Affordable Housing Institute : US

What’s the best way to manage a home’s indoor climate?

 

 

As I type this blog post, our house’s fan is running behind me, circulating air – and directly in front of me is a lovely bank of fifteen-light windows through which I can see our back garden.

 

Why don’t I just turn off the fan and open the windows?

 

Wonder what my energy loss rate is?

 

Throughout history, people have craved windows in their dwellings – for air, for light, and for view.  Windows let in bugs and water.  They also leak heat out and cold in, or vice versa. 

 

And into the basement …

 

That’s why, for the last fifty years, the trend in evolving modern buildings (homes and otherwise) has been to seal the building’s airflow even as we increase its overall transparency.  

 

Is that wise? 

 

Windows are the bane of a homeowner’s existence – and even more the bane of a landlord’s existence.  They’re surprisingly expensive to make, assemble, and install.  If movable, they’re a fairly complicated installation that rattles and usually leaks.  Painting the window trim is a bitch. 

 

It’s a bitch of a job

 

For all these reasons, modern buildings have windows you cannot open.  In previous posts, I’ve talked about the architects’ tendency to design complicated structures, which tend to leak, or have unexpected consequences.  Via reader Matthew Healy, that led me to building airflow expert Tim Padfield and his paper, The Window in Context:

 

Abstract.  The ventilation requirement for a house is a compromise between the need to keep the indoor relative humidity down and the need to minimize energy consumption. 

 

* The first requirement is itself a short-circuited train of reasoning about how to prevent condensation in the structure with consequent mould growth. 

* The second requirement was until recently defined as the permitted energy used to keep the occupants physically comfortable.

 

Aside from being unsightly, mold is extremely toxic of a small subset of people, and that means litigation, lawyers, and money.

 

Got a little problem, have we?

 

Mould growth in the occupied part of the house is only indirectly a consequence of high indoor relative humidity- it is usually a consequence of uneven wall temperature gradients within the structure. 

 

I never knew that – it’s not the humidity by itself, but rather how temperature changes within a structure, because with a wide temperature gradient, somewhere is an environment that allows mold to grow.

 

Designing a structure that is robust enough to be badly built and intermittently maintained is just as important to the life cycle costs as is the energy consumption from day to day.

 

I absolutely love that line, for it’s the reality – maintenance is imperfect.  In Tthe risk of complicated structures, I’ve previously quoted Padfield’s Law of Construction:

 

 

Trends in building design have been towards complicated, lights structures optimized through the use of computer models but not always performing as expected when released into the care of the occupants.  In particular the intricate detailing and tendency to use non-water-absorbent materials brings considerable risk of condensation in the northern European climate, with subsequent mould growth.  Air barriers have not provided the expected security from condensation within the outer envelope of buildings.

 

We saw that in dreamers versus plumbers.  Then there’s this admission:

 

There are some rather fundamental holes in our knowledge of the dynamics of biological growth. In particular the ecology of microorganisms has been relatively neglected in favour of experiments based on sterile media inoculated with purified organisms in a constant environment.  The influence of air flow and air exchange on growth has been neglected.

 

It’s imaginative, but it’s not the world

 

Just as Korzybski said the map is not the territory, the model is not the reality. 

 

“This is not a pipe”

 

In finance, we love our models, but the word ‘model’ implies approximation, not the full complexity of reality.  Some things are hard to model, so we omit them – and sometimes that’s a mistake.  And when I hear phrases like “not well understood,” my mind immediately drifts to “tort litigation” and then “expert testimony” and even something called the “Daubert standard.”  Wikipedia’s summary is quite good:

 

In Daubert, the Supreme Court held that federal trial judges are the “gatekeepers” of scientific evidence. Under the Daubert standard, therefore, trial judges must evaluate proffered expert witnesses to determine whether their testimony is both “relevant” and “reliable”, a two-pronged test of admissibility.

 

And the UFO’s light were right along here …

 

The relevancy prong: The relevancy of a testimony refers to whether or not the expert’s evidence “fits” the facts of the case. For example, you may invite an astronomer to tell the jury if it had been a full moon on the night of a crime. However, the astronomer would not be allowed to testify if the fact that the moon was full was not relevant to the issue at hand in the trial.

 

The full moon had nothing to do with it

 

The reliability prong: The Supreme Court explained that in order for expert testimony to be considered reliable, the expert must have derived his or her conclusions from the scientific method (Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993) 509 U.S. 579, 589.) The Court offered “general observations” of whether proffered evidence was based on the scientific method, although the list was not intended to be used as an exacting checklist:

 

* Empirical testing: the theory or technique must be falsifiable, refutable, and testable.

