The blowers should be wired to start when the engines do and stay on for 15 minutes or so after shut down that will cool the engine room much faster than by passive ventilation.
Boat engine room vents.
In the ideal installation inlet air will be ducted into the engineroom low near the sole and away from heat sources while exhaust air will be drawn from the top of the space directly over heat producers such as engines.
One specifically for marine use is blue sea s atd automatic timer disconnect.
Marine air flow is an australian company that specialises in engine room ventilation equipment for vessels of all sizes and operating conditions.
Delta t systems engineered ventilation solutions increase vessel and engine efficiency and save money through reduced fuel consumption and overhaul expenses on board commercial military and pleasure vessels alike.
Ventilation system components manufactured by delta t systems include marine grade axial fans rated and standard fire dampers moisture eliminating air intake filters as well as automatic and manual engine room ventilation control systems.
A time delay relay will do this automatically.
It is important that these systems are designed and installed to minimize the possibility of water intrusion.
Forced ventilation should include both inlet supply and exhaust air.
Having the correct ventilation setup will ensure better operating costs conditions and an extended lifespan of your equipment.
Boat engine blowers are a great place to start since they are made to push a huge amount of air out of the engine room but it can also help to position boat engine vents in strategic locations to help cool the engine room off after the boat has arrived at its destination.
Engine air intake vents.
Many power boats feature a ducted system to moves fresh air from outside the hull through louvered grills dorade boxes air duct hoses and then directly to engine air intakes.