overall co2 levels and this something we should look into more. I founs a paper using the same sensors that measured co2 in schools. In all cases, at certain times the measurement was higher than norm. occassionally over 2000. I can now understand much better kids getting sleepy and unable to concentrate in classroom. Paper sadly in Estonian only: https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.mycology.ee/wp-content/uploads/2017/10/Kokkuv%25C3%25B5te-_kodulehele.pdf&ved=2ahUKEwju-YC05P_fAhXGiiwKHQWfDp4QFjASegQIBhAB&usg=AOvVaw2WIVlRflGG0GgYqRkUtTBO https://www.google.com/url?sa=t&source=web&rct=j&url=http://...
- gsich 8y agoTry MH-Z14 or Z19.
- Ductapemaster 8y agoFor a couple hundred bucks you can get a highly accurate CO2 sensor that reads out via a USB-serial connection: https://www.co2meter.com/products/k-30-co2-sensor-module https://www.co2meter.com/products/k-30-co2-sensor-module
- graeme 8y agoWhat level was it at when you started noticing those effects? And how did you measure productivity? I have a sensor and try to keep readings low. My girlfriend isn't quite convinced though, especially in winter....
- DocG 8y agoAround over 2000 I think. Less than 1000 would be ideal, I think outside is around 400.
- graeme 8y agoYeah it never gets above 1300 at our place with windows closed. With a window open a crack it stays at 700-1000. Outside is 400 globally but often 450 or more in cities. At least on my meter.
- pkaye 8y agoAir tight buildings need a heat recovery ventilator.
- AstralStorm 8y agoAny ventilator. Heat recovery is optional - it is really hard to recover heat from lukewarm air without actually recirculating most of it. The pressure drop requires more electricity due to more power in the pumps, making it a relatively bad trade - only heatpipe systems are worth anything.
- gnat 8y ago+1 here. I worked at an IoT startup with a lot of gas sensors. When we tested the CO2 sensor, we immediately noticed a correlation between early-afternoon sleepiness and high CO2 levels. Opening the door to the outside world lowered levels and within 5 minutes we felt more awake. It changed how I work: I still like to be warm and cozy, but now I'll bundle up and endure changing the air rather than seal every door and window as I used to.
- John_KZ 8y agoI feel like most of these experiments don't control for air temperature. I feel like cold air has a much more rejuvenating effect than just lowering CO2 levels. Not that they don't matter, but it's not like you'll instantly feel better.
- jodrellblank 8y agoWhy won't you "instantly" feel better? Instant meaning a few breaths of outside air, anyway, likely well within the claimed 5 minutes.
- paradoxparalax 8y agoThere was an NBA coach who use to obligate his players to sleep with at list some inches/centimeters of air access in their windows hotel rooms the night before playing an important game/match. Don't remember what Team.
- Symmetry 8y agoColder temperatures also generally help people sleep.
- xeromal 8y agoI'm pretty sure I read 68F is the ideal sleeping temp
- paradoxparalax 8y agoThat depends if are an an Ianomami[1] born in Brazil or an Inuit[2] born in Denmark. 1- https://en.wikipedia.org/wiki/Yanomami https://en.wikipedia.org/wiki/Yanomami 2- https://en.wikipedia.org/wiki/Inuit https://en.wikipedia.org/wiki/Inuit : There is a risk, not for the Ianomami that are somewhat numerous, but that some other in Brazil are going to Extinction soon, after the last elections in that country. Only if they could move to Denmark...Or Northern Canada, where there are Inuits too. But North Canada recently is so full of political "moon landing" deniers that they probably would not be very welcome there. But Greenland is far enough from "civilezed" people. But they will have to learn how to hunt monkeys and collect mango fruits in the north-pole.
