"Sustainable design@ global warming@ depleting fuel reserves@ energy use@ and operating cost are becoming increasingly more important. These issues are even more important in datacom equipment centers for reasons such as the following: ? Large@ concentrated use of energy (can be 100 times the watts per square foot of an office building). ? Operations running 24 hours@ 7 days a week@ have about 3 times the annual operating hours as other commercial properties. The intent of this publication@ as part of the ongoing ASHRAE Datacom Series@ is to provide the reader with detailed information on the design of datacom facilities that will aid in minimizing the life-cycle cost@ and to maximize energy efficiency in a facility to align with ASHRAE's stated direction (from the 2006 Strategic Plan) to ""lead the advancement of sustainable building design and operations."""