Maybe it’s just me, but it seems as though the pace of events has picked up significantly over the last few weeks. As I write these words, Libya is apparently poised on the brink of civil war, several other nations in the Middle East are facing mass uprisings, and the price of oil has soared to levels stratospheric enough that the global economy is gasping for breath – US$112 a barrel for benchmark Brent crude. For those who are keeping track, this is right around ten times what the same barrel would have brought in 1998, when today’s peak oil scene began to shake itself out of its post-Seventies hibernation.
Exactly where things will go from here is anybody’s guess, but the mostly US-backed dictatorships that have kept much of the Arab world locked in a state of sullen passivity while our SUVs burn their oil are clearly nothing like as stable as they once seemed. Soaring food and commodities prices, along with the impact of a global depression that has ended only in the imaginations of the Obama administration’s spin doctors, have shortened the fuse of popular discontent over large parts of the nonindustrial world. Those people in the industrial nations who have convinced themselves that the natural resources that support their lifestyle are conjured into being in corporate boardrooms are beginning to have to come to terms with their actual dependence on corners of the world where the comforts they take for granted are nowhere to be found.
It will be interesting to see what happens if the current round of crises turns into a full-blown energy crisis, as it well might, with oil prices spiking up past $200 or $300 a barrel, say, and the cost of gasoline and diesel fuel following the same upward trajectory until demand destruction puts a ceiling on them. No doubt there will be any number of attempts to blame it all on the oil companies, or the Arabs, or the Obama administration, or perhaps David Ickes’ imaginary space lizards; no doubt there will be at least as many proposals to rush another round of stimulus money the US government doesn’t have from the Fed’s already overworked printing presses and pour it into fusion power, cellulosic ethanol, and an assortment of other high-tech ratholes; no doubt there will be plenty of people insisting that we’d have all the energy we need if we just put the same amount of freshly printed money down some other set of ratholes. What interests me, though, is whether there will be any amount of attention, or even lip service, paid to the real alternative to petroleum.
There is one, you know. People in the contemporary industrial world rarely think about it, because our civilization is so obsessed with delusions of limitlessness that the only alternative to unlimited fossil fuels most of us can imagine is some other energy source that’s as least as abundant, convenient, and concentrated. The fact that no other energy source fits these specifications simply adds pathos to the fantasy, and motivates the sort of breezy optimism that insists that there must be some vast new source of energy waiting to be found because, basically, we want one, and will whine incessantly until we get it. Beyond the daydreams of cellulosic ethanol, algal biodiesel, and all the other attempts to insist that we can replace the value produced free of charge by half a billion years of prehistoric sunlight and geological heat and pressure with our own supposedly limitless cleverness, though, there’s a simple and relatively straightforward alternative waiting to take up the slack as petroleum goes from cheap and abundant to expensive and not nearly abundant enough.
What’s the alternative? Using a lot less energy.
The average American, it bears repeating, uses something like three times as much energy each year as the average European, to support a standard of living that by most of the usual measures isn’t nearly as high. Some of that extravagance is hardwired into the built environment of American society on a scale that individuals can’t readily change, but this is far from true of all; quite a bit is held in place by nothing more than habit and fashion, and can be changed readily, while a good deal more is built into our physical surroundings on a scale that can be changed by individual action.
It’s this latter dimension that I want to continue to address this week. Unless you live in New England, or one of a few other regions where oil-burning furnaces are still a common source of domestic heat, decreasing the amount of energy you use to heat your home won’t directly affect how well you’ll be able to weather a new oil spike. Indirectly, of course, anything that decreases the amount you have to pay out for one kind of energy will free up money for other uses; furthermore, as the price of petroleum continues to rise relative to natural gas, coal, and other energy sources, it’s a safe bet that other fuels will be used to substitute for petroleum in one way or another – there are already plenty of cars and buses that burn compressed natural gas, for example, and electric cars (running, of course, on electricity that’s mostly produced by burning natural gas or coal) are also beginning to hit the market.
Factor these conversions into the likely future price of natural gas and coal- or natural gas-fired electricity, and a petroleum price spike risks setting off a broader energy crisis, just as it did in the 1970s. The cost of home heating is as vulnerable to this knock-on effect as any other kind of energy use, and being able to make a given amount of heat go further becomes a crucial strategy.
With this in mind, it’s time to talk about insulation.
Most American homes leak heat like sieves. Part of that, as discussed last week, is a function of the fact that most American homes leak air like sieves, and as cold air leaks into your house and warm air leaks out of it, a portion of your heat bill goes for warming the great outdoors by some tiny fraction of a degree. Part of it, though, is a function of the fact that the ceilings, walls, and floors of most American homes offer inadequate resistance to the flow of heat. Put your hand flat against the inner surface of one of your home’s exterior walls some cold winter night; if the wall feels colder than the inside air – and in a lot of American homes these days, it will – you’re feeling the result of low resistance to heat flow.
Resistance to heat flow is measured by what, usefully enough, are called R-values. Every material has its own R-value, and the R-value of most construction materials isn’t very high – a half-inch thick sheet of plywood, for example, has an R-value around 0.62, which is actually less than the R-value of the thin layer of air that clings to the inside surface of each wall of your house. A wall of standard frame construction, without insulation, has an R-value averaging around 4.25. Insulate the same wall with a roll of standard glass-fiber insulation, and its R-value goes up to an average around 12.75, which means that heat takes three times as long to flow through it.
