[Stoves] oxygen percentage in air ( same altitude ) and wood stove performance

[rajan_jiby at dataone.in]

Dear Crispin,

>
> Message: 2
> Date: Mon, 30 Jan 2012 10:58:19 -0500
> From: "Crispin Pemberton-Pigott" <crispinpigott at gmail.com>
> To: <rajan_jiby at dataone.in>, "'Discussion of biomass cooking stoves'"
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] oxygen percentage in air ( same altitude ) and
> wood stove performance
> Message-ID: <0a9b01ccdf68$062d32c0$12879840$@gmail.com>
> Content-Type: text/plain; charset="us-ascii"
>
> Dear Rajan
>
>
>
> It is not possible for the O2 level to be significantly different, but 
> there
> is a chance that the humidity of the air is different.

Humidity could be different.

>
>
>
> Assuming you have fuel with the same moisture content in both places, the
> absolute humidity (mass of water per cubic metre) can make a small
> difference. I have noted this when testing 'racing stoves' a few years 
> ago.
> When it is really humid the performance deteriorated very noticeably.
>
>
>
> Perhaps I should first ask, what is the performance difference you have
> noted?

The flame was looking much brighter/better/hot. No measurements taken.

> Are you taking a fuel sample and using it at both locations?

Yes.

> It is
> more likely to be the fuel.

No.

Regards,

Rajan

>
> From: stoves-bounces at lists.bioenergylists.org
> [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of
> rajan_jiby at dataone.in
> Sent: Monday, January 30, 2012 10:10 AM
> To: stoves at lists.bioenergylists.org
> Subject: [Stoves] oxygen percentage in air ( same altitude ) and wood 
> stove
> performance
>
>
>
> Dear All,
>
>
>
> What would be the difference we can expect in the percentage of oxygen in
> the urban and rural air ( altitude remaining the same ) ?
>
>
>
> I am asking this question since I found the same wood stove with the same
> fuelwood performed better in a rural area compared to an urban area (
> altitude being sea level at both places ). I am not able to find any 
> reason
> except a possible difference in the oxygen percentage in the air at the 
> two
> places.
>
>
>
> Has anybody else also experienced something similar ?  Or is it just my
> illusion ?
>
>
>
> Hope to get some clarification from somebody.
>
>
>
> Regards,
>
>
>
> Rajan

> ------------------------------


Dear AJH,

>
> Message: 3
> Date: Mon, 30 Jan 2012 16:20:01 +0000
> From: ajheggie at gmail.com
> To: Discussion of biomass cooking stoves
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] oxygen percentage in air ( same altitude ) and
> wood stove performance
> Message-ID: <201201301620.01880.ajheggie at gmail.com>
> Content-Type: text/plain;  charset="utf-8"
>
> On Monday 30 January 2012 15:09:58 rajan_jiby at dataone.in wrote:
>> Dear All,
>>
>> What would be the difference we can expect in the percentage of oxygen
>> in the urban and rural air ( altitude remaining the same ) ?
>
> Interesting question Rajan, my first guess was that because of wind and
> rates of diffusion any concentrations of pollutants and CO2 would be
> rapidly  levelled off but I see a 2008 news report that polluted city air
> can drop to 15% O2 compared with the normal 21% we expect to see.

This is the point of my doubt.

>
> Although air pressure drops with altitude it should not affect the gas
> volume ratios.

Volume ratios are not affected. But air density will be differrent.

>>
>> I am asking this question since I found the same wood stove with the
>> same fuelwood performed better in a rural area compared to an urban
>> area ( altitude being sea level at both places ). I am not able to find
>> any reason except a possible difference in the oxygen percentage in the
>> air at the two places.
>
> Have you considered change in humidity affecting the equilibrium moisture
> content of the wood?

I have not considered the humidity. But it was the same wood sample.

>
> AJH
>