This proposed revision of ASHRAE Standard 151 updates the 2002 edition to include recent developments in TAB technology and practices and to address the types of equipment and systems found onboard ships today. It updates the field testing procedures for air, hydronic, refrigeration, and control systems; updates the instrumentation to be used in testing; and revises the reporting methods to be used. The standard is intended to provide valuable information for evaluating the performance of shipboard HVAC&R systems.