8 May 2013 – From Greentech:  Apple might be one of the world’s most secretive companies but it’s reasonably happy to share some of its learnings on energy efficiency.

Such as lower energy consumption in recent times, despite the number of employees at Apple headquarters going up. And that the energy efficiency case study at Apple’s Infinite Loop did not involve sleek aluminum housings with a minimum number of buttons, but rather replacing chillers and consolidating chiller loops.

“And it usually does come down to motors, pumps, chillers, dampers, rogue zones, and continuous commissioning. Nothing secret, and only sexy if you are an energy efficiency geek (like us),” says this article in Greentech.

Commenting at a recent sustainability event in the US, were Arik Cohen, principal at kW Engineering, who is also involved in Apple’s efficiency efforts and Mike Petouhoff, Global Energy Manager at Apple.

“When addressing the company’s chillers at Infinite Loop, kW Engineering detected that the original vendor had overstated savings by 300 percent with an assumed — and incorrect — load profile,” the Greentech article says.

“Taking matters into their own hands, the Apple Energy Team devised a new configuration and control strategy for the building’s chillers and cooling systems. The number of chillers was reduced from twelve to six, and the chiller paths were consolidated so that one loop served three buildings.

“The total cost savings for the chiller project was $300,000 per year and resulted in a 10-year payback on a chiller with a 23-year lifetime. The project also involved installing VFDs (variable frequency drives) on ‘both evaporator and condenser pumps and new control sequences enabled variable flow on both sides of the chiller.’”

Cohen noted that “Apple also implemented a number of control projects including advanced sequences to reset supply air and duct static pressure at the air handlers. Together, capital and control projects implemented over the past four years have yielded a 30 percent reduction in energy consumption, while head count has gone up.”

Petouhoff stressed that a “tenant improvement tracker” is of crucial importance if participating in a utility program.

The energy group at Apple wants the “strongest result at least cost,” said Petouhoff. “The most important thing is to work with utilities to get a structured tool for funding and implementation.”

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