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.
Sorry, but this is just wrong and is the type of "accepted wisdom" that holds back construction, particularly here in the UK.
Repeat: ventilation and permeability are different things.
Yes, permeability can achieve some ventilation but it comes at the cost of:
1) Not being reliable; it is dependent on pressure deltas around the dwelling.
2) Being potentially deleterious to the fabric of the building where escaping warm air cools and water condenses on surfaces in the fabric.
3) Being wasteful of energy.
The solution is to separate the two:
1) Seal the fabric totally, bearing in mind vapour permeability. The seal should be on the warm side of the insulation.
2) Install a ventilation system which provides reliable fresh air and, ideally, exchanges the heat leaving the building with the fresh air coming in.
We can no longer rely on folksy wisdom. Let's engineer our houses.
Also check out Matt Risinger. They both have various good content on building science.
I recently added A/C cooling to a previously heat-only house, and I took the opportunity to ask the company to explain some quirks in the existing system, like how the ventilation fan in the laundry room is on the same breaker as the central heating, and had a hidden timer attached to it.
The house was built (early 1990s) with a particularly powerful vent fan in the laundry room which was on (regardless of the wall switch) a certain number of hours a day, and the forced-air system had an air intake outside the house which mixed with the return air before hitting the filter.
This was all sized such that all the air in the house would be replaced about once every 24 hours, according to WA state's VIAQ ("Ventilation and Indoor Air Quality") code.
That's all been superseded by the International Mechanical Code and International Residential Code.
The problem is that many retrofits don't bring in outside air into the mix and just recirculate what's already in the house. This is not current best practice.
If there is no draft, it means there is no air circulation.
The only difference is if the draft goes through HVAC vents or through unsealed doors and windows, or through walls.
If your local heaters are effective and seal controllable, there should be really no difference in many municipal settings as the heating is waste heat from electricity generation anyway. (Those cooling towers "greens" love to hate.)
Certain baseline air flow is strictly required and it is quite a lot, especially in small volumes.
Now, if you have to burn something to heat, then by all means do install a heatpipe recovery system.
With the added bonus that the air can be filtered as well, instead of coming in as-in through leakage.
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).
I lived in a house built around 1985 that had one, which was R-2000 , so they're at least that old.
South Africans are (at least historically) quite different in this respect. Everyone is cold in the winter due to complete disregard for insulation (at least, when compared to Europe). People also don't get layering. The comments about construction do hold mostly. In the warmer areas of the country usually you are cold in the winters for only a couple hours per day.
When we go overseas we tend to open all the windows. Maybe this is because we are not used to long winters.
My grandparents were experts at opening select windows in their houses to create drafts in the pre-aircon age.
There is a meme: "If a guy invites you to a braai at his home at 3am, it really is a braai."
Mold is not a ventilation problem, but rather a moisture control problem. Keep the humidity down (especially with whole house dehumidifiers), and eliminate condensation points (by eliminating thermal bridging), and it goes away.
While the above video, which is from the really good channel by Matt Risinger, is a good introduction, I recommend you also check out the building science stuff put out by Joseph Lstiburek for a more science-y explanation:
On the "perfect wall":
Presentation on control layer (especially starting around 15m):
This sounds like one of those kinds of answers that only works with spherical cows in a vacuum.
If my shower were completely open and in the middle of the living room, perhaps. Alas, it's in a small private room that usually has the door closed while in use, and now we've circled back around to ventilation...
There are houses that are almost hermetically sealed, and do not have issues because they control temperature and humidity properly:
Closer to the correct definition shared amongst building scientists is to allow the passage of water vapour. Many engineers would disagree with the approach of having non-breathable walls. If you're renovating old properties you are putting a LOT of faith in your VCL if you go this route.
I like the concept of breathability personally, allied with high air tightness. But you have to use the right materials and, crucially, install it right.
However, if you're doing an air barrier, you can often get a moisture barrier "for free" nowadays. Since a lot of housing uses OSB/plywood, if you go with something like Huber's Zip System--which has a coating on it--you can save a lot on labour by only doing one pass around the house. Though you do have to seal the seems as well.
Otherwise something like the popular Tyvek will get the job generally done, but there are peal-and-sticks as well that tend to be tighter (and vent as well, like Delta Vent).
