... FN3,FN4 are air cooled heat exchangers for refrigeration system Air cooled condensers-FN-15,FN-18,FN-22,FN25are ... air cooled heat exchangers for refrigeration systemThey are divided in ... 2groups: FN, L.Air cooled condensers-FN-15,FN-18, ... FN-15,FN-18,FN-22,FN25--Air cooled condensers