engine air intake

Hi all,

Just a simple question about engine room vent intakes.

The rule of thumb used to be 1 square inch per 1 horsepower.

Can anyone tell me if this is correct and what manufacturers require?

This would bethe vent area cut in deck / hatches for inboard diesel engines.


Thanks

Neville

 

This document contains a general discussion of engine room venting.

Be aware that on a boat you may have other considerations... air breathing generator or additional heat generating machinery like battery charger or inverter banks installed in the engine room so be conservative when specing your system


http://www.gregorypoole.com/product...ments/LEBW4971-02 ENGINE ROOM VENTILATION.pdf

 

It's half square inch per HP for diesels.

 

Hi Gonzo,

Thanks, that makes me feel better, I guess I should get it in writing from the manufacturers . Just had a few tales from fishermen that were getting me worried.

Regards

Neville

 

Michael,

Thanks for that. The document suggests that it may be worthwhile for us to consider forced ventilation as I am aware that our cramped engine rooms together with fairly large fast revving engine are quite hot relying on only natural draft ventilation from the apertures in the deck hatches above.

More investigation needed!

Regards
Neville, Scotland

 

If its a simple boat...use simple solutions.

If the machine room is more complex, get your fingers working and research available documents on the web.

Heat is destructive to machine room equipment. Plenty of fresh air when under operation and at rest is needed. Good circulation of this air in the machine room is important.

 

Thanks for that link Michael, it's luck that my son just got his degree in maths to help me understand it !!

Paul

 

The half inch formula is for air intake. Ventilation to keep the engineroom cool may need more .