Engine room ventilation

[incognito]

I had a bit of a problem with my engine, so got the engine expert down on Saturday to have a look.
In the event, he suddenly turned round and pointed out that the well insulated (noise and fire) 'engine room' had no ventilation.
I thought about this a bit, and came to the conclusion that engine rooms generally do not have ventilation - am I wrong? Is there any way of letting a draught through that will not let water in?

 

[billmacfarlane]

I'm not quite sure what he means by that. Presumably you've got a diesel engine in the compartment, which needs air to run, so you must have some ventilation.

 

[snooks]

For every gallon of diesel used, the engine uses something stupid like 12,000 gallons of air!...so yup, you do need ventilation...Some sort of fan ventilation is a good place to start, something that will suck air into the compartment and pump the hot air out, (diesels don't like hot air either)...a vent on the transom? depending on the style and age of your yacht

 

[incognito]

Bill, my engine must suck air in from the bilges and then exhausts in the usual way, but there is no general ventilation of/for the engine ROOM.

 

[Guest]

In my previous boat, a Finngulf 391, there were ventilation ducts from the engine room to the big cockpit locker. That locker again had an air inlet in a compartment which could not easily be flooded. Benefits: when running the engine you automatically ventilate the locker to prevent build-up of moisture. Also the risk of flooding the engine room is minimal as any water getting into the locker will go down into the bilges. A bit like a huge Dorade, isn't it ?

Andreas

 

[Guest]

What size engine and what sort of craft? If you are talking about a small yacht auxiliary [my guess it is?] then it would be a good idea to have ventilation but not compulsory! But to settle the issue, after the negine has been running for about 30 mins and set at a stable rpm then open th eengine room and let it have some fresh air - if your rpm rises then it would probably be a good idea! Also, stick an air thermometer in there and look at the temp before and after the above!