Direction of cowl vent
- Thread starter kpgraci
- Start date
- Status
Cowl vent: fore or aft
It depends of the wave-height... I've had several gallons dumped on a settee; luckily someone was sleeping on it and we immediately went forward to turn the vent 180°.
Otherwise, the air flow in the boat should be from the forepeak to the companionway (that dodger is a huge cowl vent pulling everything it's way) and from the aft cabin to the companionway... The forward cowl is more efficient facing forward.
Pierre le Caboteur
It depends of the wave-height... I've had several gallons dumped on a settee; luckily someone was sleeping on it and we immediately went forward to turn the vent 180°.
Otherwise, the air flow in the boat should be from the forepeak to the companionway (that dodger is a huge cowl vent pulling everything it's way) and from the aft cabin to the companionway... The forward cowl is more efficient facing forward.
Pierre le Caboteur
Re: Cowl vent: fore or aft
I always face the cowls aft when underway, even in flat water, because we have commercial traffic wakes that can put water over the bow anytime. I face em forward when anchored. when its really snotty out, I repace them with the pop-in covers.
I always face the cowls aft when underway, even in flat water, because we have commercial traffic wakes that can put water over the bow anytime. I face em forward when anchored. when its really snotty out, I repace them with the pop-in covers.
Cowl-vent directions
If it's in a self-draining anchor locker it will work as a Dorade box so you can aim it ahead and it will 'flush out' the anchor locker with seawater every time! Other than that, aim it away from the prevailing weather and let it work as an exhaust vent.
On Diana I have a Dorade box in the cockpit. One cowl is for the fumes blower-- that aims aft and is covered with a drawstring for when the boat is moored. The other is for the vent hose that empties into the foot of the quarter berth. That one faces forward. The solar-powered exhaust vent is on the foredeck hatch. So there is a (gentle) draft from stern to bow.
I elected to not have a cowl vent on deck for the rode locker (there isn't room). I would have made a 'Myth of Malham' vent out of it (having slotted vents in the hull at the top of the rode locker and a drain in the stem at the bottom of it) but the door opening into the v-berth scared me with the possibility of a wave flooding the boat. So that locker 'breathes' through a vent in that door.
If it's in a self-draining anchor locker it will work as a Dorade box so you can aim it ahead and it will 'flush out' the anchor locker with seawater every time! Other than that, aim it away from the prevailing weather and let it work as an exhaust vent.
On Diana I have a Dorade box in the cockpit. One cowl is for the fumes blower-- that aims aft and is covered with a drawstring for when the boat is moored. The other is for the vent hose that empties into the foot of the quarter berth. That one faces forward. The solar-powered exhaust vent is on the foredeck hatch. So there is a (gentle) draft from stern to bow.
I elected to not have a cowl vent on deck for the rode locker (there isn't room). I would have made a 'Myth of Malham' vent out of it (having slotted vents in the hull at the top of the rode locker and a drain in the stem at the bottom of it) but the door opening into the v-berth scared me with the possibility of a wave flooding the boat. So that locker 'breathes' through a vent in that door.
considering anchor lockers open via doors into the forepeak of many boats, the opening forward on a passage is not appropriate. even with a self bailing anchor locker. big seas do damage and are strong. the small boats i used to have with cowls on the bow got the cowls turned away from the seas. safer that way.
my larger boats--i have a 35 and a 41--neither has a cowl on the bow--i believe that is a special privilege saved for the smaller day sailors. the cowl vents on my formosa are in the shower stall and one over the bed in the master stateroom. they are turned forward for ventilation. proper venting in a boat is from bow to stern. keeps the air movement appropriate--the engine is in the rear so is inappropriate to vent from stern to bow--breathe in the exhaust--even if the gods are in a perverse mood and send teh breezes from the stern when the tides are against the winds... i also have 2 deck plates on my lazarette..but they donot have cowlings.
they wont. there is enough air flow in this boat to be comfortable and stink-free..LOL....no diesel smell no kat smell no problem. opening ports are a blessing..kat lives on the roof for potty time ...under way he gets the shower stall and a special lil door for him
my ericson doesnt have cabin top cowls
only has cowls astern for the engine air intake.......i face them forwards to get max flow for the diesel......
my larger boats--i have a 35 and a 41--neither has a cowl on the bow--i believe that is a special privilege saved for the smaller day sailors. the cowl vents on my formosa are in the shower stall and one over the bed in the master stateroom. they are turned forward for ventilation. proper venting in a boat is from bow to stern. keeps the air movement appropriate--the engine is in the rear so is inappropriate to vent from stern to bow--breathe in the exhaust--even if the gods are in a perverse mood and send teh breezes from the stern when the tides are against the winds... i also have 2 deck plates on my lazarette..but they donot have cowlings.
they wont. there is enough air flow in this boat to be comfortable and stink-free..LOL....no diesel smell no kat smell no problem. opening ports are a blessing..kat lives on the roof for potty time ...under way he gets the shower stall and a special lil door for him
my ericson doesnt have cabin top cowls
only has cowls astern for the engine air intake.......i face them forwards to get max flow for the diesel......
- Status