[TheForge] Wood Stove for Shop heat

[Peter Fels And Phoebe Palmer]

Great exposition Frosty, thanks for straightening me out on the 
catalytics...pf

Jerry Frost wrote:
> 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
>