As we have seen, “green computing” refers to environmentally sustainable Information and Communications Technology (ICT) technologies and operations. Recognizing that networks and data centers support mission-critical computing and connectivity functions essential to U.S. economic, scientific, and technological organizations, one still must note that these assets consume relatively large amounts of energy. The energy is consumed not only to operate computer systems, servers, and networking equipment such as switches, routers, firewalls, repeaters, and transmission gear, but also to operate air-conditioning systems, fire-suppression systems, redundant and backup power supplies, and perimeter security systems. To that end, planners need to apply Best Practices, which allow organizations to improve overall efficiency. Analytical methods (and tools) to model energy management and heat disposition in data centers and telecom nodes are still complex and costly. Therefore, common-sense and heuristic techniques are often employed to achieve efficiency improvements.