The purpose of site environmental control and preparation (that is, for equipment placement, floor layout, airflow delivery requirement, and so on) is to meet the specifications as described in Environmental Requirements. Different data centers may have different arrangements but still meet the same environmental specifications. However, some arrangements are more efficient than others in terms of air conditioning (A/C) capacity usage, A/C operating cost, floor space usage, robustness of hardware equipment during environmental changes, and so on.
The design of the computer room air conditioning units or other environmental control systems must ensure that the cooling air at the inlets of individual chassis enclosures within each hardware cabinet meets the environmental requirements outlined in Environmental Requirements.