- paradoxparalax 8y agoDon't know if above is getting downvoted by the the rightists or by the leftists here, what is fun. But probably getting d.v. because of being too caustic, too snarky and too ironic, what is not fun and I confess I deserve. And, most important off all, I am getting downvoted for being Not polite to xeromal, and I apologise to xeromal for this. My comment sounded like he was being discriminative or something like that, what is not true, and off course I should have found a decent way of pointing that the ideal temperature to sleep varies from person to person. And off course, I should have avoided going astromically off-topic. But will not delete the comment, to let the lesson there for myself. Irony is really not welcome, I have to make an effort to understand that and abide by rules and follow the recommendations. But giving or asking explanations for up or down votes is equally Not recommended and not welcome, sure. Better to abide. Otherwise just do[1] like Bender Bending Rodriguez of Futurama. The original quote from Bender is: "I will make my own Lunar(really on the moon) Amusement Park, whith Blackjack,... and Hookers!!!. ...Well...forget about the Blackjack...You know what?...forget about the Park too." 1- https://i.kym-cdn.com/photos/images/original/000/348/790/b3f.jpg https://i.kym-cdn.com/photos/images/original/000/348/790/b3f...
- deleted 8y ago[deleted]
- JauntyHatAngle 8y agoMy friend studied Interior Architectural Design, one of his professors there started one lecture a year by getting the CO2 sensors, placing them around the lecture hall, showing the readings at the start of the lecture, closing the doors and then after the hour long lecture showing the readings. During the lecture he mentioned the figures for CO2 concentration that led to symptoms, e.g. dizziness, sleepiness etc. The reading at the end of the lecture showed that it was over the recommended limit, and well beyond the threshold that causes people to get sleepy and lose concentration. (I believe it was less than 400ppm at the start and thousands ppm afterwards?) A simple demonstration using an older building crammed full of students in a closed space, but it was apparently quite impactful in showing the students how there are a lot of features of interior design architecture that aren't really addressed and are only coming to the fore recently.
- nloladze 8y ago>there are a lot of features of interior design architecture that aren't really addressed Nearly every standard rectangular building should be in actuality built with the energy efficient building design in mind, but we don't... out of simple mental oversight and in the increased cost in construction. https://kammaliyaa.files.wordpress.com/2013/01/figure-11.jpg https://kammaliyaa.files.wordpress.com/2013/01/figure-11.jpg Literally, we could save 20% to 30% in energy costs with every building with possibly only 10% to 15% increase in cost of construction, but we simply don't because we have no congregate valuation of resource consumption, only individual guilt.
- vagab0nd 8y agoThis might be a really stupid question but, wouldn't you _want_ sleepiness when you, I don't know, try to sleep?
- justinator 8y agoFollowup rhetorical question: Do you like waking up sleepy and dizzy?
- nine_k 8y ago
- AngryData 8y agoAs someone who has built my fair share of houses and worked on many more over the last 25 years, I have to agree that our ability to seal air better than ever is causing problems, especially if you don't have forced air heating and cooling running all the time. People just completely ignore or haven't ever thought about room ventilation, positive or negative room pressures, and where and how to ventilate to the outside. In older houses there was always air leaks, small, but they let the house breath, especially if you had a central fireplace and your house was at negative pressure. I have seen many people purposefully over seal their house in ill conceived ways, to try and improve insulation, but end up causing ventilation problems with mold being especially common. Materials and vents that should let air pass through are commonly replaced with impermeable plastics and sealing tapes, many times in conjunction with a misunderstanding in expansion and contraction joints that have small gaps.
- marricks 8y agoAnd I recently remember hearing forced air is bad for air quality inside! Did I hear wrong or is there something more to the story like “forced air brings in outside air, so if your outside air is bad you’ll have trouble”?
- Kadin 8y agoMost residential forced-air systems don't bring in air from outside (intentionally at least). They recirculate the air in the building through the heating/cooling unit (typically a combination updraft furnace with AC evaporator sitting on top). Modern systems (since late 80s, maybe?) have return air ducts so that you get even heating even if interior doors (e.g. bedroom doors) are closed, but older systems may only have one return vent per floor or even just a single one in the house, and depend on gaps under doors and such for return air circulation. Bigger commercial forced-air systems have had exterior air intakes and heat exchanger systems for a while, but are pretty new for residential (I've never seen one in the wild myself).
