Boring Topic Except Not

new_york_times:http://www.nytimes.com/2008/06/29/jobs/29career.html

By PHYLLIS KORKKI
Published: June 29, 2008
Q. Now that the air-conditioning is running in your office, you and some co-workers think it’s too cold. But others say they feel just fine. What’s going on?
Chris Reed

A. The problem is that the way people experience temperature depends on a range of factors, including body type, clothing, activity level and proximity to other people and to vents, computers and windows — as well as individual preferences and expectations.
At the same time, most modern office buildings have a one-size-fits-all design that can’t possibly accommodate all these variables. “You’re almost set up to fail when you put a lot of people in a building and give them one temperature,” said Gail S. Brager, a building science professor in the architecture department at the University of California, Berkeley.
Think of how much more control you have over your comfort at home, she said. You can open windows, turn on fans, heaters or air-conditioners, change clothes or move to a different room. At most offices, you lose that control. “Somebody else is pushing the button,” said Professor Brager, who is also associate director of the Center for the Built Environment at Berkeley.
Rather than creating optimal working conditions for everyone, she added, the goal in many offices “is to minimize the number of people who might complain.”
Q. It seems as if women complain about feeling cold more than men do. Is there a gender disparity when it comes to temperature’s effects?
A. Women do tend to feel colder in air-conditioned offices — for reasons of physiology and fashion, said Alan Hedge, an ergonomics professor at Cornell University.
The muscles of the body generate about a third of its heat, he explained, and women tend to have less muscle mass than men. In addition, women are often freer to wear clothing that leaves their arms, legs and the neck area exposed. (The ankles, he said, are particularly vulnerable to cold.)
Traditionally, women in offices have held more sedentary positions than men, he added, and the less you move around, the less heat you generate.
Q. Can temperature affect productivity?
A. Employees who are cold tend to work less efficiently, according to research by Professor Hedge. He measured computer keystrokes performed by office workers, at their actual workstations, in temperatures ranging from 68 to 85 degrees Fahrenheit. “At 85, they’re typing twice as much in a minute as they are at 68,” he said. The colder workers also made a greater percentage of mistakes, he said.
Temperatures in most buildings are usually set between 70 and 74 degrees, depending on the time of year, he said. But his studies have shown that a temperature between 72 and 79 is optimal for worker productivity and comfort, assuming a reasonably flexible dress code. (Above 79, some workers may start to wilt.)
Q. Why, then, are offices kept so cold in the summer, when keeping them warmer would save energy, too?
A. For one thing, the workers who are required to wear suits and socks or nylons would probably be miserable — especially the active, well-muscled ones. And even with a relaxed dress code, there is a limit to how much you can take off, whereas you can always add layers of clothing.
In addition, most buildings are “overdesigned,” with the makers of the ventilation system assuming 100 percent occupancy, Professor Hedge said. Occupancy affects temperature, because heat is generated by the people around you, he explained. In reality, a building is almost never fully occupied.
Q. Do other factors in the air beside temperature affect comfort level?
A. Experiencing a variety of temperatures and air velocities is stimulating, said Professor Brager. This can be hard to achieve in most modern office buildings, which are essentially sealed envelopes cut off from the outside, she said.
She is a proponent of having office windows that open and maintaining other features that keep workers more connected to the outside.
Studies have shown that a condition called “thermal boredom” can lead to fatigue and reduce productivity, she said, noting the refreshing effect of a gentle spring breeze.
She has conducted field studies on workers around the world, and when people who are indoors have a closer tie to the outdoors, they accept — and in fact prefer — a greater range of temperatures, she has found.
High humidity is also an air comfort factor: It is much more draining than heat, and air-conditioning systems can be set higher and yet dryer to accommodate that, Professor Hedge said.
Q. Are modern building designers trying to incorporate some of the new findings on office temperatures?
A. Yes, with the added incentive of achieving considerable energy savings. Building designers, long behind the times, are starting to catch up with features like temperature and ventilation systems for individual workstations, Professor Brager said.
Although these features may be expensive upfront, they can pay off in the long run, she said: “If we give people control over the environment, we can let the temperature in buildings float over a wider range, which can simultaneously save energy and give people greater comfort.”