If one is okay with the cost, there's also the idea of simply closed cell foaming the entire house. :)
My house is absolutely frigid during the winter, and I got quote for resealing it. He told me that afterwards I am either going to have to leave my windows open (no thanks!) or live with mold.
I've heard that you can install vents, but can't find useful info.
My grandparents had a chute vent, and it somehow became a breeding ground for flies and all sorts of ichies. Not sure why.
And short vents sound to me like an always open wondow, which just brings in the cold.
I want the insulation, the circulation, the breathability and the warmth. Is there any way to have it all?
You can also look at whole house dehumidifiers to take the water out of the air to help reduce the mold problem.
Go through the archives as well. Lot's of good stuff.
He's based in Austin, TX, so needs to worry about heat and humidity being kept out, but the principles also apply for colder climate where the cold needs to stay on the outside.
Another good person is Lstiburek, and his concept of the "perfect wall":
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.
I’ve attributed this to “fewer people, fewer distractions.” However, with a CO2 component... hmm.
Well, there is another project idea. Arduino with a CO2 sensor and plotting a running total. Or not displaying and instead have a “I feel productive” dial that would allow for correlation to the recorded data.
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.
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.
CO2 is damaging to your body, I am not an expert in these matters however I know that much.
Becoming tired due to CO2 is in effect a minor form of gassing yourself, and during sleep high CO2 is bad for you and I would assume does not give you high quality sleep - same as alcohol makes can make you drowsy while also interrupting your sleep.
"Natural" sleepiness has none of these downsides.
Most of the claims are trivially verified true with a proper understanding of hypoxia and the effects on the brain.
Of course you want to be sleepy, but you don't want that sleepiness to be due to hypoxia because hypoxia is known to damage the brain.
The link you gave makes me think I actually have to dig through quite a few studies to find something supporting what you said (it's not on the first page, for anyone wondering), which is why I asked for direct sources.
A simple search of "hypoxia from excess CO2" brought up https://en.wikipedia.org/wiki/Hypercapnia, which also support the claims.
Please, for the love of god, learn to google properly: http://www.catb.org/esr/faqs/smart-questions.html
Then this must have been before 2016. Atmospheric CO2 concentration has always been higher than 400 ppm since that year.
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, and using the word "really" is against my own advice, but there are exceptions, here above was one)
“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.”
ImmerseintheImmensity, Also unknown as InfimousInfinity, Also unknown as ParadoxParalax
It can integrate with HomeBridge and has a good API and unlike a lot of IOT stuff it’s well supported and stable.
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).
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://...
The predicted number is much closer to around 650 ppm, and that's assuming no change.
In reality, things like solar technology have massively gone down in price over the last couple decades, and are only continuing to reduce in price.
We will likely see 2-3 degrees of warming, but no credible scientist is making the predictions that you seem to be making.
If there is no change in CO2 emission, then yes we might restrict the total damage to 650 ppm. But "no change in CO2 emission" doesn't mean "business as usual", it means a moratorium on all kinds of expanding industrial activity.
Not only are CO2 levels increasing, but CO2 emission rates are increasing. Hell, the first derivative of CO2 emission rate was also increasing until the past couple of years, a minor but happy development that could easily snap back. "Business as usual" means an exponential curve.
Solar powered industry is still a far-off pipe dream. Even if it only takes 30 years to replace all energy sources with sustainable alternative, in 30 years huge damage will have been done. We cannot afford to just shrug and say the problem will just solve itself.
As predicted by the scientific consensus and the intergovernmental panel on climate change.
Disagreeing with them on this is no different than being a climate change denier, TBH.
The right thing to do is listen to the opinions of the experts, and this is what the experts believe and is the scientific consensus.
Though solar and other non-carbon energy sources are coming down in price, world energy needs are outpacing them. Out CO2 emissions are increasing, not decreasing. I doubt that we'll see 1000 ppm by the turn of the century, but if the "no change" projection is 650 ppm then by simple matter of inference, due to increasing CO2 output, we should be higher than that.
Why? Because if solar power and others, continue to go down in price, as they are doing now, then solar ect will be cheaper than coal.
From a purely economic stand point, countries will eventually just stop burning coal, because the alternatives are just flat out cheaper, even when you ignore the costs of global warming.
That point in time, when alternatives are just straight up cheaper than coal, isn't too far away.
