How Fault Detection And Diagnostics Reduces Energy Costs
April 8, 2014 - Contact FacilitiesNet Editorial Staff »
Today's briefing comes from Rita Tatum, contributing editor for Building Operating Management. Microsoft has seen significant energy savings from deploying fault detection and diagnostics across its campus. In 2012, more than 4 million square feet of space on the Redmond campus have the smart solution in place, and Darrell Smith, director of energy and facilities, expects to save $1.5 million in energy costs for fiscal 2013. That savings is coming from "casting a net" of fault rules across the buildings to identify assets that are wasting energy because they are not working as designed or have incorrect set points. The payback is less than 18 months, which is particularly noteworthy since the state of Washington has rock-bottom power prices. "We have the third lowest utility rate in the country," Smith points out.
It's not that the buildings were designed inefficiently. A number of the worst performing were built to LEED Gold and LEED Silver standards. But under the old system, each building was retro-commissioned once every five years to make sure it was operating as designed. It was simply impossible with so many buildings to get to each one any faster.
That lag led to problems. For example, a sewer pump developed issues so the exhaust fan was taken off the carbon dioxide sensors and run at 100 percent. The override remained that way for a year before it was found and reversed.
Facilities personnel used to go and look to see what was broken. "Now, I know the actuator's broken before you tell me and I know how much it will cost if I don't make that repair," observes Smith.
But the intelligent building management system does more than indicate a $50 variable air volume fault versus a $20,000 air economizer problem.
"It also lets me drill down to the floor so I can evaluate the asset value and determine the priority," explains Smith. "It may be a $300 fault, but the impact on our business [could be] such that it's actually more important to fix the $300 fault before another fault that could represent $15,000 in wasted energy."
In addition to fault detection and diagnostics, Microsoft's system also manages alarms and assists in energy management functions. Smith estimates 2 million data points are currently connected across the campus. When all Microsoft buildings are on the new system, it may be handling 500 million data transactions every 24 hours.