Paul, Hong Kong asked:
I tend to drive with all the windows closed and the recirculation function engaged. This way I keep out the fumes and dust. The flip side is I知 breathing in re-circulated and progressively stale air. My question is, if the car were a perfectly sealed container, how big would it have to be for me to survive in it for a day? I知 trying to figure out how long I can drive in a compact car without running the risk of passing out.
Dr Gisli Jenkins, University of Nottingham:
Interesting question. I offer the following for consideration: 1) What if the driver were able to induce the mammalian diving reflex - which should theoretically reduce oxygen demand extending the duration of occupancy ? 2) What impact would pressure and elevation have on the duration of occupancy ?
I believe you missed one of the points, it is the toxic effect of the carbon dioxide that you would be worried about, not the lack of oxygen. Madidus_Scientia, Fri, 25th Apr 2008
Thank you for the reply. I should have been more specific re the cabin filter. I was thinking that by using the filter he would filter the outside air, thereby eliminating his need to use the recirculator. emer_med, Tue, 13th May 2008
We (2 people) sometimes carcamp in winter, sleeping on the thick futon in the back of the Jeep Cherokee with down converters. One very cold night (-20 F) we closed all the windows completely. I awoke more or less 4 hours later and quickly realized from diving lessons that it was the CO2 effect. One whiff of a high concentration of CO2 and you never forget it. Don't worry, you will definitely want fresh air long before you will die! Few land animal species would last long without experiencing revulsion at high concentrations of CO2.