Heat: A Common Concern?

October 4, 2022

I’m still on the subject of heat. I imagine many of you are as well, given that the weather in the Northern Hemisphere is turning cold, and there’s this ongoing fuel crisis where it’s coldest…

We haven’t had a hard freeze here yet, but it’s been cold enough to drape frost over the fields on my drive to work. So, I’ve got the furnace going (had to do the fall servicing myself because nobody else was available… that was a fun learn-by-doing experience… thank heavens for YouTube videos!). However, the oil supplier has yet to show up and I’m not at all sure when that will happen. I’ve not lived here long enough to know their standard operating procedures. Last year I dithered around trying to avoid the whole subject until it was quite cold. I wouldn’t admit defeat and sign the contract until the end of October and so they came in November. I hope they show up before November this year because there’s much less than half a tank left over from last burning season. That probably would make it through six weeks or so, but I’d rather not test it. For one thing, I suspect that, like most fuel tanks, you don’t really get reliable flow when it’s more than three-quarters empty, and I can’t imagine the furnace will work all that well — or safely — on a stuttering fuel supply.

Which is sort of what I wanted to talk about today. Fuel supplies and how to avoid stuttering therein. I’ve spent probably way too much time thinking about burning things. And the conclusion I’ve reached is that we need more wood. And a better way to burn it…

I once sat down with pen, paper and calculator and muscled out the answer to “how big of a woodlot do I need to heat this house?”. It was not comforting. The object of the calculation was the 18th century farmhouse, which was far too large for one family, but then much of the extra square footage wasn’t wood heated. The basement was cold. The attic had one large room with electric baseboard heat and insulation; the other half was very cold and kept closed off as much as possible. (The holiday decorations were stored up there, so I couldn’t completely seal it off.) There was a summer kitchen that had been turned into an office (it was a veterinarian in former days) and it had baseboard heating too, but it also had this monster Swedish wood stove that could turn that space into an oven with just a couple logs and some kindling. It was way too much for that small space, and air did not flow from that room into the rest of the house (since that is what a summer kitchen is designed to do, isolate the heat). So I didn’t burn much back there. Nor did we use that room much in the cold season. For the most part, the wood heat was just taking care of the core of the house, or about 1800 square feet. Still big, but not enormous.

And yet, we were burning over four cords of wood a year. I’m sure the house could have been made more airtight and we might have shaved off half a cord or so. Nevertheless, I made my calculations using five cords of wood for a household. I looked up all sorts of statistics for heat generation from various kinds of wood and yields of cord-wood per acre. I think if we’d really been getting the aged hardwood that we paid for, we might have gotten more heat efficiency out of those logs and then that, too, would reduce what was necessary. But still… I stuck with the five cords. Because you’re never going to get a cord of exclusively aged hardwood. No matter how involved you are in the cutting and curing of it. Furthermore, I talked with other people, including a rather data-driven wood supplier who kept track of his own usage, and found that five cords a year was squarely average for a New England home.

The number of acres necessary was enough to stop all thought on the subject for a bit, and it certainly explained how a few thousand New England colonists deforested what was dense woodland in about one lifetime. In fact, New England went through at least two rounds of complete deforestation between the 17th and 20th centuries. The first happened by the turn of the 18th century and came about largely as a result of fueling those cavernous hearths that look so quaint in colonial inns but which were the worst possible waste of fuel ever. Most of the heat went right out the chimney, and only those people nearest the flames felt any warmth at all. The second round of deforestation was mostly the result of 19th century industry.

In any case, I figured my house would need a dedicated woodlot of at least eight acres — sixteen to twenty being more ideal in terms of management — just to generate a yield of five cords annually. Eight acres to heat about 1800 square feet. Extrapolate that to cover most of the homes in this region and you get to more acreage than all of New England…

Now, that’s eight acres, almost all of which is not harvested in any given year. So there could be more than one use of that space, but still that’s a lot of wood. Another problem was that those eight acres needed to be planted at minimum about twenty years ago to generate that yield. The trees need to be at least six inches in diameter before you can cut or coppice them, and the smaller the diameter of the trunk the less wood you get per acre. Obviously. Also, the younger trees do not yield much dense, high-energy wood. Really, to get good burn out of the wood, you want to cut trees that are a foot or more in diameter — mature trees! Now, hard wood trees do not grow fast. So I needed to buy an existing woodlot of mostly mature hardwoods and begin managing it… two decades ago — which was when I quit thinking about supplying my own house.

