Perhaps a variant on the Ecofan would work.
http://www.caframo.com/ecofans.htm
I have received one of these, but not yet had a chance to try it out.
Lucky you, we could use one of those. I think they're not very cheap.
I have heard
from others that they work as advertised.
Good reports.
(Placed on a wood stove, they move
warmer air into the room instead of just convecting upward. In our
place, this
will replace a small electric fan I have used for precisely that purpose.)
That's what we'd use it for.
As I understand it, there is an integral Peltier device that
produces electricity
from the heat (actually hot/cold differential) to power the electric
motor to turn
the fan. I see no reason the same technology could not be used to
power a small
blower instead of a fan blade.
Peltier devices were much discussed, and IIRC they may have been
tried, but once again no answers emerged. Thinking about it again now
I wonder where the cold part would come from. The most recent of
these discussions I mentioned was some time ago and I don't recall
all the detail other than what was discussed and that no real
solutions were found.
Darryl McMahon
"Ideal would be the heat of the stove itself"
Has anyone considered a stirling powered fan?
http://www.stirlingengine.com/
Mike
Yes, but again it didn't work out, and again I don't recall why not.
A disadvantage would be that it would not be integral to the fan and
would up the cost and the difficulty of simple local construction (I
think).
Sorry to be so discouraging, there are some smart people at the
STOVES list at Crest and they were pretty thorough, several times.
But there are plenty of smarts here too, don't let me put a damper on
it.
Thanks.
Keith
Keith Addison <[EMAIL PROTECTED]> posted:
> >Greetings,
> >Regarding Tom Reeds woodgas camp stove and its requirement for a
> >primary air source (battery powered), what about a mechanical windup
> >clockwork system to drive the fan. You can visit the web site
> >www.freeplayenergy.com to see what I mean.
> >Have fun!
> >Derrick
>
> Greetings Derrick
>
> Thanks for the suggestion. Clockwork radios seem to work well, but
> for these stoves, clockwork got tossed around a lot in those
> discussions (along with just about everything else), and each time it
> got ruled out, I don't recall just why offhand. I have been to that
> site though, for that purpose.
>
> Ideal would be the heat of the stove itself, and/or convection,
> something integral to the stove, to power the primary air fan, but,
> despite some elegant ideas, nothing practical has emerged. I believe
> one reason for that is that so little is known about how these stoves
> work - inverted downdraft gasifying charcoal-producing stoves, is
> what they are, real catchy name, eh? Tom Reed, who surely knows more
> than anybody about them, once said he thought about 25% of the
> science of IDD woodstoves is known. Probably as more is learnt the
> answer to integral powering of the fan will emerge.
>
> This is the one we made:
>
> http://journeytoforever.org/teststove.html
>
> It works well, some quite advanced features, quite widely copied, but
> it's still not satisfactory. But, use a small powered fan for the air
> supply and it works excellently.
>
> Thanks again.
>
> Keith
>
>
> >Keith Addison <[EMAIL PROTECTED]> wrote:
> >Greetings Pan
> >
> > > Greeting Keith
> > >
>
> <snip>
>
> >Another missing piece is what Robert was saying about Tom Reed's
> >woodgas camp stoves - they work very well, but only because there's a
> >battery to drive a fan for the primary air supply. I've been part of
> >several intensive discussions with the stoves people on how to
> >achieve this level of efficiency and control without a power source,
> >and it's got nowhere, so far. I sort of gave up our work with woodgas
> >stoves for the time being, hoping to find better answers for cooking
> >with liquid biofuels rather than biomass. I have found some answers,
> >much more to be done still.
> >
> >Not all the work with improved woodstoves is convincing. Often the
> >target communities also aren't convinced. Some comparisons have found
> >that the old three-stone woodfire can be as efficient or more
> >efficient if it's done well. It might be a better idea to find the
> >best fire builder in the valley and get him to give everyone else
> >lessons on how to do it properly. There might also be a bigger need
> >for good chimneys to take the smoke out than for improved woodstoves.
> >Or ethanol gel, eh? Or a good vegoil stove design that a village
> >blacksmith can produce.
> >
> > > Thanking once again on behalf all the developing countries ,
> > >students and teacher can do better social work with this new
> > >products and good hope to have the great green future for the
> > >needful based on the biomass fuel.
> >
> >Thankyou Pan, but if you thank me I think you have to thank everyone.
> >Most of what I know about biofuels I've gained by applying what I've
> >learnt from list members here, for which I'm MOST grateful.
> >
> >Best regards
> >
> >Keith
> >
> >
> > >
> > >sd
> > >Pannirselvam
>
> <snip>
--
Darryl McMahon http://www.econogics.com/
It's your planet. If you won't look after it, who will?
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