It has taken me many years to finally admit that air conditioning is an essential part of our lives and our society. It’s like driving; we made it essential by designing our cities around the car. We made air conditioning essential by designing our houses and offices around it, and once we had those cars and air conditioners, moving to south and southwest where you can’t live without either. We are culturally attuned to it, and we're not going to start sleeping in the afternoon to avoid the heat and having dinner at ten at night. (Although one can make the case that the people in Barcelona who do are having a lot more fun than we are.)
However that doesn’t mean we have to just willfully waste the cool air and the energy it takes to make it. Kate Murphy wrote a long article in the New York Times Magazine, Enduring Summer’s Deep Freeze, where she catalogued the different ways stores turn down the thermostat to be cooler than their competition. Or why office managers keep it cool to keep men in the required suits and ties comfy and to perhaps dampen the tendency of women to wear more revealing lighter clothing. “Sixty-eight degrees feels a lot different if you are wearing a wool turtleneck, slacks and boots versus a poplin sundress and sandals.”
Everybody is yelling at everyone in that article. Engineers blame architects for not wanting to look at sensors, architects blame engineers for designing systems with too much capacity, everyone blames developers for cheaping out on good controls, and even the green building standards that call for more efficient and well-insulated buildings get some of it:
Better sealing and insulation keeps air-conditioning from escaping but it also keeps fresh air from entering. So cool air is often kept blasting to meet mandated air quality standards for levels of carbon dioxide that build up in the absence of outside air. The cool air also controls humidity, which can lead to every building manager’s nightmare: mold.
In France, a doctor studied the health of 770 office workers and found that those working in air conditioned offices (a lot of people there don’t) were “almost two-and-a-half times more likely to suffer from respiratory infections than those in naturally ventilated buildings.”
In the study, the French doctor examined the levels of air temperature, humidity, airborne bacteria and fungi in both air-conditioned and naturally-ventilated buildings. He found that seven out of eight symptoms were associated with exposure to air conditioning at work.
In Berkeley, a study at Department of Energy’s Lawrence Berkeley National Laboratory found significant health problems arising from too much air conditioning.
In summer, a variety of building-related symptoms such as headache, fatigue, and difficulty concentrating were increased by over 50 percent in the buildings kept below 73.4°F (23°C). These buildings, kept too cold for comfort in summer, included almost half the buildings measured in summer. These symptoms thus might be expected to decrease if buildings were air-conditioned less and kept warmer in the summer.
I used to be far more doctrinaire about this issue, and took the position that the environmentally correct thing to do was to live without air conditioning. That if it is too hot in Atlanta, then one should move to Buffalo. In 2005, I wrote:
We should consider also the insidious effect of central air — how it enables the development of parts of the country previously uninhabitable and which would still be but for the constant cooling, and how it is destroying the street culture of areas already established. How we are sacrificing neighbourhood and community by forcing our immediate personal climate to adapt to us instead of us adapting to it.
Ten years later, my position is a bit more nuanced. I wrote in MNN earlier about how AC was pretty much a necessity now:
I don’t think that’s realistic anymore, given that so many people live in the South and Southwest now, places where it is almost impossible to live without air conditioning. Our summers have become hotter, and we have become used to being in a cocoon of cool air as we move from house to car to office.
But also as I noted in that article, it’s all about design. There's no reason that an office building cannot be designed to allow more individual controls and zones so that employees can adjust the temperature themselves. There is also nothing wrong with using clothing to adjust for a little variance in temperature. As engineer Robert Bean notes, “thermal comfort is a condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation.” It’s how you feel, not what the thermostat says, that matters. So if you spend a lot of time outside and don’t over-air condition your house and are acclimatized to warmer temperatures than your office neighbor, you're going to feel colder than she does and a light sweater is perhaps the best way to adjust. The managers are setting it to the lowest temperature because you can easily put on a jacket to get warmer but you can only take so much off to get cooler and maintain decorum. It's hard to fix that.
Air conditioning is not going away, and as people all over the world get wealthier, they're all going to want more of it. About the only things we can do over the longer term:
- design our houses and buildings to need less of it, (with more insulation and better solar control and better architecture and HVAC design)
- adapt our bodies to be comfortable with a little less of it (by turning up the thermostat a bit and adapting)
- and stop creating the conditions that make us need more of it (by getting off fossil fuels and electrifying everything.)
Beyond that, you can always move to Buffalo.
Related on MNN and TreeHugger:
- There's more to comfort than just picking a furnace or an air conditioner
- Can air conditioning make you sick?
- The Deluded World of Air Conditioning Revisited