From: John De Armond
Subject: Re: Woodstove fire building 101?
Date: Sat, 22 Oct 2005 13:17:42 -0400
On Sat, 22 Oct 2005 08:42:14 -0700, "Bill" <firstname.lastname@example.org>
>What do you do with your woodstove when you have several days of mild
>temperatures and just need a "little heat"?
I turn on an electric space heater.
>Seems to me that to get my woodstove working properly (draft, etc.), I need
>to always build a "blazing inferno" to get it warmed up to operating
>temperature (to get the temperature gauge on the chimney into the "burn
> zone"). And if I don't do this and build just a little fire, it does not
>seem to work properly.
Just build the little fire and don't worry about the gauge.
>Because I just installed my stove this summer, and have obtained my firewood
>within the last month from the mountains (F.S. Permit), my wood pile has not
>had a year to dry out. Although I've been told that the wood in the area I
>got it from has been down for over a year, some of it seems to be wet and
>other wood very dry. I noticed that a log I placed in the wood stove was
>"hissing" - sounded like steam coming out. (First time I have noticed this
>Anyway is there a way to tell if a piece of wood is dry or not?
After you gain some experience: by look and feel of it. Dry wood is
generally brown to gray with radial cracks on the ends and is much
lighter than green wood.
Before experience: if you really want to know, get a wood moisture
>The instructions for my wood stove say to leave the door open a little at
>first to get the fire going. But if I do this before I have a good draft,
>smoke comes out the top of the door sometimes (not always). I was thinking
>of installing a fan which would bring outside air into the house and provide
>"positive air pressure" inside the house and force the smoke up the chimney
>when first starting a fire. Comments?
It's probable that your draft isn't good enough. Check for
obstructions in the chimney. If your stove has any bypasses, such as
a catalyst bypass, make sure it is open when firing.
The fan may or may not work. I've seen that tried and for whatever
reason, the smoke still came out into the house.
My first stove had inadequate draft so I made a smoke ejector. This
consisted of a piece of copper tubing, drawn into a point by heating
and stretching with a come-along, inserted into the top elbow so that
it blew across the elbow and into the horz run to the chimney. This
was hooked to a blower. The jet of air entrains smoke from the
chimney, creating a significant suction.
I used an old car smog pump for my blower. With the blower on, the
draft would literally lift ash particles from the bed and suck them
out. I'd run this thing for a few minutes after I closed the door to
get a white hot coal surface on the wood.
I simply used a large punch to poke an inward facing hole in the elbow
(single wall pipe at that point, inserted the copper tube with a
friction fit, and silver-soldered it in place. The silver solder
withstood even the occasional chimney fire.
From: John De Armond
Subject: Re: wood stack temp?
Date: Fri, 03 Mar 2006 14:22:53 -0500
I agree. If the OP has a conventional chimney then his first concern
should be in minimizing buildup ("creosote"). I took a slightly
For my first house when I was too poor to pay a heating bill, I
designed and built a central wood furnace. I designed it to be
"condensing". That is, to cool the flue gas below 212 degrees. More
typically, around 170. The smoke pipe and the heat exchanger both had
drip legs that would drain a couple of gallons of gunk a week.
Anticipating heavy deposits, I designed the chimney to be blast-proof,
made of a steel pipe liner and reinforced concrete and for a reason. I
installed a gas burner/eductor jet in the chimney, the later to force
draft. About twice a season, I'd light the gas get to set the
creosote on fire, then turn the eductor on to force a nice draft. The
blaze was spectacular!
As it burned down, I'd lower an M-80 (available at the Farmer's Co-op
back then) down the chimney about half way on the end of a string on
the end of a long pole. The explosion would loosen the charred
creosote and it would fall to the ash pit at the bottom of the
chimney. Instant chimney maintenance without ever leaving the ground!
The eductor was very handy on a daily basis. It consisted of nothing
more than a low pressure air jet positioned to shoot up the chimney.
When a stream emerges from a nozzle, the stream contracts to a minimum
diameter and pressure at a point away from the jet called the vena
contracta. I positioned the jet so that it fell at the centerline of
the smoke pipe from the furnace. When the air was turned on, the jet
created a powerful draft, the Bernoulli effect in reverse. By
flipping a valve, natural gas was piped to the jet which turned it
into a powerful blowtorch.
I used an automotive smog pump driven by an electric motor as the
source of compressed air. The jet was nothing more than a hunk of
1/2" copper tubing that had been clamped in a pipe vice and then
stretched with a come-along while being heated to form a tapered
nozzle with an opening about 3/8" in diameter. That was
silver-soldered to a hunk of black iron to make the jet.
Using this jet eliminated any smoke from the house. I'd simply flip
on the motor a few moments before opening the furnace door and all the
smoke would have been sucked up the chimney. A strong enough draft
kept any new smoke from coming out.
