Data center classification Tier Level Requirements Single non-redundant distribution path serving the IT equipment 1 Non-redundant capacity components Basic site infrastructure guaranteeing 99.671% availability Fulfils all Tier 1 requirements Redundant site infrastructure capacity components guaranteeing 99.741% availability Fulfils all Tier 1 Tier 2 requirements Multiple independent distribution paths serving the IT equipment 3 .All IT equipment must be dual-powered and fully compatible with the topology of a site's architecture Concurrently maintainable site infrastructure guaranteeing 99.982% availability .Fulfils all Tier 1, Tier 2 and Tier 3 requirements All cooling equipment is independently dual-powered, including chillers and Heating, Ventilating and Air Conditioning(HVAC) systems Fault tolerant site infrastructure with electrical power storage and distribution facilities guaranteeing 99.995% availability 2021/2/8Data center classification Tier Level Requirements 1 •Single non-redundant distribution path serving the IT equipment •Non-redundant capacity components •Basic site infrastructure guaranteeing 99.671% availability 2 •Fulfils all Tier 1 requirements •Redundant site infrastructure capacity components guaranteeing 99.741% availability 3 •Fulfils all Tier 1 & Tier 2 requirements •Multiple independent distribution paths serving the IT equipment •All IT equipment must be dual-powered and fully compatible with the topology of a site's architecture •Concurrently maintainable site infrastructure guaranteeing 99.982% availability 4 •Fulfils all Tier 1, Tier 2 and Tier 3 requirements •All cooling equipment is independently dual-powered, including chillers and Heating, Ventilating and Air Conditioning (HVAC) systems •Fault tolerant site infrastructure with electrical power storage and distribution facilities guaranteeing 99.995% availability 2021/2/8 7