The trouble is that countries are not purely rational, and do not factor in all externalities.
I have a sensor and try to keep readings low. My girlfriend isn't quite convinced though, especially in winter....
Outside is 400 globally but often 450 or more in cities. At least on my meter.
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.
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.
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.
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
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.
Your anecdata has cemented it as fact(tm).
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.
Not a great choice if you ask me.
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.
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.
This makes them very attractive for older renovated building, which used to rely on drafts for air circulation.
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.
: 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.
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 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."
This is a conversation about the levels of CO2 and how it effects a person, especially their sleep. In this part of the conversation people have started to talk about how the temperature also effects your sleep. This was a natural progression, as less CO2 needs more ventilation, and brings with it colder temperatures.
You then started talking about two groups of indigenous people in different climates. Brilliant, I'm interested in how these two groups of people sleep! You however did not talk about these people's sleeping habits (as would have been another natural progression for the conversation) but instead go completely off the topic of conversation and talk about a bunch of unrelated topics, with very tenuous links between them.
Your comment did not add to the conversation, at all. Neither has mine of course, but I hope it goes some way to explaining the unpopularity what you said.
Only see this your comment now, long time after.
But Thank You for taking your time to help me seeing those things, really.
Cheers and wish you all the good in the universe!
Given the cost of the device I would be amazed if it wasn't a VOC based sensor. The cheapest CO2 sensors I've seen are well over $250, even in bulk. CO2 is quite innert, so it requires very precise and accurate components
i live in a drafty pre-war building and my co2 peaks at around 1500-1600 ppm at night with doors and windows closed. it troughs at around 500 during the day when i have the doors and windows open (~400 is ambient from what i understand). tvocs typically peak around 600 ppb and trough at around 20 (under 100 is considered safe iirc), with the same cycle as co2.
By 2100, we may be at 800ppm if we continue and/or accelerate fossil burning (4 degrees C trajectory). https://www.co2.earth/2100-projections
Already a middling stuffy room, and would increase indoor levels 400ppm over today.
“An active person exhales about 1 kg of CO2 per day. So, you would need 1000 square meters of grass to absorb one person's CO2. That's a square about 32 meters on a side, or in archaic units, a quarter acre. A one-square-kilometer park could support 1000 people, just with the grass.“
(Or: Need about 16 trees per person.)
I'm thinking of picking up a plant or two and pointing a fan at the door to send out some of the stale air.
The public labs design uses a aquarium bubbler to push the air, but the flows are pretty low - with retention time in my 10x12 office at 1 month. Since the VOC's are usually heavier than air, if you place the pump inlet on the floor it performs better though.
i got 6 plants (but 1 died) and they make my living space feel more lush and comfortable, which i count as a win.
i did also eventually get a air purifier (blueair 211+) and that’s probably the main workhorse at night with the doors and windows closed (which is when i need it the most). i noticed a clear drop in allergy/asthma symptoms (sneezing, coughing, headaches sometimes) after getting the air purifier.
so a fan at the door will probably have the best bang for the buck for you, but plants are nice too. =)
It measures with an infrared spectroscopy-based sensor, which should be quite accurate. There are a few good software packages for recording data, e.g. https://github.com/vfilimonov/co2meter.
We built that into a custom SS body with a Delrin mounting insert, and ran the serial connections to a custom board that interfaced with up to 8x sensor locations (in conjunction with some other sensor elements). The elements were ~US$200/ea ~4.5 years ago.
These are fancy interpolated IR absorption sensors internally, so any gases of similar concentrations could throw off the readings; depends on the environment. Would be BEST to calibrate to local atmosphere conditions of the installation, but that's not really something you can sell. :P
It would be amazing if you or anyone really could make a comparison between different models - and show whether the cheap ones on amazon and the likes are worth it.
Sort of related, I'm living in a newly constructed house and I'm interested to know the indoor air quality. Any recommendation for a comprehensive in door air quality test solution (either device(s) or hire someone maybe)?
I don't have any sensors to get a real idea of the difference in CO2 it makes, but it allows us to run the furnace less at night (heat from the lights), and makes a noticeable difference in humidity ( very dry air here ).
Also, we get about 1-2 family meals / week of food at full capacity ( total 4x8 grow space and 800 watts of light running only at night ).
Not economical and takes a lot of maintenance, but it's a fun hobby from which we all feel the benefits.
