The use of raised-floor grommets to prevent bypass air from escaping the underfloor plenum is a well-known airflow management best practice. Elimination of bypass airflow improves the cooling capacity and efficiency of any data center. Despite this, best practices are often not followed. Grommets are not installed for long periods after operation begins and usually not until there is a desire to increase capacity or reduce operating costs. Designing and specifying grommets in the construction documents so they are installed during the initial construction, or expansion, of the data center helps to ensure the facility performs as intended from the moment the data center goes live so that PUE goals are met, and operating costs are minimized.