[Stoves] Why not high mass stoves?

Dean Still deankstill at gmail.com
Sat Nov 1 21:08:56 CDT 2014


Hi Huck,

Have you read Sam Baldwins book  on Biomass Stoves? He explains a lot about
heat transfer. I copied a few sentences from Chapter 3 page 55 (I think)
for you:

"Thus, lightweight walls have the intrinsic potential for much higher
performance than massive walls due to their lower thermal inertia.
This
does not, however, necessarily mean that a lightweight stove will
automatically
save energy or that a massive stove cannot. For a lightweight
stove to save energy its heat loss to the exterior must also be
minimized
and the convective and radiant heat transfer to its pot must be
optimized.
Conversely, massive stoves can and sometimes do save energy despite
their
large wall losses. Such stoves can save energy if the convective and
radiative heat transfer to the pot is carefully optimized. "

Best,

Dean

On Sat, Nov 1, 2014 at 5:46 PM, Huck Rorick <huckrorick at groundwork.org>
wrote:

> In Aprovecho’s very well written paper “Design Principles for Wood Burning
> Cook Stoves” they recommend against high mass stoves such as the Lorena
> stoves they had worked with many years back.
>
>
>
> It is obvious to me why you would want an insulated stove to avoid loss of
> heat from the fire to the outside as opposed to the pot.  But I am very
> puzzled as to why a sheet metal stove would be better than a heavy clay
> one.  It seems to me that heat from the fire will be transmitted much more
> quickly through the thin walls of a metal stove (without thermal insulation
> such as ceramic fiber) than through a massive earth wall.  To orient myself
> I checked the thermal conductance of a few materials in Watts/meter/degree
> Kelvin.  Insulating materials such as ceramic fiber are about .03-.04,
> insulating brick .15, dry earth 1.5, stainless steel 16, and carbon steel
> 43.  Compared to steel the earth is a good insulator.  An interesting
> aside, dry sand is similar to insulating brick at .15.
>
>
>
> The fact that the high mass stove stores the heat in the stove body rather
> than immediately transferring to the outside air as a metal stove would do
> wouldn’t seem to change the heat lost from the fire.
>
>
>
> Huck
>
> Huck Rorick
>
> Executive Director
> Groundwork Institute
> 2640 Silvercrest Street
> Pinole, CA 94564
> Phone: 510-222-4111
> email: huckrorick at groundwork.org
> Website: *www.groundwork.org <http://www.groundwork.org>*
>
>
>
>
>
> _______________________________________________
> Stoves mailing list
>
> to Send a Message to the list, use the email address
> stoves at lists.bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
>
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>
> for more Biomass Cooking Stoves,  News and Information see our web site:
> http://stoves.bioenergylists.org/
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20141101/a8a63c61/attachment.html>


More information about the Stoves mailing list