On Habré often publish articles about self-organization - we all want to prokrasinirovat less, and do more useful. But what if the wildest tiredness interferes with doing good things? No task organization will take away fatigue.

It would seem that the work of IT workers is simple - we don’t unload wagons, we don’t dig up the earth and physically should not. However, the wildest fatigue of people engaged in intellectual work must be heard more often than we would like. After I arrived in Moscow 3 years ago - for some reason I began to get tired of the wildest in a perfectly level place, and neither I nor the doctors could find a reason. After 2 years of searching, a trivial and easily correctable reason was found, and in my opinion, practically all people engaged in intellectual work are at risk. The situation is exacerbated by two folk customs.

So, if you have one of the following symptoms (arranged in order of aggravation of the situation) - I ask under the cat. As noticed in the comments - this list has a self-suggestion, so do not give in :-)
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1) In summer, everything is OK, and in winter - apathy, I do not want to do anything. They like to call it seasonal "depression."
2) In the morning everything is OK, and in the evening at work - the brains “do not boil”, I don’t want to do anything — just Habr and reddit to flip through. Come home - and with the wildest fatigue you fall into a chair. Only enough power to climb on the Internet until the night. This point concerns employers , there is a chance that people stop working in the evening not because of their laziness.
3) Even if you wake up without an alarm clock - you do not get enough sleep.
4) Coffee and other stimulants - do not give vigor, just make you angrier.
5) Even if you sleep “as much as you like” - dreams are short and not memorable, or there are none at all.
6) You notice that even 1 thing is sometimes difficult for you to keep in your head. We can forget what you just wanted to do.
7) You wake up already with the wildest fatigue
8) It seems to you that the room is dark and everything is somewhat abrupt.

_Possible_ reason for all this is carbon dioxide (not carbon monoxide!) Gas poisoning.

I deliberately use the word “poisoning”, contrary to the well-established notion that carbon dioxide is considered harmless and harmless. Carbon dioxide is released in the process of metabolism, partially binds to hemoglobin, partially dissolved in the blood - and is removed with respiration. Moreover, the process of "inhalation" is triggered by an increase in the concentration of carbon dioxide in the blood. But the more carbon dioxide in the air, the more it will remain in the blood => the greater the average acidity of the blood (respiratory acidosis ). And when you change the acidity of the blood - absolutely all the processes in the body go awry. One of the consequences is that there are pronounced symptoms of oxygen starvation, despite the fact that the oxygen concentration in the air does not change very much, although it is not possible to find out exactly how that happens. In the plate of symptoms - the lower - the more pronounced the symptoms of oxygen starvation.

It is clear that everyone knows that a person needs fresh air, and you need to regularly ventilate the apartment. But how often? Clear and reasonable numbers, I still have not seen. Now they will appear.

Permissible levels and dynamics of the process

At the end of the 80s, on average, 350ppm of carbon dioxide (ppm = part per million, 0.03%) was in the air, now it is already an average of 400ppm. The person is absolutely perfect at levels of CO ₂ 700ppm and below. At 1000ppm level - if you go into the room with a fresh head - there will already be a feeling of stale air, it becomes a bit stuffy. With growth up to 2500ppm, it becomes more and more stuffy (despite the fact that the oxygen level changes slightly, from 20% drops to about 19.75%), and then it increases with the onset of the above-mentioned oxygen starvation symptoms. Those. when you think that you are stuffy and not enough oxygen - in fact, just too much carbon dioxide.

A person indoors produces approximately 35.2 grams of CO ₂ per hour, and accordingly, if a room is 20 m2 high and 2.5 meters high, then without good ventilation every hour the concentration of carbon dioxide will increase by 584ppm every hour . But since the changes occur very slowly - the person gets used to them, and can easily not notice - just as they do not notice carbon monoxide poisoning (although this is faster).

About folk habits

In the Soviet Union it was fashionable for the winter to stick windows with paper - “so as not to blow.” However, if it does not blow, then where will the produced carbon dioxide go? It will accumulate, which leads to the fact that in the winter people suffer from carbon dioxide. This is especially true of children - “not to catch a cold”. Carbon dioxide is just as dangerous for children as it is for adults and inevitably complicates their studies. Better at home to dress warmer.

The second habit - "included air conditioning - close the windows." Cold air! = Fresh. The air cooled on a hot day to 18C does not solve the problem of carbon dioxide, the ventilation with the same speed is needed anyway - and the whole new air flow will have to be cooled.

Quantitative measurement of carbon dioxide

Until recently, it was very expensive, but now relatively cheap CO ₂ K-30 level sensors based on non- dispersive infrared spectroscopy have appeared , and finished devices based on them, for example MIC 98128 and others (searched according to the CO ₂ monitor, price of the order $ 150): Also about this sensor there is more on Habré .



Measurements showed that in a room 20m ² with one person alone - the level from 400 to 1500ppm grows in 3 hours, and with two people - respectively in 1.5 hours. This means that neither 1 nor 2 airings per day solves the carbon dioxide problem.

I also measured the level in the city and in the metro: in general, everything turned out better than I thought, on the street next to the road I did not see above 500ppm, on the metro in crossings and in “Soviet” metro cars - no higher than 1000ppm, including and in large transitions during rush hour, i.e. ventilation is quite adequate. But in the new cars with air conditioners on the ring line - because of the principle “the air conditioner is working - close the window” - 2500ppm and higher, therefore the air is cold there, but “heavy” and stuffy.

