The second floor of the NetApp data center manages the mix and flow of air through the building. Fresh outside air enters the floor from the rooftop air inlets. When the temperature is cool enough, the air handler units (pictured above) will move the air into the first floor data halls. The air handlers are each located directly above a data hall so the cool air can be dropped directly into the cold aisle. Pressure sensors provide data that allow the velocity of the air handlers to be adjusted in response to changes.
How much air moves through this facility? NetApp says that if all the air-handling units in the RTP data center were turned on full speed, it could inflate the MetLife blimp in about one second. Its capacity is equivalent to that of a 100-story office building.
The temperature in the second floor is controlled through relief dampers (shown below) that access a side air corridor for waste heat emerging from the first-floor hot aisle. As the hot air rises, it can either exit the building or be introduced into the second floor through the relief dampers.