Putting insulation inside a wall can be a complicated operation if the wall is already built, though, and I’ve heard very mixed reports on the kinds of insulation that are pumped into an already-built wall through holes drilled for the purpose. Since this blog is focusing on retrofitting and other measures on a budget, you’ll want to consider this only if you’re already planning on ripping out the drywall or replacing the siding – there are rigid board insulation products you can put on the outside of your house, between the old sheathing and the new siding, with good results. You can also borrow a trick from the Middle Ages and use fabric hangings of various kinds to insulate your walls; we’ll discuss those in more detail next week.
If you don’t have major domestic surgery or fabric hangings in mind, though, your best options lie elsewhere. The first is right above your head. Heat rises, of course, and so most houses lose a great deal of heat through the ceiling and roof; walk around the neighborhood on a day after there’s been light snow, an inch or so, and you can often see a dramatic difference between the parts of roofs that have heated space beneath them and the parts that don’t, evidence of the amount of heat rising up into the atmosphere. In most cases, the best place to put your insulation is right above the ceiling of your upper floor (if you have more than one), working from the attic, and you want a lot of it – an R-value of 60 is not excessive in a cold climate. The reason you want to have the insulation just above the ceiling is threefold. First, since heat rises, you want as much as possible of it to stop rising while it’s still in your living space, rather than warming the cobwebs in the attic; second, your attic can then be vented, and if you live in a snowy area this will keep the roof cold and prevent the freeze-thaw cycles that generate ice dams along the eaves and potential repair bills in three or four figures; third, if you live in an area with hot summers, a vented attic and good insulation means that the solar heat that builds up under your roof can be vented out into the outside, while the insulation keeps it from trickling down and making your living space miserable in August.
If you have an unheated air space underneath the first floor, whether it’s a basement or a crawlspace, that’s another good area to insulate. Here your insulation should go right up under the floor, and you normally do this from underneath. Insulation with an R-factor of 19 or so is usually enough to keep the cold from creeping in. In most cases, if you caulk, weatherstrip, and insulate above the ceiling and under the floor, you’ll cut your annual heating bills by up to half, using your own unskilled labor and supplies your local hardware store will be happy to sell you. The one further step to add to the package is insulated window coverings, which we’ll be discussing next week – they provide a huge gain, since your ordinary single-pane window has an R-value around 1, but they’re complex enough to require a post of their own.
There’s a complicating factor with insulation, though, and that’s the effect of water vapor. The amount of water vapor that can be carried by a given amount of air depends on the temperature of the air, and as the temperature drops, the vapor turns back into liquid water and condenses onto any available surface. That’s where the drops on the outside of a bottle of cold beer come from – the air close to the bottle becomes chilled, and the water vapor contained in the air condenses out onto the glass. When it’s cold outside and warm indoors, you get a similar temperature drop in the middle of an insulated wall, and any water vapor that’s present will condense out onto your insulation. Water conducts heat much better than insulation does, so that condensed water causes a sharp decrease in the R-value of your insulation, and it can also lead to problems with mildew and dry rot in extreme cases.
You prevent this with vapor barriers. The standard vapor barrier these days, I’m sorry to say, is plastic sheeting, which is waterproof, moldproof, airtight, and cheap; finding a way to make something comparable from renewable materials would be a very worthwhile project. In the meantime, though, you need a vapor barrier if you’re going to insulate, and that means plastic sheeting, well overlapped and taped with duct tape. A crucial point you need to remember is that the vapor barrier always goes on the side of the insulation that’s going to be warmer – in other words, when you’re insulating the ceiling from the attic side, or the floor from the basement or crawlspace, the barrier goes in first and the insulation afterwards, but if you’ve torn out some drywall and are installing insulation, the insulation goes in first and the vapor barrier goes on over it, right beneath the new drywall.
Here again, if you have the money to spend, you can insulate the living bejesus out of a house and get it to the point that body heat, cooking, and a bit of additional boost on really cold days will take care of your heating needs. The Passive House system mentioned in last week’s post uses this as one of its ingredients, and it’s certainly an option, but it’s going to set you back a chunk of change. Those who don’t have that kind of money to spare – and they will likely be the very large minority over the decades to come – can still keep themselves, their families, and anybody willing to learn from them comfortably warm in winter on much less energy by using the simpler methods discussed here. Further on down the curve of the Long Descent, as current housing stock wears out, other techniques will need to evolve; with any luck, enough knowledge of how insulation works can be passed on through the upcoming crises to make that process easier than it would otherwise be.
It’s probably necessary to reiterate here that insulating your home is not going to save the world. For that matter, insulating all the homes in America won’t save the world, and that probably can’t be managed at this point anyway, if only because most Americans have gotten so tipsy on the fantasy of infinite energy that only a fairly modest fraction of the population is likely to be willing to put in the modest amount of labor and money needed to do the thing. Still, as I’ve suggested tolerably often in these posts, we are long past the point where any sort of grand organized project to stave off the Long Descent could still be carried out with any hope of success, even if the resource surplus still existed and the political will could be mustered. The window has closed, the surpluses are gone, and the political will to accomplish much of anything but handwaving and hunting for scapegoats went AWOL a long time ago; what remains is the hard but potentially rewarding project of adapting to a challenging future, and to that, simple steps such as home insulation have much to offer.
Here again, the best place to start is with the Master Conserver worksheets available online at the Cultural Conservers Foundation website; the papers you want are the ones titled "Home Insulation" and "Reducing Moisture Problems." Beyond that, just about any handbook on home repair and maintenance published in America from the 1960s onwards includes a section on how to install the usual kinds of insulation. Larry Gay’s The Complete Book of Insulating is a good reference for those who want to go the extra step or two.