[Stoves] RE Drying of wood

[Crispin Pemberton-Pigott]

Dear Richard

I think he calculated on the basis of cost.  It was huge but very cheap.  As 
you go deep it costs a lot more per mm of internal height.

He did no excavation and it was made from cement block as I recall, not even 
brick.

Farmers tend to optimise for cost and use a lot of low cost labour.

Regards
Crispin

----- Original Message ----- 
From: "Richard Stanley" <rstanley at legacyfound.org>
To: "Crispin Pemberton-Pigott" <crispin at newdawn.sz>; "Discussion of biomass 
cooking stoves" <stoves at listserv.repp.org>
Sent: Monday, January 08, 2007 12:36 AM
Subject: Re: [Stoves] RE Drying of wood


Crisin,
Ref the biodigester and heat loss,

You say that he had a "massive digester only 1.5 meters deep...
Optimum is to minimalise the surface area to volume ratio, defaulting
to deeper, rather than larger diameter--if in ground heat retention
is your concern. The last thing I should think, is that you want is a
large top surface exposure to air as this is where most of the heat
will go.
Richard Stanley