[TheForge] Wood Stove for Shop heat

[Jerry Frost]

Hey all! The winter station "emergency" (Pi$$ Poor 
planning on your part doe's NOT constitute an emergency 
on MY part. Holds true in this circumstance but a 
boatload of OT was welcome. <grin>)

Anyway, heating with wood is the subject I believe. 
<grin>

No reputable manufacturer builds wood burners with 
catalytic converters anymore, haven't for in the 
neighborhood of 5-7 years. The problems with catalytics 
are: Proper use and maintenance resulting in way more 
chimney and hence house fires than necessary. 
Catalytics have to be preheated before they're engaged, 
then they're vrey finicky about the quality of wood you 
feed them, then you HAVE to keep the fire rolling or 
they plug up. Catalytic converters were an idea that 
sounded good on paper but in practice have proved to 
not only be inefficient but outright dangerous in use.

So, over the past decade or so all the good 
manufacturers with the notable exception of Vermont 
Castings, have gone to multiple burn zones. Some of the 
high end manufacturers have taken it to indirect 
combustion so the stove is making charcoal in the wood 
chamber and only burning the gassious byproducts and 
charcoal. These last are typically external wood fired 
boilers but they're extremely efficient and clean 
burning.

A good barrel stove is hard to beat if it's properly 
built. A single barrel will easily heat 1,000-1,200' 
sq/ft with 14' eaves if it's decently insulated. A 
double barrel will heat twice the volume with little 
trouble. You can heat more if you convert the second 
barrel from a simple stack robber (heat scavenger) to a 
forced air stack robber. Simply cut holes in the ends 
of the scavenger barrel the same dia. as a 15 gl. 
grease barrel. Weld a couple grease barrels together so 
the ends hang out a few inches in front and a foot or 
so in the back. Then you mount a fan or blower in the 
back and you have a very efficient stack robber.

The reason you don't see commercially made stack 
robbers anymore is their tendency to over cool the 
smoke causing excessive creosote and once again as with 
catalytic converters, more chimney and structure fires 
than normal.

There are a number of good ways to prevent chimney 
fires: First being a proper burning stove and well 
seasoned wood, regular maintenance is almost as 
important, sweeping, inspecting and repair.

Then there are the little details of proper use that go 
a LONG way towards never having to say you're sorry. 
Always start your fire HOT, either lots of clean dry 
kindling and a roaring blaze or pack your stove (within 
reason of course) with cardboard and light it off. The 
best way to keep from having a dangerous chimney fire 
is to have lots of SAFE chimney fires, daily is best. 
This is where starting it up with a roaring blaze comes 
in; the rapid intense temperature change causes the 
creosote to fall off before it can soften and stay 
stuck to the stack. Cardboard works really well as it's 
a processed produce and contains no creosoting 
compounds AND it burns quite hot.

Paper is a BAD choice as the vegetable inks do indeed 
contain creosoting compounds and printable paper has a 
coating of caolin clay which combines with creosote to 
form a tough asphault-like pavement. Paper also doesn't 
burn hot enough to do the job.

Next to cardboard, nearly filling your stove with small 
wood for a HOT fast blaze is best.

As to the idea you want your stove to HOLD heat. This 
is a good idea if you're living in the structure. The 
only advantage of a heat holding stove is evening out 
the temperature in the structure. Think about it; the 
whole idea behind burning wood in your shop is to get 
the latent heat from the wood into the air. The less 
heat a stove holds the faster it gets to your shop. The 
much touted soapstone stoves take forever before they 
start making the room warm, the thing that sells them 
is having the room a little warmer when you get up in 
the morning. This doesn't apply to the shop, unless 
you're in the doghouse with the spousal unit of course. 
<grin>

If you want a heat sink to help keep the shop warmer 
while you're not there they're simple enough to set up. 
I'll be heating my shop with wood, waste oil, etc. for 
the foreseeable future in a sub-arctic climate. Temps 
of -35f and lower are unremarkable around here. The 
heat sink I built for when the shop is warm enough but 
there's still fire in the stove is In-Floor heat tubes. 
I'll build a heat exchanger in the stove and circulate 
glycol through it and the floor once the air is warmed 
up a bit. I'll also be building a short version of the 
55gl drum 15gl. grease barrel stack robber for it. 
It'll pivot on the stack so I can aim the hot stream of 
air anywhere in the shop.

Another heat sink that's easy to set up though it costs 
room is an ungrouted cinder block wall behind the 
stove. You knock out portions of the bottom row of 
cinderblocks so air can circulate through it and paint 
it black to absorb radiant heat from the stove. If it's 
an outside wall you need to insulate the outside of 
course and the more the better.

The benefit of having heat sinks outside the stove is 
they don't start robbing heat till the living space 
warms up. An in stove heatsink robs heat FIRST and 
gives it back LAST. In stove heat sinks are also quite 
small. For instance the heat sink in my shop weighs 
about 60 tons. A mere 12' X 8' cinderblock wall weighs 
around 3,500 lbs. not counting the mortar.

You can enhance the properties of external heat sinks 
easily. In my case I'll circulate hot water through it, 
in the case of a hollow cinderblock wall, the addition 
of a heat tube in the stove feeding to the wall will 
make a dramatic improvement. A heat tube in a barrel 
stove is simply a 2-3" dia piece of black pipe running 
inside lengthwise near the top. Hook it to the output 
of a small blower and you can force hot air through 
your cinderblock wall.

In my experience (35 years of heating with wood off and 
on, mostly on) external heat sinks are far superior. 
The only time I put fire brick better still rammed 
fireclay in a wood stove is to protect the stove from 
premature burnout.

Andy, if you build a nice large pond within about 100' 
or so of the house so a FD pumper can supply the hoses 
your insurance will go down dramatically. There's not a 
lot you can do about the length of your driveway except 
make sure it's well maintained and always passable. The 
best bet will be to cut a second access road so there's 
little if any chance the FD equipment can get trapped 
by a fire. Most FDs will not respond to a fire if the 
men and equipment might be trapped by a fire.

Frosty
-------------------------------
If it ain't forged
it ain't real.
Wrought iron is.
The FrostWorks

Meadow Lakes, AK.

http://www.artmetalradio.com/