[Greenbuilding] Wood-burning Cooking, Central Heating, & Hot Water: Advice Needed

[Mary Bull - Greenwood Earth Alliance]

Thanks so much, Corwyn, for the encouraging prognosis!

Mary Bull, Co-director
Greenwood Earth Alliance, Save the Redwoods - Boycott the Gap Campaign
252 Frederick, San Francisco, CA 94117 http://www.gapsucks.org
Chalice Farm and Sustainable Living Center, 748 Montgomery Rd, Sebastopol CA
95472
415-731-7924 - 415-509-1188 chalicenew at earthlink.net


----- Original Message ----- 
From: "Corwyn" <corwyn at midcoast.com>
To: "Rob Tom" <ArchiLogic at yahoo.ca>; "Mary Bull - Greenwood Earth Alliance"
<chalicenew at earthlink.net>
Cc: "GB REPP" <GREENBUILDING at listserv.repp.org>
Sent: Tuesday, February 20, 2007 4:12 PM
Subject: Re: [Greenbuilding] Wood-burning Cooking, Central Heating, & Hot
Water: Advice Needed


>
> On Feb 20, 2007, at 23:42, Rob Tom wrote:
>
> > The reason willow grows so fast is because it, like bamboo, sucks up a
> > lot
> > of water and for that reason, willow isn't a very good choice as a fuel
> > wood IMO.
> >
> > That opinion seems to be confirmed by the btu output per unit weight
> > numbers as compared to other wood species, willow having the lowest of
> > all
> > the wood species (hardwood and softwood) listed , at 13.15 million Btus
> > per cord. (Compare this to 21.59 milion Btu/cord for maple, 26.39 for
> > r/w
> > oak).(source: in "Handyman in~your-pocket" by Young & Glover))
>
> I am going to have to disagree with Rob here.  Cord is a measurement of
> volume NOT weight (128 ft^3).  In fact, different species of trees
> produce wood of very similar BTU per (dry) WEIGHT.  Thus, although
> willow will take up more room in your basement for equivalent heating,
> it won't be any less heat per pound.  Moreover, a less dense wood will
> burn faster and hotter, making it more suited to cookstove heating.
> Traditionally, wood burning cookstoves were fed with small pieces of
> low density woods.
>
> > Aside from the fact that you'd have to burn twice the volume of wood to
> > get the same heat output as about 1/2 the volume of a "good" firewood
> > (and
> > presumably with twice the emissions),
>
> I can't imagine why you would get twice the emissions.  The air between
> the cellulose molecules isn't producing any pollution.  Faster, hotter
> burning will actually produce less pollution.
>
> > with high water content woods like
> > willow, there's the risk that impatience and/or improper drying will
> > result in too-wet wood being burned and that results in more wood than
> > necessary being consumed (ie to cook off the excess moisture), dirtier
> > emissions and higher risk of creosote formation and attendant higher
> > risk
> > of chimney fires.
>
> True enough,  wet wood, is the bane of all wood burning, however
> coppised willow will be small diameter, and thus dry much faster than
> large chunks of oak.
>
> Thank You Kindly,
>
> Corwyn
>
> -- 
> Corwyn
> Kermit didn't know the half of it...
> http://www.greenfret.com/
> corwyn at greenfret.com
>
>