Summer’s Deep Freeze: New York Times reporter Kate Murphy discusses over-air-conditioned offices and apps like Comfy which let users control the temperature of their offices. Comfy got its start at CITRIS in Sutardja Dai Hall, where the UC Berkeley company prototyped and tested the smart technology.
by Kate Murphy | Reposted from The New York Times | 07/04/2015
It’s summertime. The season when you can write your name in the condensation on the windows at Starbucks, people pull on parkas to go to the movies and judges have been known to pause proceedings so bailiffs can escort jurors outside the courthouse to warm up.
On these, the hottest days of the year, office workers huddle under fleece blankets in their cubicles. Cold complaints trend on Twitter with posts like, “I could preserve dead bodies in the office it’s so cold in here.” And fashion and style bloggers offer advice for layered looks for coming in and out of the cold.
Why is America so over air-conditioned? It seems absurd, if not unconscionable, when you consider the money and energy wasted — not to mention the negative impact on the environment from the associated greenhouse-gas emissions. Architects, engineers, building owners and energy experts sigh with exasperation when asked for an explanation. They tick off a number of reasons — probably the most vexing is cultural.
“Being able to make people feel cold in the summer is a sign of power and prestige,” said Richard de Dear, director of the Indoor Environmental Quality Laboratory at University of Sydney, Australia, where excessive air-conditioning is as prevalent as it is in much of the United States. He said the problem is even worse in parts of the Middle East and Asia.
Commercial real estate brokers and building managers say sophisticated tenants specify so-called chilling capacity in their lease agreements so they are guaranteed cold cachet. In retailing, luxury stores like Bergdorf Goodman, Neiman Marcus and Saks Fifth Avenue are kept colder than more down-market Target, Walmart and Old Navy. Whole Foods is chillier than Kroger, which is chillier than Piggly Wiggly.
There’s also the widely held misconception that colder temperatures make workers more alert and productive when, in fact, research shows the opposite. Studies have shown people work less and make more mistakes when the air temperature is 68 to 72 degrees Fahrenheit versus 74 to 76 degrees. Moreover, some research indicates feeling cold can take a psychological toll, making people untrusting, uncommunicative and unfriendly.
As infants we learn to associate warmth with the safety of our parents’ arms. Our subconscious equates cold with vulnerability, which partly explains why people can be so miserable when they are chilled.
A region of the brain called the hypothalamus is responsible for our body’s thermoregulatory system, constricting blood vessels when we are cold and dilating them when we are hot to maintain a safe core body temperature. Your physical discomfort is essentially the hypothalamus prodding you to say, put on a sweater if it’s chilly or fan yourself when it’s hot.
Extreme temperature changes like entering a freezing lobby on a sweltering summer day may feel good at first, but it makes the hypothalamus go nuts, intensifying physical and psychological discomfort when the initial pleasure wears off — as if to say: “A blizzard is on its way! Do something!”
“It’s left over from a time when it was dangerous to have that kind of change in temperature,” said Nisha Charkoudian, a research physiologist with the United States Army Research Institute of Environmental Medicine in Natick, Mass.
The problem is compounded by building managers who, surveys indicate, typically don’t adjust the temperature set point higher in summertime when people wear lighter and more revealing clothes than they do in wintertime. Since thermoreceptors (nerve cells that sense temperature changes) are on your skin, the more of it you have exposed, the colder you are going to feel. Sixty-eight degrees feels a lot different if you are wearing a wool turtleneck, slacks and boots versus a poplin sundress and sandals.
However, you can understand managers’ bias toward keeping the lower, wintertime setting when many are men and might wear ties and jackets no matter the season. They may be even less inclined to bump up the thermostat if they are heavyset, as body fat is the ultimate heat insulator.
Air-conditioning systems are also usually designed for worst-case scenarios — full occupancy of a space on the hottest day of the year. As part of that calculation, designers might have assumed heat loads that factor in older-model computers and less energy-efficient lighting that radiate much more warmth than the machines and bulbs used today.
And, engineers say, they might add a 20 percent upward correction, just to be on the safe side. A result is systems with ridiculous overcapacity that don’t run well on low settings.
“It’s analogous to a high-tune car where you have to keep your foot on gas to keep it from stalling out,” said Edward Arens, professor of architecture and director of the Center for the Built Environment at the University of California, Berkeley.
Paradoxically, another reason for aggressive air-conditioning is energy-efficient building construction. 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.
STILL, Mr. Arens and his colleagues found that when they reduced airflow in several office buildings during the summer, including ones on the Yahoo campus in Sunnyvale, Calif., air quality was not diminished and it cut employee cold complaints in half as well as reduced the energy bill by as much as 30 percent.
While architects like Mr. Arens point the finger at engineers for designing air-conditioning systems with too much capacity, engineers can justifiably point the finger back at those architects who often have an aesthetic aversion to thermostats.
“Architects try to convince mechanical engineers to hide sensors so they don’t mess up their beautiful design, so you find them in quite out-of-the-way locations” like within air inlets on the ceiling, where, because heat rises, they provide less than accurate readings, said Jon Seller, general manager of Optegy, an energy management consulting firm based in Hong Kong, which specializes in maximizing the efficiency and automation of air-conditioning systems.
A couple of computer scientists have developed a smartphone app that proposes to solve that problem by making people the thermostats. Users can tell the app, called Comfy, whether they are hot, cold or just right. Over time, it learns trends and preferences and tells the air-conditioning system when and where to throttle up or throttle back the cooling. So far it’s used in a dozen buildings, including some of Google’s offices and some government-owned buildings, for a total of three million square feet. The developers claim Comfy-equipped buildings realize savings of up to 25 percent in cooling costs.
“We have a lot of data that people are most comfortable if they have some measure of control,” said Gwelen Paliaga, a building systems engineer in Arcata, Calif., and chairman of a committee that develops standards for human thermal comfort for the American Society of Heating, Refrigerating and Air Conditioning Engineers, or Ashrae.
Of course, for fresh air and comfort, engineers and architects tend to agree the most effective control is being able to open and close the windows. No app required.
Image: Olivier Schrauwen