Radiator (engine)

An engine radiator is an air-blast heat exchanger that cools the engine coolant by passing it through finned tubes over which a fan draws air, used on small craft and emergency or harbor gensets where no reliable seawater supply exists. It replaces the seawater cooler and sea chest with a closed coolant loop rejecting heat to the air, the same principle as an automotive radiator scaled to the marine diesel. Air cooling caps the heat that can be rejected, so it suits low-power craft and standby sets rather than continuous-duty main engines, which use seawater-cooled or keel-cooled circuits.