I saw a study showing correlation between cognitive impairment and sub-micron particles in the air. They used candles for the study but coal factories are the large scale concern.

Related to this, I've seen research showing that by the time a room feels stuffy there is enough CO2 to measurably affect cognitive performance. Now I'm much better about remembering to open a window when I'm coding and starting to drag.

Highly recommend getting a cheap CO2 meter. We have a couple around the house. It’s amazing how fast a room fills with CO2 when cooking or having people over (pre-COVID). You can become more attuned to it — I have a pretty good idea what 800PPM feels like compared to 500PPM compared to 1000PPM. Weird party trick too.

What do they feel like for you? I’ve had a CO2 sensor in my office for a long time, and don’t think I can tell the difference between 500 and 1500ppm.

It honestly doesn’t feel like anything. I just ask my body what the number is and it’s always within a hundred ppm. it feels like a guess, but like a guess when you’ve been counting cards so long you know roughly what the count is without consciously keeping track of it? If that makes sense.

A couple of years ago, I started getting headaches. Everything in my noggin appeared normal, and one day I worked with the window open. No headache. So I got my first one, it wasn’t very expensive (€50-100 IIRC) and did some experiments. Sure enough, it would get up to 1800ppm in my tiny office and I’d get a headache.

I’d say the biggest thing it seems to affect is coding. If I can keep it below 600ppm in my office, I can code all day and late into the evening without feeling too exhausted. At about 1k, I start to feel kinda sleepy and tired after awhile.

My wife and kid had fun doing the observations and asking the questions during the experiment. Good times. We used it as a way to teach our son how to do experiments and ethics.

Do you have a recommendation for one? I heard it's quite hard to get accurate ones without paying a lot.

A quick search shows a ton of choices, Are there any models or brands you like, or dislike?

I wasn’t too picky, I ended up with tfa dostmann‘s which seemed reasonable in price point vs accuracy.

Yet another advantage of remote work! How many offices have windows you can open? (I used to work in one that did, because it was in an old mill building. It was great.)

You can breath in your burned fat too, if you wish.