Re: Suspension losses

On Wed, 15 Jan 2025 13:48:14 +0700, John B. <slocombjb@gmail.com>
wrote:

On Tue, 14 Jan 2025 07:40:45 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:
>

On Tue, 14 Jan 2025 16:04:11 +0700, John B. <slocombjb@gmail.com>
wrote:
>

I don't know whether you know this but when using a stove to heat a
room put the stove in  the opposite side of the room from the chimney.
Then run the stovepipe from the stove straight up from the stove to
the ceiling and then along the ceiling, using mounts to separate the
stove pipe and ceiling, of course, across the room to the chimney.
>
That way you get more heat from the same amount of wood.

>
Bad idea.  When I bought the house in 1974(?), that's roughly what the
previous owner had done.  I couldn't find a photo, but it was a rather
large "pot belly" stove that leaked air from every seam.  It was
located at one end of the living room with about a 10 ft horizontal
flue pipe to where it connected to the a 5 ft vertical insulated
external pipe (Metalbestos) that acted as a chimney pipe.  It didn't
work for a variety of reasons.  The big one was that for the "draw" or
suction to be able to move sufficient hot air up the chimney pipe, the
inside of the chimney pipe had to be hot.  In order to heat the pipe,
the hot air from the stove has to rise, which is rather awkward with a
10 ft horizontal uninsulated pipe with nowhere for the hot air to
rise.  Getting a fire started was possible, but difficult and VERY
smoky.  Cleaning the ash out of the horizontal section was difficult
because the previous owner had neglected to install a "T" where the
pipe changed from horizontal to vertical.  Even if there was a "T", it
wouldn't have worked because rising hot air does not like making sharp
turns.
>
In other words, it didn't work and horizontal flue pipe are a really
bad idea.  I had to remodel the living room, move the stairs going
through the floor, replace the pot belly with an airtight stove, and
extend the external chimney pipe to 12 ft, in order to fix the
problems.  Although I don't completely understand how it works, I've
found that the "efficiency" of the system is controlled by how much
time the hot gasses remain in the stove and whether the wood is
sufficiently dry (under 10% moisture).

>
Your description doesn't sound like the systems built in and used in
about every building in my home town.

The US east and west coast climates are very different. 

Often built from red brick these
chimney reached from the cellar to above the roof top.

In 1989, we had the Loma Prieta Earthquake (Magnitude 7.1).  In my
neighborhood, Most of the brick chimneys cracked at the mortar lines,
broke off at the roof line, or fell onto the house destroying the
roof.  The only chimneys that survived were those that were in some
way reinforced with rebar or had a steel pipe lining.  At the time, I
had two chimneys.  One was 8 inch in triple wall DuraVent for the
downstairs rooms.  The upstairs chimney was 6 inch Metalbestos double
wall.  The upstairs Metalbestos chimney had to be straightened.  The
longer downstairs Matalbestos collapsed and ended up on the ground in
pieces.  8 inch pipe was too large for the downstairs stove, so I sold
the pieces to a neighbor.  I eventually removed most of the 8 inch
pipe and decided not to replace it because it was workshop and storage
which didn't need heating.  When you live in earthquake country,
construction practices tend to be rather different.

Then had a
small opening in the bottom often with a loose fitting metal door to
allow cleaning anything they might fall down the chimney and to allow
the free flow of air up through the chimney. Thus the hotter, lighter,
"smoke" flowed up the stack.

Yes.  My parents house in Smog Angeles was like that.  However, the
brick fireplace was only used during the winter holidays.  The rest of
the year, a natural gas furnace was sufficient.

As for an air tight stove that is a bit puzzling. How do you  have a
fire in an air tight enclose?

Air tight is a rather bad name.  What it means is that the air intake
to the stove could be controlled with the air intake almost completely
closed.  That allows me to slowly burn large logs.  Having air coming
into the stove from cracks in the firebox and around the door causes
problem with control, where the oscillates between almost going out
and flaring up.  With no air leaks, I can set it and forget it.

Incidentally, shutting down the stove by strangling the air intake
causes other problems.  The fire produces large amounts of CO (carbon
monoxide) and creosote (flammable tar) if there's not enough air. It's
also the way one makes charcoal and char cloth (for starting a camp
fire with a flint and steel).
<https://en.wikipedia.org/wiki/Char_cloth>

EPA approved wood burning stoves have two small air intakes that
cannot be blocked or closed down that effectively prevent producing
carbon monoxide and creosote.  My current stove is not up to date on
EPA approvals, which generally requires a catalytic converter.



--
Jeff Liebermann                 jeffl@cruzio.com
PO Box 272      http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann      AE6KS    831-336-2558