Dear God, what's your power bill? There's no way a LED lights heat is as efficient as just using the furnace.
edit: I meant cheap, not efficient.
If they have a gas furnace it might be different but that would also depend on how their electricity is generated.
According to http://web.archive.org/web/20180822025250/https://portfoliom... heating with grid electricity would require 2-3 times as much primary energy as heating with water/oil/gas.
Now, converting electricity to heat may not be as cheap as converting, say, natural gas to heat (thus making the heat pump un-economical when not pumping any heat)... but you do get heat out of it.
The average is 30 BTU / 1000 sq feet. That's 10 kW / 1,000.
Certainly not an efficient way to heat the house, but the main concern is oxygen and not generating co2 with the furnace, then air filtration (SLC nasty air), then humidity, then food, THEN heating.
edit: we vent the tents directly at our beds
I guess the water heater might cost some money, since it produces heat, but a lot of that heat just goes down the drain with the water.
I have also seen some pretty cool looking "passive" houses that, due to excellent insulation, are able to heat the entire house with a 3kW furnace . And these are in very cold locations (e.g. Alberta, Canada).
Electric heating is the future!
Mitsubishi has some that can extract heat from the outside air even down to -30C.
Most though only work down to about +5C (they're used in more temperate climates). So check the specs.
They also work for AC.
It's possible to design house that need almost zero BTUs:
When looking at bang-for-buck / value / ROI, better insulation and air sealing should be done first. If you can reduce the number of your blower door test, then you'll have to spend less on running capacity (and their related costs).
Gwern.net has useful heading information on each page. This particular one says:
> modified: 13 Dec 2018; status: in progress;
Presumably the status tag will be modified to "draft" or "finished" once conclusions are available. https://www.gwern.net/About#confidence-tags
We researched the latter recently and found out, that this idea was spread after the war so that the children would not eat too much of the freshly baken bread, because it tasted better. No health implications at all.
My parents had limited vocabulary, but in a way they meant the same thing. Stale air (a hopefully faithful translation from my language) can have many meanings, but in context it means air with high CO2 concentration. I'm wondering how much of this is also the disconnect caused by fast technological progress and evolving language with it.
This leaves aside parental scorn/ignorance as you describe it. Sounds like stressed-out parents, if I may say so. However, I don't know how future generations will get better at it, only that you may get better at it.
Of course it varies greatly depending on the person, temperature, state of immune system, humidity, etc.
But it's just the opposite of hot tea helping you cough less.
However I suspect that most people don't sleep on the ground floor (either in a multi-level house, or in an apartment building) so for them this should be less of a concern.
But if you're actually contending with both at the same time, there are window bars that are placed inside the window, not outside.put the blinds between the window and the bars, then crack the window open and get some airflow.
Or hell, install a fan in your attic, the way people used to before AC was ubiquitous. Bedroom ventilation is not an unsolvable problem. If you really want a solution, you can find one. If you want an excuse to have no solution, I'm sure you can find endless excuses too.
There are other solutions as well. Many window frames are designed to permit the window to be cracked open but not opened fully, to prevent ingress while still allowing egress (either by disengaging the mechanism or by breaking the window if necessary.) Such a mechanism can often be retrofitted to an existing window frame for no more than a few dollars. I've seen people create their own using a short length of dowel rod placed such that it prevents the window from opening fully. There are also a variety of purpose made mechanisms on the market.
These mechanisms are not as secure as bars on windows, but about as secure as a normally closed and locked window. The payoff for less security is enhanced aesthetics and fire safety.
There are many reasonable solutions to bedroom ventilation.
Even though there are cognitive effects of CO2, most often the CO2 levels in indoor rooms are simply a sign of low oxygen levels. In fact, there should be an inverse relationship between CO2 and oxygen in rooms. So an experiments would need to take this into account and supply pure oxygen to make up for the oxygen that has been used up.
It should therefore be pretty easy for CO2 researchers to control the outcomes of their experiments against the known physiological effects of hypoxia, to determine what effects are actually caused by CO2.
