From: poutnik@privacy.net   
      
   Dne 09/01/2018 v 01:11 ian Gay napsal(a):   
   > Libor 'Poutnik' Stříž wrote:   
   >   
      
   >>>   
   >> CO2 is heavier/denser then air either,   
   >> having about the same molar mass 44 g/mol as propane.   
   >>   
   >> But the point is - at the same temperature.   
   >>   
   >> Hot enough CO2 is lighter/less dense than cold air,   
   >> and additionally, there is not only CO2,   
   >> but the majority is nitrogen, and also water vapours,   
   >> that further decrease the density .   
   >>   
   >> So gases need not to be very hot   
   >> to be less dense than normal air at ambient temperature.   
   >>   
   >> The gas from a fire climbs up, not falls down.   
   >>   
   >   
   > But does anyone actually have CO2 detectors? Maybe the OP is really   
   > talking about CO detectors. CO is slightly lighter than air, but I   
   > would be surprised if the small difference were significant.   
      
   IMHO, CO is not much concern in outdoor PB gas burning context,   
   as the gas burners have oxygen rich combustions.   
      
   But CO2 is concern, as burning in small volume as in tents   
   can significantly increase CO2 content above safe levels.   
      
   Having CO2 detector at ceiling   
   would have mostly fire safety applications in indoors.   
   For life/health safety it may be better   
   to be at low levels, to avoid false alarms.   
      
   OTOH, CO detector is better to have at ceilings, as it would give   
   quicker response ( hot gases ).   
      
      
   --   
   Poutnik ( The Pilgrim, Der Wanderer )   
      
   A wise man guards words he says,   
   as they say about him more,   
   than he says about the subject.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)