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Smart buildings get smarter

Robert L. Mitchell | Oct. 23, 2012
Behind the glittering, sculpted glass skin of the San Francisco Public Utilities Commission's new 13-story headquarters beats the heart of one of the most energy-efficient office buildings in the world.

The system also has allowed Microsoft to start moving toward a just-in-time maintenance and tuning schedule, a trend known as continuous commissioning. Following a traditional maintenance schedule, more than 26,000 filters would be changed quarterly, and each of the more than 800 building air-handling systems would be tuned in a five-year rotation. With the new system, Smith says, "we were able to go much deeper with the data and tune all [30,000] of the assets, not just the large building systems." The problem with tuning 20% of the systems each year is that, as with cars, the efficiency and performance of building systems degrade gradually over time. Now Microsoft uses analytics to replace each filter based on actual usage.

"Instead of changing them on a schedule, we change them at the right time. That's the intelligence we're talking about -- a building generating its own work orders," Smith says. And by prioritizing maintenance needs, the facilities organization can continually tune the campus. "It compresses the five-year cycle into one year for a total savings of $1 million," he adds.

The Redmond campus project, which is about 20% complete, has also allowed Microsoft to reduce its peak energy demand. "We were causing our own peak demand just by how things were occurring in the building," Smith says. Resequencing when different building systems came online smoothed out the demand curve. In the pilot phase, Microsoft has so far shaved energy costs by 6% to 10%, while the application of analytics for fault detection and diagnostics is projected to save more than $1 million annually. "Our payback on this will be about 18 months," he says. That payback period is shorter than it would be in other states, however, because Washington has the country's third lowest electric power rates.

Saving Energy

Condition the People, not the Building

The best-laid plans for constructing smart buildings often fall victim to poor processes, contends Tom Hartman, principal at The Hartman Co., an engineering design firm. Take, for example, how buildings are heated and cooled. Most systems focus on conditioning the building envelope, or areas that include a half-dozen or more office areas. What's more, many systems are still designed to wash air around the exterior walls because that's where most heat loss used to occur.

"We need to change the philosophy from conditioning the building to conditioning the people wherever they are," says Hartman. Low-cost sensors and wireless networks can help make that possible. But the number of sensors -- measuring occupancy, CO2, temperature, humidity, light and more -- would need to be vastly increased, to an average of up to 12 per occupant, he says.

While the ability to create integrated, all-in-one sensors will help keep costs down, the increase in the number of data points that need monitoring would increase from an average of 3,000 to 4,000 in a large building today to more than 20,000 for a building with 1,000 occupants.


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