[Greenbuilding] Fireplace questions

[Corwyn]

On Nov 08, 2006, at 11:41, Bruce Donelson wrote:
> On Nov 06, 2006, at 23:22, Bruce Donelson wrote:
>>> Any fireplace that lays any claim to efficiency will burn outside air
>>
>> Do you have data for this?  I don't see how outside air helps (in a
>> house where a furnace isn't running simultaneously).  Is the stack
>> temperature lower in an outside air fed fireplace?
>
>  No, it is higher, because it does not mix such large volumes of air 
> into
> the exhaust.

All right, how about heat flow per hour?  In other words, if the 
combustion temperature is the same, the air leaving the chimney will 
take a given amount of heat with it.  If that is the same with or 
without outside air being fed into the fireplace, then you are losing 
the same amount of heat, and the outside air isn't helping you.  But 
without real data we are just theorizing in the wind.

>     A fireplace with glass doors does not require a source of air to 
> confine
> the smoke to the chimney. Without the glass it needs air for 
> combustion and
> it needs air flow to swoosh the smoke back up the chimney and keep it 
> from
> mixing with indoor air.

I wasn't arguing against glass doors, just outside air.

>>> Big net energy loss.
>>
>> Again, only if there is a furnace running at the same time.  People
>> heated their houses for centuries with fireplaces.  If they were a big
>> net energy loss, they would have all frozen to death.

> A century ago in Oregon people built log houses. Trees were a nuisance 
> and
> prevented the growth of crops and livestock feed. They used to figure 
> that
> as many trees as it took to build a house was how many it took to heat 
> it,
> each year. So if you used 20 cords of wood to heat your house, that 
> left you
> more cleared land, which was the point anyhow. I personally know 
> someone who
> moved into an uninsulated dome in Oregon in the 70's and cut 23 cords 
> of
> wood to heat it that winter. And it wasn't very warm, mostly. He just
> figured that's what you did in Oregon.

Right, so as I said, not a big net energy loss, just not very efficient.

Thank You Kindly.

Corwyn

-- 
Corwyn
Kermit didn't know the half of it...
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corwyn at greenfret.com