Engine room Air Intake/ Ventilation

[PAR]

Michael, I didn't pick on you with my last post on this thread, knowing how you are about things, but you've backed up your misstep with more of the same. If you positively pressurize the compartment, you will (not if, but will) blow fumes and heat into living spaces, unless great extremes are taken to seal the space, which frankly is silly and not especially economical except in ships. A 25' cabin cruiser isn't going to have hermetically sealed engine spaces, therefore you create a low pressure area inside the compartment so any potential for leakage is eliminated, typically being drawn out a duct, from convention or a blower.

[tunnels]

Originally Posted by michael pierzga

General machine room vent system considerations.


http://www.gregorypoole.com/products...ENTILATION.pdf


positive or negative pressure is your choice. Negative pressure is energy intensive for a small craft because it need two blowers..in and out. Positive only one blower.

Also note that you never direct cool air at a hot component or you will raise the temp of the machine room.

Thank you ! thats the most possitive thing i have read for a while and lots to think about !!

[powerabout]

all good stuff
thanks to all

[michael pierzga]

Another detail for ventilation....Make it RAT proof. Very serious damage can be inflicted by rats during winter layup. Design rat proof wire grates for intake and exhaust to protect against these intruders.

[PAR]

Originally Posted by michael pierzga

. . . Make it RAT proof . . . .

Or positively pressurize the compartment and let the fumes forced out, choke them to death.