- gregmac 8y agoHeat recovery ventilators [1] are reasonably common in Canada. Most (all?) EnergyStar homes [2] have one, and they includes most if not all the houses I've looked at (or friends have bought) in the past decade or so. I lived in a house built around 1985 that had one, which was R-2000 [3], so they're at least that old. [1] https://en.m.wikipedia.org/wiki/Heat_recovery_ventilation https://en.m.wikipedia.org/wiki/Heat_recovery_ventilation [2] https://www.nrcan.gc.ca/energy/efficiency/housing/new-homes/5057 https://www.nrcan.gc.ca/energy/efficiency/housing/new-homes/... [3] https://www.nrcan.gc.ca/energy/efficiency/homes/20575 https://www.nrcan.gc.ca/energy/efficiency/homes/20575
- scottdupoy 8y agoAre atmospheric CO2 levels rising to an extent that currently projected levels would have a noticeable effect in the same way?
- dTal 8y agoWe're on track to reach 1000ppm by the end of the century, if levels continue to rise at their present (accelerating) rate. This is about the threshold where cognitive effects become reliably detectable. However, such levels also bring climate change on such an apocalyptic scale (4.5+ degree temperature rise) that industrial activity could well wind down as society collapses.
- chronic739 8y ago> We're on track to reach 1000ppm by the end of the century Probably won't be in my lifetime. Not my problem.
- pizza 8y agoProbably still going to be your family's problem..
- muro 8y agoNot with that attitude :)
- deleted 8y ago[deleted]
- dwaltrip 8y agoThat's an attitude that we can all apsire to.
- dTal 8y agoWhy was it so important to you to say something so perversely selfish that you felt compelled to make a throwaway account to do so?
- gamma-male 8y agoWow. Didn't realize how important it was to aerate. I seldom open the windows at my place. I also remember often getting really dizzy working in my previous office, and I couldn't understand why, maybe you're on to something. Now I'm wondering how all of that has affected my health along the years
- KozmoNau7 8y agoThe recommendation here in Denmark is to air out for ~10 minutes, 3 times a day, ideally with all doors and windows open, making sure to get good airflow between rooms. I think very few people actually air out that much, but I've found that it's very helpful for my sleep quality to air out just before I go to bed. Airing out in the morning also helps eliminate moisture from showering, as my bathroom doesn't have a window, nor any forced ventilation.
- simonebrunozzi 8y agoCan you suggest a commercial CO2 sensor that you think is accurate enough? Most of the ones available on Amazon.com seem to be quite amateurish.
- simpsond 8y agoVaisala makes good probes, acceptable for use in life science applications. They are expensive and you need an rs485 adapter for the ones I used. The serial protocol is nice and simple though.
- jodrellblank 8y agoThis is one of my regular arguments in the office, I open a window, someone says "aren't you cold??" and I say "I don't want it colder, I want it fresher, less stuffy". Your anecdata has cemented it as fact(tm).
- userbinator 8y agoIt seems it has not been such a big issue before plastic windows or in older houses. I think it is getting worse with every new building. That's because the focus on energy efficiency means installing HVAC that recirculates and setting the recirculation ratio to as high as they can get away with. Before that, buildings were taking in 100% outside air to heat/cool, which was extremely inefficient but also gave no chance for CO2 to build up.
- Kadin 8y ago> buildings were taking in 100% outside air to heat/cool This hasn't been true since fireplaces stopped being used for heating. Even very basic furnaces, such as the coal-fired one my grandparents had in the 1940s, recirculated the air inside the house. (It was an unforced / gravity "octopus furnace", fired with soft coal, with the house temperature controlled via a damper on the chimney.) But it took its combustion air from inside, and was vented via a chimney to the outside, so the house was constantly at a very small negative pressure, and combined with the natural draftiness of prewar construction there was naturally some fresh air intake. But certainly not 100%! I think it's the newer high-efficiency furnaces where you start to have very high recirculation ratios and consequent CO2 issues. Because they pull combustion air from outside, there's no incidental exhausting of interior air to outside (which would tend to pull in outside air through gaps in the building envelope). Great for efficiency, though.
- deleted 8y ago[deleted]
- pojzon 8y agoWhat i found is that i can open a window to bring fresh air in but togather with it magnitude of pollution that causes cancer and asthma... Not a great choice if you ask me.
- paradoxparalax 8y agoMove out of Beijing right now. Or out of Hebei province, or faraway from North Henan Province. Just move as sson as possible to a place with good air. It does't not worth the money to live in Beijing, no matter how rich you can get there, and you can get rich there, but it simply does not worth. Your life is more important, specially if you have kids.