And aside from that, the dosages being discussed here are far, far lower than would be a noticeable dent in the amount of oxygen in the atmosphere. 1000 ppm CO2, the lower bound of observed cognitive effects, is 0.1% CO2, way less than the point where hypoxia is known to cause problems. The atmosphere is 20.9% oxygen at sea level and while I am not an expert in the math of partial pressure, a decrease of atmospheric oxygen to 20.8% doesn't strike me as sufficient to explain the observed effects. That's a 0.4% decrease in the partial pressure of oxygen, or about the equivalent of a 300 foot increase in altitude, or taking an elevator to the 20th floor of a building, nowhere near enough increase in altitude to make you light-headed.
In a closed small room, the oxygen is mostly used up after a couple of days.
One person in a small tightly closed room will lower the oxygen level significantly, by 5-10% (consumption is around 20 cubic feet, and a small room has about 200 cubic feet oxygen in volume in total)
CO2 and oxygen work in tandem in the human body, and studies in the medical field have shown that an increase in carbon dioxide increases breathing rate, breathing volume, heart rate and metabolic rate.
The result is an increased need for oxygen, which will not be met in a closed room.
Thus I speculate that an increase in CO2 with an accompanying increase in oxygen (or at least a stable flow) will mostly negate the observed symptoms.
My preliminary working theory would be that the previously observed effects from high CO2 in rooms (office rooms for example) are due to the interaction of both high CO2 and low O2.
The amount of oxygen used is way higher.
A person consumes 19 cubic feet of oxygen a day.
Edit: I looked at the composition of inhaled and exhaled air, and now I realize the reason O2 is being taken out of the air in higher amounts than CO2 is introduced, is that the exhaled amount of carbon dioxide is not the total amount of carbon dioxide that has been created in the body.
When the CO2 in the room gets higher, more CO2 is actually taken up again from the room back into the human body, with the exhale rate staying relatively constant. Or in other words, a significant part of the increase in CO2 in the system human <-> room is actually in the human, not in the room. The room measurement thus covers only a part of the CO2 being produced in total, and only the unknown total amount of CO2 produced reflects the totality of O2 being used up.
This means a change of 1000 ppm of CO2 in the air will mean a higher amount of oxygen has been used up.
This could potentially account for why no ill effects of high co2 were found in submarines. Presumably o2 supply there is well maintained.
Do household air quality standards include o2 levels?
The comment about submarines is highly interesting to me, I will look into the studies! If you have any sources about that to share, I would love to read them.
Every time you breathe in, you not only breath in O2, but also CO2, thus lowering the amount of CO2 in the room relatively to the amount of oxygen.
In other words, 1000 ppm CO2 in the air do not mean 1000 ppm O2 less, but significantly more parts of oxygen less.
... not at all. No CO2 is "stored", though it may temporarily hang out in buffers such as the blood. But they have a very limited capacity and the flow out is extremely close to the production on a very very short timescale, and on a longer timescale approaches equality.
> which means a higher amount of oxygen is taken out of the air, then CO2 being reintroduced to it.
This is true, and I was wrong in my comment, but not for that reason. Only some of the O2 used is paired with CO2 and breathed out. Some joins with hydrogen from foods and becomes water. Most foods are carbon chains, with each carbon atom having two hydrogen atoms, so this ratio can get as high as around 2:1 for low-oxygen foods like fat, but lower for carbs, which tend to have significant quantities of oxygen (which will in balance add to the O2, meaning that more of what is used up when breathed in is breathed out). (Proteins also have nitrogen which complicates things.)
(Meaning we could rule it out as an explanation for the effects, if the effects do exist)
Now I'm curious how effective they are at keeping down CO2 levels at night. I would like to try this experiment in my house.
We've had new UPVC windows installed over the past few years and they've all got hidden 'trickle' vents.
1. Abundance of flimsy anecdotal evidence
2. Mostly subjective measures of outcome (I feel smarter and refreshed!)
3. Seemingly plausible, but totally unverified scientific reasoning
I'm not holding my breath yet.
I've noticed that sometimes after spending extended periods of time (in the magnitude of hours) in very close proximity with a significant other (e.g. cuddling, kissing, etc.), I feel groggy, dizzy, and have brain fog/difficulty focusing.
Could this be related to CO2 levels? I've been feeling it today and was wondering if it is hormone related, but CO2 could be an interesting explanation as well - I have noticed my breathing tends to slow down during these times as well.
I've never heard anyone else describe this so if you have any similar experiences, please share so I don't feel so alone with this.
