There is a lot to consider with perforated tiles in data centers and depending on who you talk to you will get different answers. The server floor in a data center is typically built on a raised floor with cold air being pumped under the floor by large CRAH(Computer Room Air Handlers) or CRAC units (Computer Room Air Conditioners). This cold air is flows through the perf tiles and into the data center to cool the load of the heat the servers and other ancillary data center electrical equipment produce. The data center load is a sensible load as data centers do not have a lot of humidity in them from outside sources so the cooling equipment need only be capable of cooling the sensible load with little worry about any latent loads.
With perforated tiles considerations include the amount of CFM’s needed for air flow. The temperature of the air is generally a constant coming from the CRAH or CRAC units. Underfloor pressure control is generally used to meet a specific amount of airflow and the general rule of thumb for airflow on the floor every 1 Kw of server load a data center needs 150 CFM’s of airflow. Thermal imaging is one way to do it although using temperature measurements and graphing these measurements throughout the data center one can determine if this rule meets the requirements for a specific data center and the floor plan. A CFD (Computational Fluid Dynamics) analysis can also be done using specialized software (see video below) to see the output of specific equipment and the best positions for the perforated floor tiles in the data center. From running small experiments (with my limited experience in data centers) I know the position of the perforated tiles can be tweaked to achieve the best temperatures in the cold aisle/hot aisle data center. Perforated tiles too close to the CRAC Units can cause issues with air flow.