An Alternative Theory of Europe’s AC Problems

Europe’s heat wave has finally ended — and good riddance. The continent recorded at least 1,300 excess deaths over the past week, according to the World Health Organization. Mortuaries in Paris and other cities were overwhelmed.

North America will now get its turn with summertime heat: At the end of this week, New York, Philadelphia, and other cities down the East Coast — including several where World Cup knock-out games will be played — could see their hottest temperatures since 2012.

As I wrote last week, these bouts of extreme heat are caused by climate change. Severe and record-breaking heat waves are one of anthropogenic global warming’s clearest and most indisputable symptoms.

But as I also wrote last week, Europe and North America have very different ways of dealing with extreme heat. Most Americans have air conditioners, but they remain rare in Europe — and especially in northwestern Europe, including France, Germany, and the United Kingdom.

Since last week, I have read countless explanations about why Europeans don’t have air conditioning at the same rates as Americans — or even Canadians. Perhaps Americans and Europeans have a different relationship to suffering, goes one theory, or maybe the European left has managed to politicize air conditioning in a way that the American left has never tried to do. The cultural divide here is more real than I once would have thought: In Paris, the deputy mayor chided Americans for even asking about Europe’s AC use; she argued air conditioning “contributes and aggravates” to air pollution and climate change. In Florida, meanwhile, we name elementary schools after the inventor of mechanical refrigeration.

Throughout all of this, I’ve assumed that Europeans would purchase air conditioning as the warming climate demands it. Much like the Pacific Northwest, where AC adoption lagged the rest of the United States for decades, much of Western Europe used to enjoy a climate where AC was unnecessary. That changed in Oregon, Washington, and British Columbia after the 2021 heat dome. Now that summertime highs are rising in Europe, too, it seemed obvious that people would go out and buy window unit air conditioners — and where they can’t buy them because of local laws, they’ll push for reform.

It had not occurred to me, though, that a simpler obstacle might be blocking Europe’s adoption of AC. Jonas Nahm, a professor of industrial strategy at the Johns Hopkins School of Advanced International Studies, wrote in with a question: What if it’s the windows?

Do you know about Europe’s superior windows? Unlike the United States, where most of our windows hang on a sash and open vertically, the dominant form of window in Germany, Austria, France, Italy, and the rest of the Blue Banana are tilt-turn windows. This distinctive form of fenestration has a dual-action hinge, meaning it can tilt, opening at the top to let in light or air; and turn, swinging fully open on its hinges.

Tilt-turn windows are superior in most respects to our American sash windows or casements. Because they close more securely, they provide better protection against the elements; because you can swing them into a room and access both sides of a pane, they are easier to clean; and because you can tilt them from the bottom and crack them open at the top, they can ventilate a room without creating a draft. They are also ubiquitous in western Europe. Asked once what Germany meant to her, Germany’s former Chancellor Angela Merkel replied: “I think of well-sealed windows. No other country can make such well-sealed and nice windows.”

They are superior in all respects, I would say — except for one. When Americans in older buildings want to get an air conditioner, we go and buy a window unit, then we slide up the sash window and install it. But tilt-turn windows are not so accommodating. Those who have them must instead go and buy a portable AC unit that sits entirely inside a room, snake its hose out the top of the window, and then either purchase a fabric barrier or jerry-rig towels to seal off the crevices.

If you can’t buy a window unit, in other words, then your air conditioning options narrow. You either have to install an unsightly portable AC unit. Or you have to retrofit your entire home and install mini-splits — a far more expensive renovation that may not even be possible in historic or rental buildings.

Can windows alone explain Europe’s differing approach to air conditioning? It certainly explains a gap I’ve noticed in the discourse, where some Europeans seem to see air conditioning as an exorbitant luxury and Americans see it as, well, just another $250 purchase. It matters, too, that most Europeans heat their homes with radiators, meaning there is no forced-air ductwork system that a central air system can piggyback on. (Of course, my 100-year-old apartment building has radiators, too — but we have sash windows, and therefore window units.)

As it happens, I’ve lived in a home in the United States that had tilt-turn windows. An old German landlord of mine installed them in about half the house. We had window units too, but we stuck them in the few rooms that still had sash windows.

But of course, maybe what you don't have always seems more exotic to you. Not so long ago, I found myself in a smoky Berlin bar talking with a German about how much I liked and respected their windows. My companion was confused and asked me what windows were like in America, and I pantomimed opening a sash window and sticking my head out the bottom.

He was thrilled. Wait, he replied, just like in the movies?

I promise tomorrow's newsletter will not be about windows or air conditioning.