A room temperature of one's own
Better living through 'personal climates'
(istockphoto)
At work, if there’s anything people love to complain about more than the weather outside, it’s the weather inside. A friend of mine recently revealed that she sometimes sports a hat, scarf, and coat at her desk, partly to make a point. Another bemoans that in his office, he sweats all winter. Indeed, according to several surveys, the number one complaint about office environments is that it’s too cold. Number two: It’s too hot. Often, both complaints come from the same building, possibly even from neighbors in adjacent cubicles.
After all, trying to satisfy everyone with a uniform climate is an impossible task; people simply have different thermal preferences. The industry guidelines, resigned to this reality, stipulate that at least 80 percent of building occupants should find the temperature acceptable - a rather modest aim, it would seem, by the standards of most industries.
Temperature is only one of the issues. Since everyone is breathing the same air, infections spread easily. Indoor air can also cause so-called Sick Building Syndrome - itchy skin, dry eyes, headaches. And ailing, uncomfortable employees are unlikely to be working up to their full potential. Problems with indoor environmental quality are estimated to cost the US economy billions of dollars per year in lowered productivity. Despite these flaws, climate control in office buildings consumes an enormous amount of energy, constituting one of the country’s major sources of greenhouse gases.
But according to growing number of architects and engineers, there’s an ingenious way to address all of these problems at once: provide all a building’s occupants with jurisdiction over their own “microclimates.” The basic idea is to stream air directly to individual workstations - usually through nozzles on the desks or plenums under the floors - and allow occupants to control the temperature and airflow where they sit. Such systems can enhance comfort, health, and productivity. Recent studies also indicate their potential to save energy, because the building’s base temperature can be kept closer to the outside weather, and each unit runs only when the desk is occupied.
“You can bring 100 percent of the people to comfort,” says Edward Arens, a professor of architecture at University of California Berkeley and director of the university’s Center for the Built Environment. “The other side is the energy savings are really huge.”
In the past few years, academics have designed several new models, which are being implemented and tested in real buildings. Researchers at the Center for the Built Environment have developed a prototype, and plans are underway to install the devices at office buildings in San Jose and Alameda, Calif., as well as in the Orinda City Hall. Exhausto, a Danish company, has collaborated with a Danish university to launch a personalized ventilation system, which has been installed in two banks in Denmark. And Syracuse University’s new Center of Excellence Headquarters, a building that will be dedicated in March, has workstations with personal environmental control, where researchers will monitor the human response and the energy impact.
A system has been commercially available since the late 1980s, but the units have always been expensive - up to $2,000 each - and some experts say it’s difficult to retrofit existing buildings to accommodate them. There is, however, evidence that they are worth the initial costs. In the early 1990s, a study concluded that such a system paid for itself in under two years, thanks to higher productivity. Still, productivity gains are hard to guarantee. Sticker shock, along with the slow pace of change in the building industry, has severely limited adoption so far.
But now, the findings about energy savings will appeal to the growing number of firms aspiring to be green - and the promise of lower electric bills could help justify the costs of installation. What’s more, at least one cutting-edge variation is far less expensive than earlier models.
Often, being eco-friendly means sacrificing luxury, and tailoring to individual preferences means consuming more resources. The appeal of personalized ventilation is that it inverts these equations: Enhancing comfort by customization, advocates say, can actually reduce energy use. As research and experimentation continue, the idea may finally start to gain a foothold.
In a culture that relentlessly caters to individual needs, it’s a little surprising that personal environmental control isn’t already common in workplaces. And the idea has been around for some time. In the late 1980s,
Research has shown positive effects of this system on comfort and productivity. A 1992 study conducted by Walter Kroner of Rensselaer Polytechnic Institute examined several hundred workstations with Johnson Controls’ modules at the West Bend Mutual Insurance office in Wisconsin. The study found that complaints about temperature disappeared almost entirely. It also credited the modules with a 2.8 percent gain in productivity, and concluded that the system paid for itself in 18 months, through increased productivity alone. (Energy use was not tracked.)
A 1998 study of a
“We have an industry that’s all based on the concept of centralized ventilation,” says H. Ezzat Khalifa, a professor of engineering at Syracuse University. “Even though [personal environmental control] is without dispute a very good thing in terms of improving people’s productivity, people have to weigh the advantages, which are overwhelming, against the costs, which are still high.”
New research has focused on the potential for energy savings. In a recent paper, Stefano Schiavon, a postdoctoral scholar at Berkeley’s Center for the Built Environment, simulated a hot and humid climate. He found that without appropriate strategies, a personalized ventilation system could actually lead to a surge in energy consumption. But with energy-conscious measures, such as allowing the overall air temperature to rise, the system could reduce energy use in a typical building as much as 51 percent.
Schiavon’s colleagues at the center have developed a substantially cheaper alternative. Professor Arens and his team have designed low-tech devices that can be installed at any workstation, without needing to connect to the central ventilation system. The prototype uses fans in hot weather, and heat lamps in cold weather, both extremely low-wattage. (It does not supply fresh air, so it would not reduce the spread of infections.)
Intriguingly, their studies suggest that we can target certain body parts in order to efficiently achieve contentment. In hot weather, cooling the head and hands apparently suffices to make us comfortable. At lower temperatures, as long our hands and feet are warm, we feel fine (within a reasonable range, of course). In a recent experiment, subjects worked at desks in various simulated climates. In the fake Minneapolis winter, each subject had access to a palm warmer, foot warmer, and heated computer mouse. In the pretend Fresno summer, fans cooled the head and hands.
“When you make people comfortable, you just need to target those locations,” says Hui Zhang, the paper’s lead author.
They allowed the overall “ambient” temperature to drop to 64 degrees Fahrenheit in cold weather, and to rise all the way to 86 degrees in the hot climate. Even at those extremes, subjects were comfortable at their workstations. (Bathrooms and hallways could have their own climate control - or people could endure suboptimal temperatures before returning to the relief of their own desks.) Energy savings ranged from 27 to 44 percent. Arens estimates that if and when these devices are marketed commercially, each unit could cost less than $100.
The notion of personal environmental control sounds fancy, but the basic principle, after all, dates back to the use of the feather fan. Over the last few decades, we have grown accustomed to energy-intensive office climate systems that create a uniform, highly artificial indoor environment. In some of these new systems, the office at large would not be so starkly distinguished from the outdoor weather - you would actually encounter some heat in August, for example. Whether people will accept that remains to be seen. But it’s hard to imagine that it would generate more complaints than the status quo.
Rebecca Tuhus-Dubrow is a contributing writer for Ideas. She can be reached at rebecca.tuhusdubrow@gmail.com. 