* Subjected to peer review and publication.

* Known or potential error rate and the existence and maintenance of standards concerning its operation.

* Whether the theory and technique is generally accepted by a relevant scientific community.

 

With illness due to mold rising as a source of class-action litigation and tort liability to owners, the cause of mold growth can be a multi-million-dollar issue.

 

The movement of water in hygroscopic materials is not understood, to judge by the failure at the many models to account convincingly for water and dissolved salt movements in porous materials and their difficulty in dealing with lateral irregularities in real walls. 

 

Water runs along cracks.

 

Water leak inside a ceiling (not Photoshopped!)

 

There is continued reliance on mathematical analogy between heat and material transport through porous materials, even though the movement of water molecules through the mesh of different sized pores is unlikely to be purely diffusive phenomenon.

 

The erratic ventilation caused by undisciplined use of windows is a considerable further inconvenience for these modelers. 

 

Programmers and economists tend to ignore what we cannot model, and of these things we wish to ignore, human behavior is among the most complex. 

 

It is perhaps easier to believe that one has control when all the windows are sealed shut and a computer controlled ventilation system is installed, but experience does not always support this conviction. 

 

People, bless their illogical hearts, do odd things; sometimes the wrong thing, sometimes the right thing.  Can we construct incentives to do the right thing?  Why, yes, we can – individual metering is the most basic example.  Further, people are observant: recent pilots that have installed usage meters in houses – or hooked them up to computer monitors – have shown that people reduce their energy use when they can see where it comes from.

 

These material investigations, together with physiological studies of people’s tolerance to draughts and uneven temperature indoors, promise to re-activate the discussion on the use of traditional ventilation through windows as a perfectly reasonable way to control to indoor climate without unreasonable waste energy. (Pg. 2)

 

In other words, the biological thermostat might just be better than the mechanical or electronic ones.

 

One way to keep the temperature where you want it

 

Another approach

 

If houses could be designed to work well with windows that are opened when it is convenient for the occupier, one could minimise energy loss and unpleasant draughts. For example, a bedroom with water absorbent and carbon dioxide permeable walls will hold a good microclimate throughout one night with windows closed. The windows can be opened for a short period during the day to regenerate the buffer capacity of the wall.

 

That morning sense of needing fresh air isn’t your imagination. the air does need recirculation.

 

This is also the time when the ambient temperature is highest, so the energy loss is less than if the windows were slightly open all night to ventilate away moisture and carbon dioxide. (Pg. 37)

 

When I was kid, you were supposed to sleep with a window open, even when it was cold.  Maybe they knew what they were doing.

 

If only I could open windows too

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Yesterday’s post, taking as its source text a lengthy and thoughtful essay by Alan Ehrenhalt in The New Republic, followed the enrichment of cities as the world urbanizes in this century of cities.

With wealth come other benefits.  Wealthy cities are cleaner.  They are also safer:

 

Nor, in general, does the scourge of urban life in the 1970s and ’80s: random street violence. True, the murder rates in cities like Chicago, Philadelphia, and Cleveland have climbed in the last few years, but this increase has been propelled in large part by gang- and drug-related violence.

 

For the most part, middle-class people of all colors began to feel safe on the streets of urban America in the 1990s, and they still feel that way. The paralyzing fear that anyone of middle age can still recall vividly from the 1970s – that the shadowy figure passing by on a dark city street at night stands a good chance of being a mugger – is rare these days, and almost nonexistent among young people.

 

When I came to Cambridge, in 1971, we were warned not to cross Cambridge Common at night.  Now, Cambridge Common, which isn’t that large a park, nor that far from the streets.

 

Cambridge Common, 1808: where George Washington first mustered the Continental Army

 

Cambridge Common, 2008: once again safe

 

Today we think nothing of it.  Partly that’s technology – sodium lights give so much more night-time illumination – but mostly it’s lower crime rates.

 

Walk around the neighborhood of 14th and U streets in Washington, D.C. on a Saturday night, and you will find it perhaps the liveliest part of the city, at least for those under 25. This is a neighborhood where the riots of 1968 left physical scars that still have not disappeared, and where outsiders were afraid to venture for more than 30 years.

 

When I first came to Washington on business, 14th and U was a part of the city you did not go.