It also made lighting a new fire trivially easy. I made an igniter
that consisted of a steel cup made from 3" exhaust tubing about 2"
deep and filled with a porous refractory. It was positioned right
under the grate. Welded to this cup was a piece of 1/2" black iron
pipe. This pipe extended through the furnace wall where a funnel
To fire the furnace, I poured about a pint of kerosene down the pipe
which saturated the refractory. An oil burner igniter lit the
kerosene. Then I turned the eductor on which turned the burning
kerosene into a virtual blowtorch. I had a timer on the motor which
was set to 10-15 minutes, depending on how well seasoned the wood was.
Then I just walked away.
I later fitted a conventional oil burner to the furnace so that I
could light the fire that way and I could burn oil when I didn't feel
like starting a wood fire.
Whew, got a little carried away there with my typing.....
On Fri, 3 Mar 2006 04:41:54 -0800, "Ray Manning"
>Depends on what you want to monitor I suppose. I place mine above because
>I'm interested in reducing creosote in the flue by keeping the temperature
>of the exaust hot. If you place it below, I suppose you could monitor the
>heating box temperature but I'm not sure what value that has.
>"A Veteran for Peace" <email@example.com> wrote in message
>> Is it better to place a temp. guage above or below the damper on our
>> wood stove?
>> Impeach Bush ! a noble cause
>> And visit.. alt.impeach.bush
From: John De Armond
Subject: Re: Combination Oil/Wood Water Boiler
Date: Sat, 31 Mar 2007 19:00:23 -0400
On Sat, 31 Mar 2007 11:43:01 -0600, "firstname.lastname@example.org"
>Larry Caldwell wrote:
>> First thoughts:
>> A 40 gallon reservoir is too small for domestic hot water, much less
>> domestic heat. You are going to have to keep a wood fire going ALL the
>> time to get even heat, one of the great advantages of hot water heating.
>> I would think you would need at least 500 gallons of water storage, and
>> even with that the oil burner would come on a lot.
>> Efficient wood combustion requires a high temperature in the fire box,
>> at least 500 degrees and 800 degrees is better. A water jacket very
>> efficiently cools the fire box. In the 19th century, steam technology
>> took a great leap forward when they invented the fire tube boiler, but
>> these folks brag about not using tubes?
>In industrial applications tube type boilers lose a lot
>of their efficiency unless accumulating soot is removed
>frequently. I expect the same is true for smaller wood
>fired applications. Even when the wood is free, such an
>operation is still labor intensive.
Wood furnaces don't soot up like industrial boilers where the crud
that collects on the tubes is often semi-fused. Creosote collects in
the upper parts of the fire box and in the chimney but it isn't as
adherent as fused fly ash. My experience is that in the off-season
the stuff absorbs moisture, curls off the surfaces and either falls
away or can be easily brushed away. Either way, not a big problem.
I'm not surprised to see Larry running off about what he knows
nothing. If I could inject a little actual experience with a water
jacketed wood furnace.
Last summer I helped a friend install a pad-mounted outdoor automatic
water jacketed wood burning furnace. I'm sitting here and for the
life of me I can't recall the brand name. Sorry.
This furnace is about chest high and the combustion chamber reaches to
within a foot of the ground and about 6 inches from the top. It is
water jacketed on all 4 sides and the top. Water is at atmospheric
pressure with automatic fill and an atmospheric condensing vent.
The fire control is a solenoid-operated damper and a squirrel cage
forced draft fan. A thermostat in the water jacket controls the fan
and damper and keeps the water at 180 deg.
He heats an uninsulated country house and a 6,000 sq ft insulated
metal building shop plus hot water through a 40 gallon tank (more than
The unit is very well insulated - even at high fire no place on the
outside rises more than 20 deg F over ambient.
The firebox is huge, capable of holding 7 or 8 8-10" diameter unsplit
logs, which is what he burns in it. This loading is good for a day to
a day and a half even in the coldest weather we had this year (low
teens). He built a fire last fall and it burned all winter, only
letting it burn out last week.
The fire either burns at full fire with forced draft or is completely
deprived of air. This works very well. There is a little smoke
during the transition to full fire but the forced draft quickly brings
the smothered fire back to life.
The flue is about 4 ft of 8" stainless steel welded sheet metal pipe
that sticks straight up out of the top. I was there recently with my
infrared pyrometer. The weather was 50ish. The hottest spot on the
flue at high fire was about 250 deg F. Just right. So much for the
Caldwell theory on water-jacketed furnaces.
I asked him to keep track of the wood he burned. He did but not very
well. He previously heated his house with a conventional wood stove
and said that this thing used far less wood than the wood stove even
though it heated two buildings.
