ASHRAE TC 9.9 has expanded information technology equipment (ITE) air-cooling environmental classes and defined liquid-cooling environmental classes. Additionally, it has provided information necessary to make the critical trade-off decisions between ITE compute performance, ITE reliability, ITE cost, ITE power consumption, and HVAC power consumption. This article discusses two 2011 Thermal Guidelines white papers that provide information to enable more data center operators to achieve significant cooling plant energy savings and lower power usage effectiveness (PUEs).