 

The man who wasn’t mentally there: Chauncey Gardner

 

The young newcomers who have rejuvenated 14th and U believe that this recovering slum is the sort of place where they want to spend time and, increasingly, where they want to live.

 

I’m struck by the phrase ‘recovering slum.’  A slum dies, as I wrote before, out of a combination of private enterprise, public investment, and social reform:

 

Even in their times, the Victorians’ self-important righteousness made them objects of derision by such exquisite critics as Lytton Strachey (in his surgically slim volume, Eminent Victorians) and A. N. Wilson (The Victorians), but for all that they present a morally inflated target for the puncturing quill, they were the great altruists who changed how we think of the duties the rich and powerful have to those poor and powerless.  So it was with the Victorian slum; it was not allowed to wither away, it was attacked on multiple fronts by multiple crusaders:

 

By now, cities have become cool:

 

This is the generation that grew up watching “Seinfeld,” “Friends,” and “Sex and the City,” mostly from the comfort of suburban sofas. We have gone from a sitcom world defined by “Leave It to Beaver” and “Father Knows Best” to one that offers a whole range of urban experiences and enticements. I do not claim that a handful of TV shows has somehow produced a new urbanist generation, but it is striking how pervasive the pro-city sensibility is within this generation, particularly among its elite.

 

Television is usually ahead of the zeitgeist, but not very far ahead.  As people become able to earn more, an hour of time has a high opportunity cost, leading to a changed equation about the relative appeal of living in the suburbs and the city:

 

Not that cars and the demographic inversion aren’t closely related; they are. In Atlanta, where the middle-class return to the city is occurring with more suddenness than perhaps anywhere in the United States, the most frequently cited reason is traffic. People who did not object to a 20-mile commute from the suburbs a decade ago are objecting to it now in part because the same commute takes quite a bit longer.

 

We have only to look to the global south – Mumbai, Cairo, and Sao Paulo, to name three cities in whose traffic I’ve had the experience of sitting – to see that whatever the energy costs, commute times will only get worse. 

 

Ultimately, though, the current inversion is less the result of middle-aged people changing their minds than of young adults expressing different values, habits, and living preferences than their parents. The demographic changes that have taken place in America over the past generation–the increased propensity to remain single, the rise of cohabitation, the much later age at first marriage for those who do marry, the smaller size of families for those who have children, and, at the other end, the rapidly growing number of healthy and active adults in their sixties, seventies, and eighties–have combined virtually all of the significant elements that make a demographic inversion not only possible but likely.

 

As human beings live longer, we have stretched out our lives.  We used to marry at twenty, be grandparents by forty-five, and be elderly at sixty.  Try telling a wrinkle-defying boomer that sixty’s old age, and be prepared to duck.

 

You talkin’ to me?

You talkin’ to me?

‘Cause I don’t see any other sixty—five year-olds here

 

We are moving toward a society in which millions of people with substantial earning power or ample savings can live wherever they want, and many will choose central cities over distant suburbs.

 

In a world where money is information rather than gelt, and information is value which can be transmitted electronically (think software, or call centers, or designs).  As Rakesh Mohan, deputy governor of the reserve bank of India, put it at Bellagio:

 

With increasing free trade in services, the price of traded products has almost stabilized across the world.  Goods now have very similar prices everywhere; therefore, no city has any advantage over any other in traded goods.  Comparative advantage of nations will increasingly lie in the relative efficiency of their cities.

 

Cities have to clean up their act, to capture the highly educated high-earners who can live and work in many places.  I think this is the idea behind Richard Florida’s Rise of the Creative Class theory that if you attract the latte-drinkers, your city will grow rich.

 

The fervor of a believer: Richard Florida

 

The reality of demographic inversion strikes me every time I return to Chicago, the city in which I was born and grew up. My grandfather arrived there in 1889, found his way to the Near West Side, and opened a tailor shop that remained in business for 50 years. During that time, the neighborhood was a compact and somewhat culturally isolated enclave of Jewish and Italian families. (It was also the location of Hull House and the original home of the Chicago Cubs.) The building that housed my grandfather’s store was torn down in the 1960s when the University of Illinois built its Chicago campus in the neighborhood. The street corner where the store stood now houses part of the university science complex.

 

The UIC campus is, to my eyes, one of the ugliest in America.

