As the use of underfloor air distribution (UFAD) systems increases,so does the importance of effective operation and maintenance (O&M) of these systems after installation. As UFAD technology is applied, designers, technicians, facility managers, and building owners or their representatives all need to know how to ensure that these often mission-critical systems operate as intended. This guide supplements UFAD Guide: Design, Construction and Operation of Underfloor Air Distribution Systems, providing specific, practical advice beyond design, construction, and startup into successful ongoing operation and maintenance. Installers, technicians, and building owners will find this booklet a valuable resource for getting the most out of their UFAD systems and maintaining those systems’ useful lives.