Family-owned since 1940, Philadelphia-based Active Radiator manufactures heavy-duty heat exchangers and cooling components for truck fleets, construction and industrial equipment. Its in-house engineers can reverse-engineer obsolete or discontinued parts, while its 141,000-square-foot manufacturing plant and 90,000-square-foot warehouse support both custom production and stocked replacement units. Active also backs its products with cleaning, repair and recoring services through a nationwide distribution network.