This European Standard is applicable to non-ducted unit air coolers for refrigeration operating: a) with direct dry expansion of a refrigerant; b) with liquid overfeed by pump circulation of a refrigerant; c) with a coolant. This standard specifies uniform methods of performance assessment to test and ascertain the following: - product identification; - standard capacity; - standard coolant pressure drop; - standard refrigerant pressure drop (for operation with liquid overfeed by pump circulation only); - nominal air flow rate; - nominal fan power. This standard does not cover evaluation of conformity. It is not applicable to air coolers for duct mounting or with natural air convection. This European Standard does not cover technical safety aspects. This document (FprEN 328:2014) has been prepared by Technical Committee CEN/TC 110 "Heat exchangers" with German collaboration, the secretariat of which is held by DIN (Germany). The responsible German body involved is Working Committee NA 044-00-11 AA "Kälte-Apparate" ("Refrigeration machinery") at DIN Standards Committee Refrigeration Technology (FNKä).