By Lambert Strether of Corrente.
My father’s reaction to the oil crisis of 1973 was to install two wood stoves, both downstairs in the enormous house I later came to inhabit. The house had at one point been heated by coal, but the hulking and decaying boiler in the basement had long ago been converted to oil[1]. Back in the day, the day when taking in a grad student would pay the fuel bill for the winter, oil was ten cents a gallon, and the house thermostat was, naturally, placed near the front door, so the draft when somebody entered would turn on the boiler, making everything toasty (after about 45 minutes when the steam[2] reached the radiators).
After the oil crisis, this fueling protocol was no longer tenable. My father forbade entering the front door — the house had rather a lot of doors, so we used other ones — installed the Jotul stoves, and purchased a woodlot so he could cut and split his own wood. At night, he set the stoves going, turned the thermostat down to 50 degrees, and piled on the blankets.
Time passed, and I came to inhabit the house during the oil shock of 2007–2008. Clearly, my father’s fueling protocol was no longer tenable, and decisions had to be made. Hoisting my own comment in response to alert reader Larry Carlson:
Parts of the house are 100 years old; others are from the 40s (I think). The house is quite large.
The project took several years.
1) Fill in the attic, first.
2) Insulated windows (eliminating the rattling wood frames)
3) I did a lot of sealing around doors, interior and exterior (stuff I could buy at the hardware store). I also created a routine of covering the windows with plastic wrap in the winter (even the insulated ones). I also piled garbage bags of raked leaves around the exposed part of the basement walls. Both these last measures were really helpful, both for the perception of heat and drafts.
After a pause I found another vendor who started by doing a blower door test; the house still pinned the meter (!);
4) On top of the attic fill, pink stuff (nothing on the roof because we want the attic cool).
5) Basement and large crawlspace foamed (can’t say it was 4″ but I whatever the standard was, it was that). Plastic on the floor of the crawlspace.
The house is not tight enough to require an air exchanger, but it did pass the blower door test.
6) In addition, since one object was to save on fuel, I installed a new (and efficient) natural gas furnace to replace a monstrous old oil burner.
It was quite a project!
The new boiler was the endpoint of the project, and so for a good decade I lived with a wood stove. At some point, the two Jotuls had been abandoned and replaced by a single no-name black steel box in the room where I had come to live. The steel box was extremely rugged and simple not to say primitive: You controlled the draft, which in turn controlled the amount of oxygen reaching the fire inside, with two valves that you screwed open or shut. To “turn off” the stove, you screwed both valves shut. For a roaring blaze, you opened them all the way. That was it. For me, the important thing about a wood stove is that the quality of the heat is like no other. If you want to feel like this cat, buy a wood stove.
There is something about the way that a wood stove with a solid, long-lasting fire radiates heat that is highly conducive to relaxation or sleep. I can’t explain it, but for me it is true. (The issue is the thermal mass of the stove, present whether the stove be steel, cast iron, or soapstone.) The heat from a wood stove is amazingly comforting.
But of course this isn’t about our feelings[3]. I should say that the picture above is a little deceptive and my own set-up was[3] pretty different. First, I deplore the decorative aspects of the stove; the window, the legs, the unboxiness. Second, that stack of wood at the left is way too neat; was it bought wrapped in plastic at 7-11 or what? Third, my stove was set on a steel plate, the steel plate rested on a wood floor, and a black metal sheet-metal pipe rose from the back of the stove, took a turn to the horizontal, and joined itself to a brick chimney by cutting through a wall to which the pipe and the stove were both far too close. (Contrast the neatnik’s arrangement of bricks in the photo.) Fourth, since I lived in the same room as the stove, there were a lot of books and papers scattered about, along with computer equipment, plus chips and bark from carrying the wood in. In other words, the stove in the photo is safe. My stove was, in retrospect, a ridiculous, albeit grandfathered, fire hazard. Don’t be like me!