I now think we need to go back to communal woodlots. It should be treated as a public utility, because that’s exactly what it is. It is heat for the community. There should be a division in every community public works department that manages enough acreage of quality fuel trees to supply every household in the community. Our taxes should pay for it. Or perhaps, like many commons, work hours would pay for it. Most crucially, this is something every community in a cold region needs to be doing now! Because we didn’t do it two decades ago, like every other project that needed to be started back then…

Time was when a large estate could plant a few acres of ash and chestnut saplings and coppice them for a steady fuel supply that lasted hundreds of years. Obviously, with modern diseases and a very late start on this project, we need to tweak the species list, maybe settle for something that grows faster and is more impervious to germs. Perhaps we could start with willow and cottonwood or birch and maple — which also would give us gallons of syrup! I suspect a few standards of oak and ironwood interplanted with Osage orange and walnut would also be a good species mix, and of course oaks and walnuts give you food on top of fuel. For that matter, Asian chestnuts will grow here, and if the goal is to coppice a woodlot, not grow a natural forest, then maybe we plant them. Ash is probably hopeless for now… but still… maybe we plant a lot of saplings for the day when the bugs are gone… because ash is the best tree for just about everything…

But even that might be difficult to manage. There just isn’t enough space. So then I started thinking about the French method of centralized boilers and piped steam. It would be an expensive project, but not outrageous and almost certainly less costly than what we’re going to be spending on propping up decrepit fossil fuel infrastructure. But one boiler could supply heat to a neighborhood, with pipe laid right alongside the plumbing from municipal water lines. Radiators and radiant floor heating are not much more expensive for each household than converting a forced air heating system into wood-burning heat. And many older homes have the remnant plumbing for heating in place already. It just needs to be connected to a grid.

This would substantially reduce the fuel use. First, each burn would be heating more than one home. But then the heat is different also. A wood stove must radiate the heat into the air. This takes quite a lot of heat energy — either a really huge, hot central stove or lots of wood-burning stoves, for one in every room. But a boiler system only needs to heat the boiler. The heat is then carried in the steam throughout the plumbing delivery area. It does lose heat along the way, but if the pipes are well insulated (and perhaps made of insulating clay rather than conducting metal), most of the heat will remain until the steam hits a radiator where it is allowed to slow and cool and condense back into water.

There will still be a need for a heat source in most homes. For one thing, modern homes are just not built to conserve heat or to direct it to where we need it. Cathedral ceilings may be dramatic, but heat rises… and most of us are not tall enough to feel the warmth up there. (Now, in places where you want to shed heat, a high ceiling is fantastic, especially if it’s paired with a venting system like an air tower or a cupola. But that’s not much of a concern in places that need winter heat… ) Also, many modern homes have living spaces that are large and open. Even radiant floor heating is going to dissipate into that open space without doing much to warm up anything but your feet. If you have them on the floor. Small spaces are better for radiant heat flow, and the best flow patterns are small spaces that are stacked vertically around the heat source. Which is sort of the opposite of a standard ranch or split level American house.

But we also need heat for things like hot water and for cooking. Hot water heaters might be something we normally do with solar, supplemented with electricity, but since both of those are intermittent and stand a good chance of both being down at the same time (for instance, in a blizzard), having a small wood-burning stove would ensure that the home will have hot water for cleaning and a place to warm a pot of stew even in the worst weather. It would also ensure that there is heat in at least one room even if disaster strikes the grid. (And let’s face it, disaster will strike the grid… ) So it’s probably a good idea to plan on the community woodlot to supply more than just the community boiler. But maybe just one cord annually per household, not five. Or less depending on how sunny it is (i.e. how reliable the solar heat actually is… )

Tonight, there’s a freeze warning, so today I’m cutting what will probably be my last bouquet of zinnias and bringing in whatever fruit is hanging above ground out there. (There is actually one tomato!!!) I can leave the root veg in the ground, though there isn’t much left right now. Just the sweet potatoes and a late June sowing of carrots and beets that probably should have been pulled weeks ago, but, well… I’ve been otherwise occupied. I think the frost will do in the sweet potatoes, and I’ll be digging them over the next few days off work. The beets and carrots will come in when I get to them. They really don’t care much about cold anyway.

I’m not getting much out of this wonderful squash patch I planted and watered and weeded and generally worked hard at producing… because of the rodents… I am seriously considering tactical garden weaponry at this point. They have actually eaten none of it. They have destroyed almost everything — from a beautiful blue hubbard squash to the lumpy autumn gourds which are manifestly not food. (They don’t even smell good!) The vermin gnaw the rind into a mess of pulp and squirrel spittle and dump the poor squash disemboweled in the most prominent location possible. I think they get extra jollies if they manage to leave it where it will be stepped in. There are probably little cameras…

So I’ll be buying a pumpkin for Halloween. I suppose this is an excuse to go to the tempting pick-your-own farm on the way home from work. They advertise cider donuts… on a big sign by the side of the road… probably causes rubber-necking accidents in leaf-peeping season.

Be well and stay warm! And wherever you are, I hope you have substantially fewer squirrels in the pumpkin patch.


Photo by Nico Jacobs on Unsplash

Eliza Daley

Eliza Daley is a fiction. She is the part of me that is confident and wise, knowledgable and skilled. She is the voice that wants to be heard in this old woman who more often prefers her solitary and silent hearth. She has all my experience — as mother, musician, geologist and logician; book-seller, business-woman, and home-maker; baker, gardener, and chief bottle-washer; historian, anthropologist, philosopher, and over it all, writer. But she has not lived, is not encumbered with all the mess and emotion, and therefore she has a wonderfully fresh perspective on my life. I rather like knowing her. I do think you will as well.

Tags: home heating, managed woodlands, wood stoves