Scary info about air quality

[Jeremy Harris]

It was still a Renault 5, but the Gordini version, with the 5 speed gearbox and a bit more poke than the smaller engined R5s.  As the car only weighed 450kg the power to weight ratio was a wee bit better than in the R5 donor car.

[mike2016]

I hope my bedroom foobot is just badly calibrated!

 

[Jeremy Harris]

That looks mighty high to me during those peaks.  IIRC, the peak readings I recorded in our old house were around 1600ppm or so.

[Hastings]

23 hours ago, Ed Davies said:

... a room would have to be pretty small and well sealed to get to life-threatening levels overnight. It'd be much more likely you'd wake in the morning with a horrid hangover.

 

Death while sleeping is certainly more common in smaller spaces - eg. holiday cabins.

I worked for periods out of a converted shipping container in Antractica that had a Propane heater and an air vent in the door. The  trouble is, the vent needed to be screwed closed when the cabin was unoccupied, in order to prevent snow blowing inside, so that left the possibility of not opening it, going to sleep with the heater on (temps dropping to -30C made that very tempting) and not waking up again.

[Jeremy Harris]

The problem with burning propane in a confined space is that incomplete combustion will generate CO, and as mentioned earlier, unlike CO₂, CO is very definitely a silent killer.

[Ed Davies]

CO (carbon monoxide) and CO₂ (carbon dioxide) get you in very different ways.

 

Carbon monoxide's problem is that it takes up the place in your haemoglobin which you'd much prefer to be taken by oxygen resulting in your tissues not getting that oxygen. We (most (all?) mammals (animals?)) have not evolved to detect that condition, or other causes of hypoxia, as it so rarely happens in nature that there's been no selection pressure for it. You have to go out of your way to look for particular symptoms to detect it, e.g., the reduction of colour vision that tipped off @JSHarris. You're not likely to notice those if you're asleep.

 

Increased carbon dioxide, on the other hand, mostly gets you by preventing you getting rid of waste CO₂ generated in your body so that it builds up in your blood steam. This is the quicker effect of not breathing so it's what we've evolved to detect. The “lungs bursting” feeling you get if you hold your breath too long comes from excess CO₂.

 

CO₂ also bonds to haemoglobin a bit at a different site from that used to carry oxygen but which does have the effect of reducing its oxygen carrying capability but, AIUI, that's a more minor effect.