Climate control for your desk
We are used to taking command of our personal climate in planes and cars by using simple controls. Why not in buildings too? A study of the effect of installing individual air-conditioning vents at office desks, and putting controls at each person's fingertips, suggests it can cut a building's energy use in half. The approach costs more to install than a conventional system, and has never taken off commercially. But engineer Stefano Schiavon at the University of California, Berkeley, and colleagues say their research shows the idea is worth revisiting, as companies and countries seek to cut emissions. They simulated an office building in a hot, humid climate like that of Singapore, where air conditioning is required all year round. Results showed the building's energy use was cut by 50%. Personalized ventilation means less air needs to be cooled and pumped through a building because air is blown only at desks, and not throughout entire rooms. "In an environment like Singapore, it's pretty clear that these systems would pay for themselves in energy savings," Schiavon says. Air conditioning accounts for the bulk of electricity used by buildings in Singapore. Past research has shown personal ventilation can also make people more comfortable, and suggested that it can limit the spread of airborne diseases. The personalized approach isn't always suitable, though. Only workplaces where people tend to stay in one place would benefit, points out environmental engineer Peter Nielsen of Aalborg University in Denmark. Savings are also smaller in cooler climates, where on cold days the number of people directing warm air onto themselves causes the room to overheat.