So much for the stove. Now for the wood! (I admit at the outset I did not think through a fueling protocol. You probably should. I went with what I already knew, plus advice from other owners.)
As coal comes in tons and linen in yards, wood comes in “cords” (normally cut to a length appropriate for your stove, itself of a standardized size):
A cord is the amount of wood that, when “racked and ” (arranged so pieces are aligned, parallel, touching and compact), occupies a volume of 128 cubic feet (3.62 m3).[1] This corresponds to a woodpile 4 feet (122 cm) high, 8 feet (244 cm) wide, and 4 feet (122 cm) deep; or any other arrangement of linear measurements that yields the same volume…. Maine appears unique among U.S. states by also defining a “ cord” or of cut firewood: “A cord of 12 or 16 inches (30 or 41 cm) in length shall mean the amount of wood, bark and contained in a space of 180 cubic feet (5.1 m3); and a cord of wood 24 inches (61 cm) in length shall mean the amount of wood, bark and air contained in a space of 195 cubic feet (5.5 m3). [1981, c. 219 (amd).]” Other non-official terms for firewood volume include standing cord, kitchen cord, running cord, face cord, fencing cord, country cord, long cord, and rick, all subject to . These are usually taken to mean a pile of wood in which the logs are shorter or longer than in a legal cord, to accommodate various burners.
So you can see from the helpfully underlined verbiage that — unless you own your own woodlot — what an actual cord is depends very much on your vendor, and so you should find a reliable one. How much to buy? Unless you’ve done your homework and calculated your likely consumption in a fueling protocol, I would ask the vendor (and maybe order a little too much, for a reserve).
Wood is either “seasoned” or “green.” Seasoned wood has been cut down and left to dry out for at least, well, a season. Green wood is sold in the same year it is cut. Seasoned wood is more expensive than green, but not, at least when I was buying it for the land ship of a house, killingly so. More importantly, green wood is full of sap and moisture, which means it burns inefficiently and creates the by-products of incomplete combustion, like carbon monoxide and creosote (gunk that coats the inside of your chimney and in sufficient quantity is a fire hazard). But if you have just installed your stove this year, you may need to buy green wood: Half for this year, and half for next year, by which time it will be seasoned. Of course, in a perfect world you would buy seasoned for this year, and green for next (assuming you have space under a roof somewhere to stack and store it), and then green ad infinitum.
Wood is sold split or not. My father found that splitting wood was good exercise; I went so far as to purchase an axe, but ultimately felt that the risk of losing an ankle out of clumsiness was too great a risk.
Wood is also “hard wood” or “soft wood.” Hardwoods are (for example) oak, ash, or maple. Softwoods are pine, spruce, larch, cedar (and pine is pretty bad wood, IIRC). Softwood burns easily and fast, and so produces little heat (that is, the thermal mass of the stove doesn’t have much to soak up). Hardwood burns hot and long, but ramps up slowly. Softwood is cheaper than hardwood. So, you need to decide on a mix or ratio of hardwood to softwood (and frankly, I forget what mine was, except that it was mostly hardwood; ask your vendor[4]). There is also birch, a hardwood that burns like softwood. I always bought a little birch, because starting a fire with birchbark is much, much more pleasant than starting it with newspaper (which burns ink and other horrid substances, and I don’t care that the inks aren’t oil-based anymore).
There are buyers guides for wood stoves (here, here) but I’m not going to go into how to actually buy a wood stove; your situation is as unique as your dwelling space. I will, however, go through a number of issues, some essential, some ancillary, that are not covered in buyers guides. Here are some things to think about.
Essentials–
1) Code enforcement. Before installing a wood stove, you should check with your local code enforcement office to see what their requirements for a wood stove are; as you have seen, my wood stove was totally not up to code; I was lucky to get away with it, or I was protected by a benevolent fate. Items that code enforcement might be concerned about include the surface on which the stove rests, the distance from walls, smoke detectors, and so forth.
