This paper presents a means to quantify air flow performance of both traditional raised floor designs and non-raised floor air-conditioning designs for data centers. Metrics are developed that will readily permit owners, engineers and operators to measure and quantify the effectiveness of their data center cooling systems or changes that they make to their cooling systems to increase air cooling efficiency. The metrics incorporate and integrate together the major factors that decrease the effectiveness of computer room air cooling. These factors, which are covered in the paper, include; negative pressure flow rate (air induced into the floor void), bypass flow rate (from floor void directly back to the air-conditioners without cooling servers), recirculation flow rate (from server outlet, back into server inlet) and the balance of CRAC and server design flow rates. Examples of the application of these metrics are also presented.

Units: Dual