Reevaluation of the Gordon-Ng performance models for water-cooled chillers

A careful evaluation of the internal and external predictive ability of the Gordon and Ng (NG) class of models and several of their variants was performed so that any lingering uncertainty can be dispelled. Over 50 chiller data sets from all of the major chiller manufacturers were employed. Chiller types studied include single- and double-stage centrifugal chillers with inlet guide vane and variable-speed drive capacity control, screw, scroll, and reciprocating chillers, as well as two-stage absorption chillers. It was found that the fundamental GN formulation for all types of vapor compression chillers is excellent in terms of its predictive ability, yielding CV values in the range of 2% and 5% comparable to the experimental uncertainty of many chiller performance data sets.