The Microelectronics and Emerging Technologies Thermal Laboratory (METTL) at Georgia Tech houses fabrication and characterization facilities, as well as experimental rigs for the study of heat transfer and fluid flow phenomena from tens of nm to approximately m length scales. Characterization equipment includes infra-red microscopy, particle image velocimetry, high speed imaging, and temperature, pressure, and flow rate measurement capabilities over a broad range. Fabrication capabilities include wafer dicing, wire bonding, and nano-fabrication. Experiments at the rack level are performed at the Consortium for Energy Efficient Thermal Management (CEETHERM) Data Center Laboratory, which accommodates 28 computing racks arranged in a typical hot aisle cold aisle configuration.
The data center infrastructure is designed to handle power densities of 500 W/sq.ft. Six computer room air conditioning units (CRAC) supply a total of 79,000 CFM of air, which provides cooling to the data center. A variety of cooling arrangements (under floor and overhead distribution) can be achieved with the four down flow and two up flow CRAC units. In addition, the facility has two air economizers that draw in cold ambient air during winter to reduce the cooling load on the chilled water system. In the economizer mode, the facility's digital control system performs a series of psychometric calculations to check if the conditions are conducive and accordingly commands the exhaust and economizer fans to draw in outside air. Power for the data center comes from a 480V, 1200A grid supply. The grid power branches into two panels that independently distribute power to the computing and cooling infrastructure in the data center.
The power for the computing equipment is fed though three power distribution units that step down the voltage from 480V to 210V to power up the rack power strips. The data center has power monitoring capability installed at various levels from the incoming grid supply to the rack power strips. The data from the power meters and other data acquisition systems in the facility is logged into the PI software to generate PUE charts.
Another major feature of the facility is the ability to conduct controlled studies (which usually cannot be performed in a large data center) in a simulated data center environment and compare it with an existing data center facility. This is achieved by splitting the facility into two equal sections using a collapsible insulted partition. The control system is designed such that each half has its own independent power monitoring, air flow distribution and economizer controls. This arrangement offers flexibility to validate the computational models and test the control algorithms on a smaller scale.
Investigations of server chip level thermal management advances are performed through access to a companion laboratory, which houses experimental rigs for the study of heat transfer and fluid flow phenomena from tens of nm to approximately m length scales. Characterization equipment includes infra-red microscopy, particle image velocimetry, high speed imaging and temperature, pressure and flow rate measurement capabilities over a broad range. Fabrication capabilities include wafer dicing, wire bonding and nano-fabrication.