The 40 gallon tank is more than adequate for two people. In reality
the furnace can heat the water in real time so the tank capacity
doesn't matter. He has an electric heater for summer use.
At the end of the season the walls of the firebox/water wall above the
active burning area are coated with a thin shiny layer of jet black
creosote. Really more of a film, as it retains the texture of the
stainless steel underneath. This film established itself early on so
I don't think it will get any thicker.
I admit that I had my doubts about a water wall furnace but since the
company offered a money-back guarantee and this was otherwise the best
unit we could find, he bought it. I'm impressed. Very impressed. I
have a feeling one of these will appear at my place to replace a wood
From: John De Armond
Subject: Re: which is better to split wood.
Date: Sat, 02 Jun 2007 14:45:41 -0400
On Sat, 02 Jun 2007 07:55:57 -0700, after several days of intestinal upset, Sheldon
>Harry Kreep wrote:
>> A Veteran wrote:
>> > I just got some green wood and some is Madrone.
>> > some Redwood and Pine. Is it easier to split now or after it dies?
>> > approx. 10 inches in dia.
>> > --
>> > when you believe the only tool you have is a hammer.
>> > All problems look like nails.
>> Rather than give opinions, here is a chart of all woods with heat
>> value, splitting characteristics, etc.
>Not even close to ALL woods.
>And that chart clearly indicates that redwood and pine are rated
>poorly as firewood. I have acres and acres of mature white pine on
>my property (50'-60' tall), I only wish someone would take it, for
>free... alas no one wants it, certainly not for firewood, not even for
>mulch. I can get a lumber mill to take it, and they'd pay me, but
>they'd rape the land with their heavy equipment.
NO, actually they'll come in, grab all the trees, remove the stumps and haul them
off, smooth the land and if you like, plant new seedlings. That's the way it's
worked every time I've sold off a lot of pulp wood, my last one about 2 years ago.
Why do I suspect that you don't actually own any pine? It's far too valuable for
someone who actually DOES own it not to know.
>Many of my neighbors
>heat with wood, but you couldn't give pine cord wood away... in fact
>if anyone tried salting a load of cord wood with pine they'd want to
>hang them... not only is pine poor firewood, pine fires are
>dangerous... burns like christmas trees.. hey, that's what pine is.
I don't think I'd go out and cut and split pine for firewood but if it were given to
me, like, say, dump trucks full of pine slabs from a friend's lumber mill, then hell
yeah, I'll burn it. I did so for years in my homemade central wood furnace. You
don't burn it exclusively and you don't smother the fire down much. If you obey
those two rules then pine burns just fine and leaves no creosote in the chimney.
Pine has another very good purpose - when just a little heat is needed, like knocking
off the chill on a spring or fall morning. A stove full of hickory or oak will burn
far too long and make far too much heat. A pine fire lights quickly, burns quickly
and doesn't give off too much heat. And it smells damned fine! Nice to leave the
doors of the fireplace insert stove open to enjoy the flames. I keep a small pile of
nice seasoned pine just for that purpose.
OH, BTW, Harry. Thanks for the wood chart reference. Handy. Confirms my
observations about some locust a friend and I recently got our hands on. Spawn of
the devil to split but lots of heat, close to hickory.
From: John De Armond
Subject: Re: Energy efficient fireplace insert
Date: Mon, 23 Jun 2008 00:24:11 -0400
On Sun, 22 Jun 2008 08:56:18 -0700, "~~NoMad~~" <email@example.com> wrote:
>"Drew Cutter" <firstname.lastname@example.org> wrote in message
>>I want to burn wood in the fireplace this winter. Soapstone is too
>>expensive. Any suggestion on efficient fireplace inserts ?
>The most efficient would be a small free-standing stove sitting out in front
>of the fireplace with a stovepipe plumbed into the fireplace chimney.
I have a very conventional Buck Stove fireplace insert made before the EPA
made 'em expensive. It heated my ~900 sq ft cabin all last winter on much
less than half a cord of mixed hickory and oak. I don't have any idea what
the efficiency is but it has to be pretty good. I heated for less than $50
for the whole season, exclusive of the small amount of electricity necessary
to run the fan.
Here's a photo of it. I only opened the doors for the photograph. It
normally runs with the doors closed and in near-air-tight mode.
I picked up this stove used at an auction for $50. It couldn't have been used
for more than one season, going by the excellent condition it was in.
I do quite a bit of cooking in the stove too, as you can see a couple of
slides over. Not only the steak but also pots of beans and stew and stuff
like that. I usually let the fire burn down to mostly coals. The heat output
is still good even with a low fire like that.
The original fireplace had a heatilator for a fire box which is what the old
gold-colored fan was for. It heated nicely but was uncontrollable. If I
built the fire just a little too large, the front door had to be opened for