Below are white papers describing methods and algorithms on how to calculate power and cooling:
Vendor-proprietary calculators:
HP Power Calculator Utility: a tool for estimating power requirements for HP ProLiant rack-mounted systems
Dell Data Center Capacity Planner (External Link)
IBM System x and BladeCenter Power Configurator (External Link)
Sun SWaP (Space, Watts and Performance) Metric Calculator (External Link)
Want Metrics? - Open Source Enterprise Network Monitoring: Nagios