Improve ventilation

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Joined: 4/26/17
Posts: 42
Improve ventilation

I am wondering what approaches people have used to improve ventilation when the boat is closed up. There are two solar vents in the salon, but that doesn't do much and does nothing for moving air through the boat. I really need to do something to improve this situation. 

Bob Longo
Transcendent, 1993 Catalina 36 Mk. 1.5, hull 1237
Raleigh, NC

pkeyser's picture
Joined: 5/18/13
Posts: 585

Check your hatch latches. If they are like ours, they have a feature that locks them open about a half inch. It has made a tremendous difference with our boat. If we expect heavy winds and rain, we will close the hatches all the way. Under moderate rain/wind conditions, we get no water in the boat.

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

GaryB's picture
Joined: 10/26/08
Posts: 556

My boat spends the summer on a mooring. I have the dorades facing forward allowing air to enter the boat from the direction of the wind. I have a solar vent in the hatch over the head drawing air out. I use a SS hook and eye door hook to hold the head door open approximately 3" when not on board. This seems to ventilate the boat reasonably well. If on a slip I suspect I would need to have the dorades set for whatever the prevailing wind direction is.

Gary Bain
S/V "Gone With The Wind"
Catalina 36', Hull #: 1056, Year: 1990, Engine: M-35
Standard Rig
Moored: Boothbay Harbor, Maine
Home: Auburn, Maine

Haro's picture
Joined: 11/7/14
Posts: 364

Bob - I installed 4 12VDC 3 1/2" computer cooling fans on a 1/4" starboard and covered the 4" holes with window screen to block insects from coming in. They are held in the hatch just above the galley stove and the hatch is ajar. The 4 fans are powered by a 12VDC adaptor that is plugged in to the electrical outlet nearby. I am docked in a slip with shore power. I leave the V birth and the head hatches ajar. It provides air circulation 24hours a day with not much moisture inside.
This can only be done if you are plugged into a shore power.

KevinLenard's picture
Joined: 1/28/15
Posts: 201

Note that many people reason that their dorade air funnels both need to 'face the direction of the wind' to maximize the volume of air being forced into the interior, however if the boat is mostly airtight then this actually hinders air flow.  By turning them 180 degrees from each other, no matter what direction the wind is blowing the cowling facing (more or less) the wind will take air in, while the one facing downwind will have lower pressure and will create a vacuum effect at the upwind-facing dorade and will most effectively draw air in and then out if both are equally open.  Counter-intuitive, but scientifically more effective.

Kevin Lenard
'91 C-36 Mk. "1.5" Tall Rig, Fin Keel, Hull #1120, Universal M-35 original (not "A" or "B")
CBYC, Scarborough, Lake Ontario, Canada

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