2) Emissions. For those inclined to do homework, this issue of Journal of the Air & Waste Management Association looks really good, and the articles are unlocked (at least as of this writing). From “Introduction to Special Issue on Residential Wood Combustion“:
Wood heating, as a renewable energy source, is viewed by many as an environmentally beneficial, “green” heating option. From a pollution perspective, . In many states throughout the country, residential wood heating is one of the largest sources of PM. High wood combustion emissions have resulted in rural regions with elevated PM2.5 including some that are in non-attainment. Yet in areas without attainment issues, wood heating has not met with the same level of concern as other sources emitting far less criteria and air toxic pollution. As emissions decrease from industrial and electrical generation units, emissions from area sources, such as residential wood heating, represent opportunities to realize significant emission reductions and achieve public health goals in the coming decades.
Now, I never had to think about any of this; it was sufficient for me that I wasn’t burning oil. So I am by no means an expert. First, I am guessing the key is complete combustion, both for the particulate and the carbon monoxide. Second, everything should go up the flue, meaning that neither PM2.5 nor carbon monoxide should be concern inside the house (assuming your chimney is sound). Interestingly, your Corsi-Rosenthal box that takes care of Covid should take care of PM2.5. However, what goes up the flue matters, bringing me to–
4) Catalytic converters. From Inspectapedia:
The operating concept of a wood stove combustor is the same as that familiar to readers whose automobile uses a catalytic converter to clean up their vehicle’s exhaust. Catalysis is defined as the speeding-up of a chemical reaction by using a catalyst – an additive or agent whose presence speeds up a chemical reaction.
In a woodstove catalytic combustor, smoke and hot gases from burning firewood pass through a honeycomb of material coated with platinum/palladium that, at sufficient temperature, break down the components of the smoke into less harmful end products, ideally, or in perfect operation, producing simply carbon dioxide (CO2) and water (H2O)
The platinum or palladium (both may be present) are the catalysts. The honeycomb design provides sufficient surface area to treat the volume of exhaust passing through the combustor. High temperature is necessary for the catalytic process to occur.
The temperature rage at which a catalytic combustor in a woodstove can work varies among specific catalytic combustor products and among wood stoves, but typically the device can operate as low as 250°F (121°C)in some designs, but more often at a higher temperature, between 400°F (240°C) and 500°F (260°C).
To protect the combustor from damage or clogging with creosote and ash, the woodstove will include either a manual or an automatic control to bypass the catalytic device when the stove is not at sufficient operating temperature.
Again, this advanced technology was not present in my day; but it does seem that a fueling protocol that heats the fire fast is important to absolutely minimize the length of time the catalytic converter is bootstrapping. And:
Catalytic stoves are typically more expensive long term than non-catalytic models because the catalyst honeycomb eventually breaks down and needs to be replaced. Modern catalysts can last up to 10 years with proper maintenance and use.
Non-catalytic or secondary combustion stoves make up about 80% of the market. They tend to be less expensive and have an average efficiency of 71% (with a range of 60-80%). Modern model design improvements like firebox insulation, a large baffle to produce a longer hotter gas flow path, and pre-heated combustion air which comes through small holes above the fuel in the firebox create lower emissions. The actual fire and the flames are generally more visible compared to a catalytic stove. Non-catalytic stoves are simpler to operate, and don’t require catalyst maintenance or cleaning.
I like very much the idea of minimizing emissions through the design of the stove itself, rather than with a complicated add-on with its own emission issues. But I do think a catalytic converter is something to be seriously considered even for a well-designed stove. (Also, catalytic converters are sold as add-ons, so depending on the configuration of your stovepipe, I don’t see why a requirement for a converter need affect your choice of stove. In fact, an add-on is probably better, because you can upgrade it without buying a whole new stove.)
3) Chimney. If your stovepipe vents into a chimney, find a reliable chimney sweep and have them clean your chimney before heating season.
