Air Conditioning

It has been an unusually hot summer in the U.S. this year, breaking temperature records from Chicago to Denver. The heat exacerbated already terrible firestorms in Colorado, and led to a so-called "super derecho" line of storms that swept from the Midwest through to the Atlantic in the first week of July. A derecho is a powerful windstorm, accompanied by lightning and rain, fueled by hot air and ripples in the jet stream. Derechos can often give rise to tornadoes. Fortunately, this year, few funnel clouds were reported but 90 mph winds knocked down trees and power lines, leaving an estimated 2.7 million folks without power.


Without power, people can't run their air conditioning. Without air conditioning, the elderly, people with respiratory ailments, and those suffering from heart disease are at risk of dying from hyperthermia.  


The air conditioning-heat wave phenomena is a bit like a snake eating its tail, however. 5% of the nation's electricity is used to run A/C, producing 100 million tons of carbon dioxide per year, leading to, well, global warming. Despite conservative counterattacks, it has become accepted science that a warming planet leads to longer, more severe weather events across the globe.

Aww, little Will is growing up. His first air conditioner!

This week one year ago, the lady and I moved to Chicago from Alabama in the middle of an epic heat wave in the city. Our little studio, with two huge southern windows and no blinds (yet), didn't stand a chance. We suffered through the rest of the summer, sticking to our pillows and vinyl-cushioned desk chairs. I was unemployed at the time, and, after a morning of feverish resume-sending and portfolio-improving, I would walk down to the lake and dunk myself in glacial Lake Michigan. This would buy me a half-hour of relief, until the sun dried me off and I had to sweat it back to the apartment.


However, this summer, with a few more dollars in our pockets, we decided to invest in a window air conditioner. Memorial Day weekend, we pulled the trigger on a small unit. We've been living in cool, dry bliss ever since.


I've lived in a succession of hot, humid climates: Baltimore, Virginia, Alabama. Growing up, we got central air sometime in my childhood, when I was 6 or 7. In Virginia, neither my dorm, or later, my apartment, had a/c, but I also didn't live there in June and July. In Alabama, both my apartments had ceiling fans and wall units that struggled to keep up with the crushing heat.

Schematic of absorptive chiller, courtesy of Treehugger.

Absorption air conditioning, based on the expansive properties of ammonia gas, was first pioneered by Michael Faraday in 1820. Various inventors tinkered with both absorptive and compressor-based technologies in the years following, but mainly in the pursuit of making ice. In 1902, Willis Carrier invented the first modern air conditioner. It was designed to control heat and humidity in a printing plant, as the excessive moisture in the air was preventing the ink from adhering and drying. Like any new technology, it was expensive at first, but gradually spread. Some of the earliest adopters were movie theaters, which used the systems to great effect. From there, A/C spread, well, everywhere. We now have it in our houses, cars, and even our stadiums.


Air conditioning made vast swaths of the planet more livable. At the same time, we are rapidly losing both our tolerance for heat and the cultural memories of heat-adaptive ways of living. We design our houses differently, ignoring siting, solar orientation, window placement, plantings, and predominant breezes. We don't sit on porches, sleep in parks, and have a low cultural tolerance for normal human sweat.


But here I sit, window unit humming. The instant comfort is addictive. I feel a little guilty every time I switch on the unit. I remember back to childhood, with my mother hollering at me every time I opened the door: don't let the a/c out! Air conditioning represents more and more of our energy use, especially in warm climates. The coal-burning power plants providing that electricity are only fueling the cycle, warming the planet and powering the extreme weather events that further destabilize the climate.


There are alternatives! Air conditioning has only existed for .0022% of human history. We managed pretty well for a long damn time. Evaporative systems work well in low-humidity climates. Absorption chillers can use solar or waste heat, which is promising. And then, of course, there are all the passive strategies like siting, shading, and fans. These served me well in Arizona, where I lived without a/c for a year.


I don't feel like much of a guerilla writing this. I have an ice-cold drink, a cool room, and a mechanical breeze. Life is good. 


It hit 102 degrees today on my commute home from work. Nobody wants to live in that. And that is the biggest obstacle.