[Stoves] CO- and Oxygen-affinity to haemoglobine

Crispin Pemberton-Pigott crispinpigott at gmail.com
Wed Oct 27 14:40:56 CDT 2010


Dear Friends

Well I don't know that I am representative of the model but my combustion
efficiency is as follows (background CO = 0 ppm)

As the pump cleared the air from the sample pipework, the concentration
rose. The concentration of CO2 also rose as I was holding my breath.

CO/CO2 ratio at 1% CO2 concentration @ 1 ppm CO = 1/10,000 = 0.010% (holding
breath)
CO/CO2 ratio at 2% CO2 concentration @ 2 ppm CO = 2/20,000 = 0.010% (holding
breath, gas analyser complaining that I am blowing into the tube)
CO/CO2 ratio at 3% CO2 concentration @ 3 ppm CO = 3/30,000 = 0.010% (holding
breath, steady pressure)
CO/CO2 ratio at 4% CO2 concentration @ 4 ppm CO = 4/40,000 = 0.010%
(starting to feel the pinch)
CO/CO2 ratio at 8% CO2 concentration @ 4 ppm CO = 4/80,000 = 0.005%
(starting to gasp)

This had to be sampled during a long breath-holding event so it is possible
that the CO/CO2 ratio changes (combustion gets more efficient) as the O2
level in the bloodstream goes down. It seems it does not get worse. I
repeated this test and got exactly the same result. The CO2 rose to just
over 8% (about 8.2). I think if I could hold my breath long enough it might
get to 9%, or about 1/2 the CO2 Max value of 18.[?].

To those who commented on the poisoning idea of body-generated CO, please
remember the difference between the concentrated exhaust gas (my exhaling)
and the dilute intake CO level that constitutes the 'exposure'.

So assuming I am not exhaling volatile organic compounds containing carbon,
and no Black Carbon particulates, my combustion efficiency is 99.99%. I like
four 9's efficiencies.

A coal stove test of the production version of the GTZ 7.1 last week showed
a best value of 0.07% so we have a way to go to match the average human. Of
course we haven't been working on it for as long....

If you sit in a hermetically sealed room you will expire from a loss of O2
long before you gas yourself with CO.

Regards
Crispin in Windy Waterloo





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