What are your thoughts on seeing an endocrinologist about this? In addition to oxytocin, testosterone, etc., I was also wondering if it might be related to prolactin levels.
I also just read some people talk about similar symptoms here but no clear answers: https://patient.info/forums/discuss/partner-becomes-ill-afte...
It quickly confirmed that, without turning my thermostat fan to "ON", my bedroom CO2 jumps from about 1000 ppm to 2000 ppm within a couple hours of us going to sleep.
In the fall, my wife and I started waking up in the middle of the night feeling like we couldn't breathe. What I figured out is that the neither the heat nor cooling was running because the weather was pretty much perfect. We have to keep the door closed because our cat will swat at us in the middle of the night otherwise. I figured there would naturally be enough of a draft to not make this a concern and it's a fairly large connected master bedroom/bathroom with high ceilings to hold a lot of air, but I guess that isn't enough. So that's when I learned about the "fan" function on my thermostat.... never had a need for it in my life.
Now I just need to figure out how to get lower than 1000 ppm, which is already a hit against cognitive function. Our house has no screens currently and even if we install some, it's not like I want to have windows open in the middle of winter. I've heard house plants don't have a huge effect, but I'm willing to try.
My kids may well see stuffy room CO2 levels outside within their lifetimes.
>back-of-an-envelope calculations suggest you’d need around 400 houseplant-sized plants.
I have 18L of Spirulina, which appears to be having some effect, though not anywhere near a complete offset. Though, my setup is quite sub-optimal, and I've seen articles that suggest Chlorella is a couple times more efficient at biofixation than Spirulina. Continuing to tinker :)
In the talk I linked, DHH said he had tried dozens of other sensors and found this one surprisingly accurate for the price point. He did mention the temperature and humidity readings were not as accurate as he expected since sensors for those are so cheap, but that's not really why I got one.
We started running it like that only at night as we found that the bedroom would get pretty warm during the summer while the center of the house (where the thermostat was) would stay nice and cool, but after running it like that for a bit, decided to just let that routine run all 24 hours of the day since it equalizes temperatures so well across the whole house.
Though all this time, I thought it was just the heat. I wonder if the CO2 levels are also what is keeping me waking up at 4-5am every day...
I'm going to try this circulation trick with my Nest now and see how it goes.
At first I was worried about the extra electricity usage or the extra wear and tear on the HVAC system, but after trying it at the recommendation of a neighbor, I've been nothing but happy, and I haven't noticed any change in my electricity bill so there's no worries there.
After reading this, I got a Netatmo CO2 monitor like Scott and Gwern. I found that CO2 peaked in my bedroom at around 1500 PPM at 6 AM with the door closed and that I could keep it under 500 PPM with the door open or a window open.
Scott Alexander also suggests getting around 10 succulents, if you don't want to open a door or a window.
Edit: Scott Alexander also published these survey results from other people who experimented with reducing CO2 in their homes: https://slatestarcodex.com/2018/10/04/nighttime-ventilation-...
Why not move the weather station to the bedroom for a couple of nights? (And make sure the sensor is at nose/mouth height, preferably close to it. CO2 is heavier than air, so concentrations may be higher closer to the floor in a closed room with little movement)
I would also do a back-of-the-envelope computation along the lines of https://www.globe.gov/explore-science/scientists-blog/archiv... or https://ac.els-cdn.com/S1877705813007558/1-s2.0-S18777058130..., to verify the numbers the weather station produces.
And the lesson of all this seems to be: get a large bedroom and leave the door open (both easier for the well-off, so get rich parents!)
How significant is the gradient? Would it make a noticeable exposure difference to sleep in a high bed versus a mattress on the floor?
which he did, not too far further into the article?
EDIT: it appears the Livpi uses a K30 chip. The K33  is the version sold on industrial sites.
That said, seems there are some succulents that do most of their co2 intake at night. Those would work best for co2. But you would need....at least 30-40 of them.
Opening a window, by contrast, works extremely well, and quickly. However, this requires non-polluted outside air. Else you're exchanging lower co2 for pollutants.
I can't remember the total, but I recall seeing a calculation about this and it didn't amount to very much energy, especially if the bedroom heat isn't on super high.
Anecdotal, but I've heard the Germans often tend to keep a window open a bit year round, and I know my grandma did even in winter. She was pretty frugal too.