Here are three ancillary products not visible in the photo–
5) Fan. You can put a fan on top of your stove to distribute heat more evenly throughout your dwelling:
A heat powered fan sits on top of the wood stove and as the stove comes up to temperature the fan blades start spinning. Some manufacturers claim that a heat powered fan pushing warm air away from a wood stove will help heat a room up to 18% faster.
The other benefit of a heat powered fan is that by moving air around (and creating a convection effect), the wood stove does not have to run as hot and therefore you can use less wood.
There are two common types of heat powered wood stove fan designs, a Thermoelectric Generator which is an electrical design, and a Stirling Engine which is a mechanical design. Both heat powered fan designs work by exposure to temperature differences, where one part is exposed to warmth (as per a wood burning stove), and the other part is kept cooler.
I wish I had known about stove fans; obviously, I would have purchased a mechanical design. Here is a Buyer’s guide.
6) Bellows. For a long time, I would start a fire by raking last night’s ash and coals level, then piling birch and small sticks or wedges of wood over birch bark. Then I would light the birch bark with a wooden kitchen match — one match, naturally, Boy Scout-like — and then blow on the pile until it caught, and the softwood on top of the pile began to catch. (Then I would shut the stove door, and open the valves all the way. When the softwood was roaring, I would open the door, pile on the hardwood, and after a short time close the valves almost completely. Then, after a short while, the soft, lovely, lovely radiant heat would begin. But I digress.) Well, kneeling down and puffing and wheezing got unpleasant over time, and I had the bright thought of getting a bellows. The bellows were great; much more powerful and efficient than my own breath. And now, I learn, since getting the fire hot fast is important for emissions control, civic minded as well. So I highly recommend bellows.
7) General mess. I am not strong on housework. Carrying wood in from wherever it’s been stored leaves a trail of wood chips, dust, twigs, little bits of bark, not to mention tromping in snow and ice. I am at best an indifferent housekeeper, so it never did occur to me to buy a small shop vacuum to clean up the matter left behind after each run for wood. And then, of course, there’s cleaning out the ashes (scuttle to the right in the photo) and hauling them. Something to consider.
Dear reader, I don’t want to scare you off; it does seem, however, that a wood stove is more of a companion than a boiler or a heat pump[5], and also more integrated into a local community (which is in my view good). Although I have gone into a lot of detail in this post, in practice my wood stove gave a wonderful quality of heat, was easy to operate once I learned its ways, was extremely reliable, and didn’t take a lot of time; firing it up was simply a daily ritual that I did without a lot of fuss. I encourage those of you aghast at high fuel prices to look into them. Wood stoves are also possibly the most Jackpot-compliant home-heating method there is, so if you plan to remain in the same patch for more than ten or twenty years, you might consider looking into one now.
NOTES
[1] Oil is a horridly noxious corrosive substance best left in the ground under taboo, as I discovered the few times I had to fill a five-gallon plastic jerry can at the truck stop and then tromp through the snow to top up the tank with it, when the oil delivery man was late, or the weather colder than I had thought.
[2] I stan for steam (and not hot water). Steam is extremely simple and rugged, which is my kind of engineering. For those new to steam heat, or struggling with it, I highly recommend Dan Holohan’s We Got Steam Heat. Interestingly, many steam heating systems are, to modern sensibilities, overspecified; they can get so warm you can leave the windows open. That was, in fact, by design: Open windows during the winter were a measure taken against airborne pandemics.
[3] Why did I get rid of the wood stove if I loved it so much? Partly because it wasn’t up to code, partly because my life had become busier, and I didn’t want to spend time managing my fueling protocol manually. However, I believed I was past the oil crisis, too. Oops.
[4] Be careful about this, because this is one way a woodseller can, as it were, take you, without actually cheating you. “You never said!”
[5] Heat pumps are complicated. No thanks.