- pojzon 8y agoI live in Poland and we are the lungs of Europe, still air is polluted as hell.. i dont wanna think how bad it is in other countries. And its not so easy to move out if you dont have enough of money.
- paradoxparalax 8y agoYes, you are right. Not easy. But I am happy to know that Poland's air still can breath, at least, compared to India or China. I have been in Szczecin city once, and I love Poland, and I specially love the Polish people. Wish all good for you guys over there, and that the air gets better in the future, we need to hope.
- codetrotter 8y agoMy previous employer had excellent air quality and I often stated this to others as one of the things I liked about working there. A lot of people look at you kind of funny if you say that but it really was remarkable, and I really felt a difference when working in that building compared to when I went to school and a lot of other places where you stay inside for a prolonged time. I felt much less tired there than most other places!
- a_lieb 8y agoThis is wildly conjectural, but assuming the "CO2 is causing widespread cognitive problems" hypothesis is true, I wonder if there are whole colleges whose student bodies are getting slightly worse grades because of this. There are a couple of small colleges in my area that are regionally famous for their stuffy buildings.
- jodrellblank 8y agoI wonder similar about office buildings or apartments which are next to large car-parks, does that measurably affect air quality inside?
- kijin 8y agoIf most of the cars in the car park are turned off, it might not be any worse than a building next to a busy highway where cars are actively spewing CO2.
- paradoxparalax 8y agoThe worst would be a small leak of CO (not CO2) , even in very small quantities, daily miligrams of CO coming from a leaky(small leak) Gas burning heating system. This will most probably get students scores down, among other extremmely bad health effects. Bigger CO leaks are extremely dangerous, many people lost their lives because of heating systems. If you can, change to Oil Flow system with burner outside the house and far and aislated from humans. Or, if you can, electrical system. CO from gas is Really Very dangerous. (using the word "very" is against Mark Twain's advice[1], and using the word "really" is against my own advice, but there are exceptions, here above was one) 1: “Substitute "damn" every time you're inclined to write "very" ; your editor will delete it and the writing will be just as it should be.” Mark Twain 2- "delete all instances of "really" in you text, and your writing will be better" ImmerseintheImmensity, Also unknown as InfimousInfinity, Also unknown as ParadoxParalax
- general8bitso 8y agoCheck out ERVs, energy recovery ventilators.
- graeme 8y agoThese require a ducting system, correct?
- kilotaras 8y agoNot necessarily. There're units that are installed in, basically, hole in the wall. This makes them very attractive for older renovated building, which used to rely on drafts for air circulation.
- general8bitso 8y agoThere was a link in the comments on this site awhile back from a company that made on similar to an AC window unit, and it had an optional active HEPA filter add-on, whick looked similair to a portable ducted AC. Also, Panasonic makes a bathroom fan ERV for about $400, which you can find on Amazon, with two ducts, one for fresh air intake, and the other to vent the stale air, and you need to have the intake and exhaust ideally on opposite sides of the structure. Some people use it for their basement humidity levels. It is much less expensive to run than a dehumidifier.
- dzhiurgis 8y agoHow are these different from HRV - Heat recovery ventilation?
- nkurz 8y agoHRV's exchange only heat. ERV's (where E stands for energy or enthalpy) also exchange moisture. One is not strictly bette than the other, it depends on your house and your climate: https://www.greenbuildingadvisor.com/article/hrv-or-erv https://www.greenbuildingadvisor.com/article/hrv-or-erv
- deleted 8y ago
- rb666 8y agoAll/most modern houses (10-15 years old) have central ventilation systems here. This allows for great insulation while also having great ventilation. The central system sucks out warm air from bathroom/kitchen and uses it to warm up incoming air from the outside.
- dzhiurgis 8y ago> I think it is getting worse with every new building. Only if you skimp on HRV system (which are cheap and works like magic). It's lame to say it's getting worse, when it's actually getting better.
- Tharkun 8y agoI've certainly worked in poorly ventilated offices, and my bedroom is even worse. But I don't think I've ever gotten dizzy in an office. Is this something that affect different people at different rates?
- chaosbutters 8y agodo you have recommendations for CO2 sensors?