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The Terry Thomas Building by Weber Thompson. Photo by Lara Swimmer. View an alphabet buildings slideshow on Flickr.

The Terry Thomas Building by Weber Thompson. Photo by Lara Swimmer. View an alphabet buildings slideshow on Flickr.


The Rise and Fall of the Air Conditioner

Joshua McNichols

Buildings consume about 40% of the country's energy. Much of that energy goes straight to the air conditioner. To cut down on that consumption, some architects are experimenting with old building techniques, from long before the age of air conditioners. But rethinking air conditioning means rethinking comfort.


Picture the ideal modern office building. The floors are so large, you could play a softball game and not worry about breaking a window. Fluorescent lights illuminate the floor evenly, dependably, even near the elevator doors, where the sun never shines. And the temperature never strays from a comfortable, 68 degrees.

But it wasn't always like this. To explain, architectural historian Kathryn Rogers Merlino takes me to a little patch of grass just north of Pioneer Square. She points to a shining white building above the trees, Smith Tower, Seattle's oldest skyscraper. A wealthy industrialist built it in 1914. That was a different time. A time before fluorescent lights and air conditioning.

Merlino: "Well, before the 1930s when mechanical air conditioning and ventilation was really the norm, a lot of these buildings had to rely on passive cooling systems."

Passive cooling systems don't use mechanical ducts or motorized fans to distribute conditioned air through a building. Passive cooling systems are much more primitive.

McNichols: So when you get hot, what do you do?

Merlino: Well, believe it or not, you'd actually open a window and let the air in.

To ensure that no desk was ever more than 25 feet from a window, the architects of that era had to be clever. They carved out big chunks of building, creating courtyards and lightwells. If you were a giant, looking down on these buildings from above, they'd resemble letters of the alphabet. You could call them alphabet buildings.

Merlino: "And so the shape would either be an 'O,' it could be an 'H' in plan."

"U" shaped buildings were also popular. The Smith Tower's footprint looks kind of like a letter "K." But opening a window can only take you so far. Inside Smith Tower, workers would sweat over their desks in summer. In the winter, they'd wear sweaters.

Then, everything changed. In the 1930s, building engineers invented mechanical air conditioning systems. These became very popular with office buildings. Unlike homes, offices need cooling most of the year, what with all the bodies and equipment inside. By the end of World War II, everybody with a big office building wanted an air conditioning system. After a while, nobody opened windows anymore.

Merlino: And I think our threshold and our comfort levels changed a little bit, culturally. We expected systems to be much more controlled. And so that idea that on a warmer day the interior of a building might be a little bit warmer was less acceptable, and it was more typical to control it from a central system.

Seattle used to have a nice collection of old alphabet shaped office buildings. Many were demolished in the 1970s. Those that remain have installed mechanical air conditioning systems. Their lightwells and courtyards are slowly being filled in with structural steel and rentable office space.

All this progress made some sense when energy was cheap. That's the way the architecture firm Weber Thompson designed office buildings for three decades. But when it came time for Weber Thompson to design and build its own office a few years ago, the young designers in the office wanted change. They wanted sustainability. They wanted operable windows and natural sunlight.

For inspiration, the firm looked to the age before air conditioning. Back to the alphabet. It built an "O" shaped building; a courtyard building.

Scott Thompson is one of the firm's founders. He stands next to a big window, overlooking the central courtyard.

Thompson: "I mean, these are old–school strategies, common–sense strategies that architects should really be looking at going forward as we design these buildings, and as energy costs continue to rise."

Thompson says this is Seattle's first big office building built without air conditioning since the 1950s. He thinks people are ready for a change.

Thompson: "We were in a hermetically sealed building for 18 years, and it was a constant battle; you were always too warm, or too cold. In this building, you have the opportunity to participate in your thermal comfort. In other buildings, you're really a slave to the thermostat."

When somebody gets too hot in Weber Thompson's building, they open a window on the building exterior. If they want a breeze, they open another window on the courtyard. Because heat rises, the courtyard acts like a chimney. It sucks up all the hot air in the building and spits it into the sky.

Thompson says this building is a laboratory, and his employees are experimenting with what it means to be comfortable. For example, when it's 90 degrees outside, it's probably 85 degrees inside.

Thompson says the office does reach those kinds of temperatures a couple days every year. On those days, employees come in early and leave early to avoid the heat. People learn to adapt.

McNichols: "So, do people wear shorts in the summer?"

Thompson: "We do. And short sleeved shirts, obviously; and on occasion, flip–flops."

Thompson says just three years ago, many developers didn't want to hear about sustainability. Now, it's completely turned around. When Thompson shows clients around his new office, they ask lots of questions. They're ready to give sustainability a try. Thompson says people are just more educated nowadays. Or maybe people just want an excuse to wear flip–flops.

For KUOW, I'm Joshua McNichols.

© Copyright 2009, KUOW

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