Engine compartment forced ventilation?

[Petar]

I own an 1986 Freedom 36 which has originally fitted Yanmar 3GM30F in what appears very confined and closed compartment which I find well insulated (heat and noise). Front engine access is through rather large cover under the companionway stairs which provides reasonable access for maintenance and inspection. Through the Port aft locker space there is back access to that space for cooling water intake valve and gearbox oil change as well as drive shaft dripless seal, exhaust etc. On the back of that there is a round hole with a fan and ducting which wasn't in use when I purchased the boat. My question is whether that fan is to supply the fresh air to the engine compartment or to extract the heat from the engine compartment? Apart from that opening (for the fan) and several holes for passing the battery cables there is no direct supply of air to the engine but i have not observed any problems with the engine running. Any thoughts?

[JimsCAL]

The enigne box for the 3GM30F in my Cal 33-2 is fed with two large (5-6 inch) ventilation hoses that terminate in cowls on the transom. Always thought this was a great arrangement.

[Faster]

Beneteau provides a ventilation fan that runs when the engine is running.. I think it's a great idea that will reduce heat buildup and odours. You might want to put that back in service.

[Capt Len]

Diesel require a lot air just to breath let alone cool the engine compartment.Deal with it.