The CO ₂ level in the city should also be monitored by the Moscow Monitoring , but the only station with a CO ₂ sensor does not work for them.

What to do

Someone could have thought of an oxygen concentrator, which I bought all the same (mostly, of course, for experiments). As it turned out, the oxygen concentrator separates not only nitrogen with argon, but also carbon dioxide - according to the results of measurements at the outlet, together with oxygen, only 45ppm CO ₂ . But in any case, a person without fatal diseases does not need a greater concentration of oxygen in the air, so you should not buy a hub.



Maybe you need more time to spend outdoors? Unfortunately, this also cannot radically solve the problem. If you spend 70% of the time in a room with a high level of carbon dioxide, and 30% in the open air, then you will get 70% of the harmful effects (dissolved carbon dioxide in the blood very quickly follows the level of carbon dioxide in the air, nurturing will not work). + -5% solve nothing here.

And need - banal constant ventilation. In the summer, an open-air window or a balcony will always roll, in the winter, either continue to keep the window open and dress warmer, or buy a ventilation system that will heat the air. It may also be the correct exhaust ventilation system. Electricity can be saved using heat recovery ventilation - but such systems are still relatively rare and expensive for “non-industrial” applications.

This also applies to offices: if this is a converted office space without properly functioning ventilation, then problems are guaranteed. This is especially true of small talks in which 20 people are packed. If 20 people sit in a negotiation of 20 squares, then in an hour the concentration of carbon dioxide will increase to 10'000 ppm - and this is the level at which the brains stop working.

There is no need to count on the sanitary epidemiological station - they are not only taking measurements not on the evening peak of carbon dioxide (it’s just before everyone’s going home), it’s also the maximum allowable concentration of carbon dioxide in Russia - ~ 13,790 ppm, fatally a lot.

How the problem was discovered

As it turned out, it was useless to go to the doctors with these symptoms, no one “guessed right”. With my girlfriend, a doctor, we tortured me with analysis for a long time, and cut off all possible causes. The cunning was that as long as you go for analyzes, you breathe in fresh air, and the primary signs are erased, only the consequences remain. One of the tests as one of the reasons (along with cancer) pointed to acidosis. Well, then everything is simple - we find a respiratory acidosis, we find a forum on carbon dioxide on ixbt , we order a carbon dioxide monitor (at first almost went in the wrong direction and did not buy an oxygen monitor - it certainly would not show anything special). After the transition to permanent ventilation, all the first 8 stages of symptoms disappeared within a week.

Open questions for the future:

1) Is it possible to sow plants (many tiers / hydroponics) in a reasonable area that would eat 20-35 grams of CO ₂ per hour, and how much light power do they need for this? In the future, it would be possible to implement a conditionally closed ecosystem in an apartment, just in case. Question on the topic . It must be remembered that not only carbon dioxide is released from breathing.
2) Are there any simple CO ₂ scrubber constructions (i.e., carbon dioxide air purifiers)? I tried to make a prototype based on a solution of sodium and calcium hydroxides - only the basin melted, there was no noticeable reduction in CO ₂ level above the surface. Apparently everything is not so simple.

Summary

1) Seasonal “depression” - it is not only from a lack of light (I ’m fine with this), but also because people sit at home and do not ventilate the room sufficiently (because it’s cold) - and end up suffering from carbon dioxide poisoning gas.
2) The maximum comfortable level of carbon dioxide - 700-1000ppm and below, to keep it at this level can only be permanent ventilation - constantly open the vents or a system of ventilation. Without ventilation, this level will be exceeded after 2 hours when 1 person is in the room. For ventilation at large facilities - it is fashionable to implement power management by measuring the concentration of CO ₂ in the exhaust air - in order not to drive the air automatically when everyone leaves the office (the enormous power goes to heating / cooling).
3) "Spending more time in the fresh air" for the future - will not work. How much time you spend in a non-ventilated room - so many negative consequences and get.
4) As it turned out, Nootropil, known to many, seems to simply compensate for oxygen deprivation in non-ventilated premises, and therefore has a positive effect where doctors do not expect it. Better and safer just to have good ventilation.
5) Every ruble saved on an office with good ventilation will be more than repaid by reduced efficiency of employees at the end of the working day.
6) According to the results of calculations, in small conversations without constant ventilation with fresh air (not air conditioning!), The allowable time for 5-10 people without cognitive decline is no more than 10-20 minutes.
7) Cold air! = Fresh air. The presence of air conditioning does not reduce the requirements for ventilation. It is impossible to close the windows only because the air conditioner is working - it turns out that the gas vans are working.
8) Children need fresh air in winter no less than in summer. Again, airing once a day is not enough. And so as not to "blow out" - there is forced ventilation with heated air.

Well, now you are left alone with your laziness and caffeine addiction :-)

But if you already have a constant influx of fresh air last week, and you still get tired out of the blue - this is not normal, and you should definitely understand the reason.

Update: In response to fair criticism, I should note that this is not a golden bullet, but only one of the options, the check of which is worthless and absolutely safe (the main thing is not to catch a cold). Each case is unique, and in addition to problems with ventilation, a bunch of diseases can lead to the same symptoms.

References:
CO2 limits in other countries (1% = 10'000 ppm):

Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 oncentrations on Human Decision-Making Performance - Directly test cognitive abilities at various levels of CO2 (600-2500ppm). Results from the 17th page.

Wikipedia - shows the levels at which the toxic effect of carbon dioxide begins.