Question: How many air conditioners were sold in 1947? Answer: 47,000.

By 1953, that number had mushroomed to 1,045,000. In 1970, 6 million units were sold.

This leap is astounding even by iPhone standards. Of course, with each unit installed in a poorly insulated house, the amount of energy that Americans used per capita rose.

In Adam Rome’s The Bulldozer in the Countryside, he links that rise with the end of regional building traditions that took into account the differences between the climate in Georgia and Idaho. Air conditioning “freed architecture from the constraints of climate.” But really, it wasn’t architects who benefited the most. The nation’s builders needed to sell houses and they found air conditioning a potent new feature of the home machine. They promoted cheaply built tract homes with air conditioners, spouting a self-fulfilling prophecy that it would be their next big thing.

Take the advertisement above. “Day and Night Air Conditioning throughout the house helps guard your family’s health…. actually washes, filters, and purifies the air you breathe.” Yum, taste that scrubbed air! Air conditioning makes you healthy! Live Better Electrically!

Traditional technologies like breezeways and basements and porches and screens for windows were done away with. Why bother with simple techniques like opening the window or orienting a house when you could use a few more dollars of natural gas or coal to cool the place down? In a world of unlimited energy, it makes sense, sort of.

“Of course, the use of air conditioning allowed homeowners to enjoy a new degree of comfort, but a goodly portion of the residential air-conditioning load simply replaced the comfort once provided — at little environmental cost — by good design,” Rome writes.

By 1956, New York Edison saw its summer load outstrip its winter load. How to balance the load? Increase demand for incredibly inefficient electric space heating by pricing it below natural gas, even though it was more costly. Get people locked into space heating and you’d have them for the duration of that house’s life. And with the government widely promoting the idea that atomic power was going to make electricity cheaper in the near future, it made sense to get people locked in early. Make the blades cheap, basically, so people build the razors.

“By the early 1960s, accordingly, almost 100 of the nation’s utilities offered special rates for electric heating… for monthly use above three or four hundred kilowatt hours — a level only homes with electric heat would reach — the rates were rock-bottom,” Rome continues.

The Live Better Electrically promotional campaign promised electricity as the answer to a better life. For all you really need to know about the campaign, watch this old commercial, which features a special cameo by Ronald Reagan.

The point of all this history is that when we see something from the past like air conditioning or electric space heating gain wide consumer acceptance, it’s easy to assume that the technology simply got better. People wanted it! Consumers, surveying the scene, simply picked the best available solution. We discount the lobbying and strategy of the firms as well as government’s involvement and ascribe all the adoption to “technological improvement.”

But take examples that we know well today, say, touchscreens for cell phones, and it’s hard to deny that Apple’s design, strategy, and marketing changed the technological path for mobile phone input devices. The pricing strategy, in particular, seems inspired. Other cell phone companies had tried to introduce the technology of the touchscreen and all had failed.

Now, you give an iPhone user a phone without a touchscreen and it feels broken, even though (I say this as an iPhone user) they absolutely suck relative to normal phones for texting and making phone calls, the dominant services that we associate with mobile phones. Was it the technology? The app store? The design? Sure, it was all of those things, which is why it’s so strange that when we look back in history all we see is what the technology allowed, and not what the people did.

In energy, this tendency gets formalized into the forecasts that companies, agencies, and analysts make about the future. Future energy demand is hammered into numbers and then decisions are made on the basis of that projected demand to build new plants or deride renewables or conservation.

But energy demand is a complex beast! Companies can promote or slow energy demand growth. Consumers can, too. And yet we act like projections made 30 years down the road are somehow predictive, even though just about everybody has been wrong in the past. Beware people who tell you they know exactly (or even roughly) how much energy people in the future will use. People with a vision of how much people should use to attain social goals? That’s a way of thinking I can get behind.

(There’s no real reason for energy demand to rise in the U.S., anyway. Measurable indicators of quality of life doesn’t really rise with more energy usage beyond beyond about 110 gigajoules per person per year, energy researcher Vaclav Smil has found. U.S. consumption is about 330 GJ/year.)

Image: flickr/TeamPerks from an awesome set of tract home brochures from Orange County.