VETUS Louvred Air Suction Vent Type SSV 70

A marine diesel engine needs sufficient air in order to function
correctly. The volume of combustion air required is approximately
6.1m per kW (4.5 m per hp) per hour, based on a maximum air
velocity of 3m/sec.

In addition to combustion air, the engine also requires sufficient
ventilation air to dissipate the radiated heat. The volume of
ventilation air required is about the same as the combustion air
needed.