 

Ugly in the eyes of the beholder: the University of Illinois-Chicago campus (foreground)

 

But I have made my peace with that. What interests me is what is going on all around that neighborhood, now called University Village. For a while after the school was built, its environs were a sort of residential no-man’s-land, dangerous at night and unattractive to the young academics who taught there. Today, assistant professors at UIC generally don’t live there either, but for a different reason: They can’t afford it. Demand for the townhouses and condominiums on the Near West Side has priced junior faculty out of the market. One can walk a couple of blocks down the street from where my grandfather’s shop once stood and order a steak for $24.

 

You might respond that there is nothing especially noteworthy in this. A college setting, liberal academics, houses close to the city’s cultural attractions: That’s garden-variety gentrification. What else would you expect?

 

Even more striking than UIC is the University of Chicago on the South Side. 

 

A little patch of green on the South Side: U Chicago

 

In the mid-1970s, and even through the 1980s, the area two blocks west of UC’s Potemkin Village was an urban war zone.  Not any more.  What’s done it?  Money, urbanizing wealth, and the demands urbanizing wealth has placed on municipal government.

 

Of course, demographic inversion cannot be a one-way street. If some people are coming inside, some people have to be going out. And so they are–in Chicago as in much of the rest of the country. During the past ten years, with relatively little fanfare and surprisingly little press attention, the great high-rise public housing projects that defined squalor in urban America for half a century have essentially disappeared.

 

Relatively little fanfare?  I guess that all depends on who you listen to.  I’ve previously posted at length about the deconcentration of poverty – which is indubitably a good thing – and the concomitant dispersal of crime – a bad but correctible thing.

 

In Chicago, the infamous Robert Taylor Homes are gone, and the equally infamous Cabrini-Green is all but gone. This has meant the removal of tens of thousands of people, who have taken their Section 8 federal housing subsidies and moved to struggling African American neighborhoods elsewhere in the city. Some have moved to the city’s southern suburbs–small suburbs such as Dixmoor, Robbins, and Harvey, which have been among the poorest communities in metropolitan Chicago. At the same time, tens of thousands of immigrants are coming to Chicago every year, mostly from various parts of Latin America. Where are they settling? Not in University Village. Some in Logan Square, but fewer every year. They are living in suburban or exurban territory that, until a decade ago, was almost exclusively English-speaking, middle-class, and white.

 

Movement does not ipso facto change wealth.  It should be obvious, therefore, that if some rich displace some poor, the poor will go elsewhere – unless we build affordable housing and workforce housing, and integrate them into the improving neighborhoods. 

 

Downtown Charlotte is mostly attracting the familiar gentrification cohort: singles, couples, older people whose children have left home. The bulk of the married-with-children middle-class has not only been living in the suburbs, it has been moving to the suburbs. Joel Kotkin, perhaps the most prominent of the downtown debunkers, declares flatly that, until families begin turning up in significant numbers on downtown streets, we are talking about a blip rather than a major cultural phenomenon.

 

Well, yes, but more bedrooms means more babies.  Young people will get busy, you know.

 

 

More babies soon means more toddlers, and preschoolers, and schoolchildren.  Postulate: the charter school movement has emerged as the marketplace’s workaround of the teacher’s unions and ossified municipal bureaucracies to create quality schools.

 

Beating a union the American way: by out-competing it

 

To me, that’s the point.

 

In the 1990s, a flurry of academics and journalists (me among them) wrote books lamenting the decline of community and predicting that it would reappear in some fashion in the new century. I think that is beginning to happen now in the downtowns of America, and I believe, for all its imperfections and inequalities, that the demographic inversion ultimately will do more good than harm. We will never return–nor would most of us want to return–to the close-knit but frequently constricting form of community life that prevailed 50 years ago.

 

Cities have revived because, in a world of information technology, close proximity is efficient – which makes it valuable.  As the cities have revived, they have attracted richer, smarter people, displacing the poorer and less well educated to the periphery. 

 

Arriving in a decrepit or inefficient city, the affluent immigrants have set about transforming it.  Home ownership changes behavior for the better, and makes residents into demanding customers.  They demand clean air and clean water – and they can pay for it.  As they do, the cities clean up.  They demand better schools – and get them either through reforming the public system or through a workaround like charter schools.  Housing makes people into investors in their communities.  They use their money to make change directly, and the political equity of their votes to make it indirectly.  In so doing, they clean up their environment – ecologically, sociologically, and politically.

 

Making another investment of political equity

 

Richer city, better municipal government.  Better municipal government, eventually better national government. 

 

Richer world, more democracy. 

 

And around the world?