Engine room blower

[medsailor1]

Hi fitting a blower in the engine room , is it best to fit it so it blow air in or suck hot air out

[sailormed]

Suck out hot air from the top of the engine room.

edit: just saw your username :-)

[Shenandoah52]

You didn't say gas or diesel but if it is gas you want the intake of the blower in the low point of the engine compartment because gas fumes are heavier than the air (air+gas=heavier) and you want to be able to extract that air to the outside so you help eliminate the possibility of an explosive condition. If it's diesel and you want to remove the hot air that rises to the top of the compartment then put it near the top of the engine compartment like sailormed said.

[wingless]

My gasoline engine boat has both.

The factory installed the blowers sucking from the lowest point below each engine.

One of my modifications was to add thermostatically-controlled blowers sucking from above the fuel rail. This was my 100% effective solution to eliminate heat-soak vapor lock that would prevent restart after dropping anchor for an hour in tropic temperature water / air environment.

The only issue is if both engines are running (drawing air), the OEM blowers are running and my heat exhaust are all running at the same time, then my hull will implode like an egg shell.