engine air intake

Discussion in 'Diesel Engines' started by nevilleh, Oct 9, 2011.

  1. nevilleh
    Joined: Sep 2008
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    Location: scotland

    nevilleh Junior Member

    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
     
  2. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    It's half square inch per HP for diesels.
     
  4. nevilleh
    Joined: Sep 2008
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    Location: scotland

    nevilleh Junior Member

    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
     
  5. nevilleh
    Joined: Sep 2008
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    Location: scotland

    nevilleh Junior Member

    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
     
  6. michael pierzga
    Joined: Dec 2008
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    Location: spain

    michael pierzga Senior Member

    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.
     
  7. Paul F
    Joined: Sep 2011
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    Location: Norfolk, UK

    Paul F Junior Member

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

    Paul
     

  8. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

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