Vents... Dehumidifier... ???

Aug 23, 2014
164
Catalina 310 Guntersville, Alabama
I had a cruising sailboat back in the early 90's... 30' Islander. We installed exhaust fans and vents to help keep the fresh air moving below in hopes to combat the mildew and stuffy smell.

I now once again own a sailboat... Catalina 310. Other than the hatch under the starboard cockpit seat... there are no vents or exhaust fans. When I search on the forum I see a lot about using dehumidifiers and not as much about installing vents and such.

Your thoughts? Thanks.
 
Aug 23, 2014
164
Catalina 310 Guntersville, Alabama
We are in Alabama... and the boat goes for 2-3 weeks without a visit.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,746
CAL 35 Cruiser #21 moored EVERETT WA
You need to have vents to exchange the outside air for the interior air or you will have an issue with condensation in the boat and you will get mold/mildew growth. Hard to believe the Cat310 doesn't have vents. Look into a couple of dorade boxes
upload_2017-4-30_16-39-47.png

to give your boat that salty look and fresh air in the cabin. The dorade keeps the water out but lets the fresh air in.
 
Aug 30, 2009
17
Oday 19 Trailerable
At the very least a battery/solar vent such as Nicro vents let into the fore hatch set to exhaust and another aft set to intake will make a large difference in your boat. On my old O'day 28 I had those and one other in the main cabin overhead in the wet, rainy climate of Astoria OR and had no issues with condensation, mildew. It takes a bit of work, but it works.
 

Bradv

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Jul 30, 2016
20
Hunter 31 Lewis and Clark Lake
This summer I'm installing a hatch cover that has a residential through-wall exhaust fan built into it. Will run it during the week while at dock and idle. Trying to overcome some old boat smells and I believe that this will be a game changer. Nothing else I've done with dorado vents or other means has made a big difference. HOpefully you have power at the dock and can take advantage of that.
 
Dec 13, 2010
123
Hake 32RK Red Bank
On my last boat an O'day 30 I installed a solar vent fan in the forward hatch plexiglass cover. It worked wonders and ran pretty much 24/7 even in storage.
My current boat has two dorades one port one stbd pointed different directions and works perfectly well.
 

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,744
Hunter 430 Waveland, MS
using dehumidifiers
You will be well ahead with one in the Humid south. Even with vents, they would have to be powered to provide enough air flow to prevent mildew.
Remember with powered vents, there must be an air exhaust to have circulation.
Jim...
 

pateco

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Aug 12, 2014
2,207
Hunter 31 (1983) Pompano Beach FL
Has anyone added solar fans to their dorades? I am thinking about some 12V computer fans in the interior of the dorade box wired to a small panel on the outside of the box.
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
In the aft cabin of my B323, there is an access hatch to under the transom. I found that taking the little hatch board out, then opening the lazz lid, a lot of air flows in through the bunk. YMMV.

I also want to put some kind of vent in some location of the head to help vent the head when the door is closed.
 
Aug 23, 2014
164
Catalina 310 Guntersville, Alabama
In the aft cabin of my B323, there is an access hatch to under the transom. I found that taking the little hatch board out, then opening the lazz lid, a lot of air flows in through the bunk. YMMV.

I also want to put some kind of vent in some location of the head to help vent the head when the door is closed.
I too have an access door into the transom area from the aft cabin... thanks for the idea. I could install a louvered vent in the access door. this would help a lot. Then with an exhaust fan in the forward hatch I should be able to get some air moving.
Thanks.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,746
CAL 35 Cruiser #21 moored EVERETT WA
No fan in my dorades, but I did find this interesting dorade design on a couple of large European made boats. I bought a couple and plan to add them this year to my boat.
3704517190_d4d2f91129_m.jpg 7583447582_8354c4da96_m.jpg 8205898459_9d480c3b64.jpg
 
May 24, 2010
2
Hunter 376 Deale, MD
I have used 2 solar powered Nicro vents on a Hunter 35.5, one through the coach and one through a forward hatch. One set to intake, one set to exhaust and it worked well. I believe there was an option to put a lid/blank cover for heavy weather sailing which was not necessary on the Chesapeake. To my understanding, the idea is to keep the outside and inside temps and humidity levels the same to prevent condensation.
 
Sep 20, 2016
26
Hunter 240 Holland, MI
I did have a powered vent system in my last boat. It was a 110V computer fan that was really quiet. It drew air in through a vent in the companion way washboards and blew it out through a dorade on the deck. The trick is to have a screen on the intake so it doesn't suck bugs in! Don't forget, you will need to make the screen very easy to clean because it will suck in all kinds of airborne fuzzies and pollen as well.
IMG_0753.JPG IMG_0648.jpg IMG_0646.jpg
I was worried about pulling cold damp air into the boat when evening came around, so I simply connected the fan to a timer and ran it from just after sunset till just before sundown.
It worked excellent.
 
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pateco

.
Aug 12, 2014
2,207
Hunter 31 (1983) Pompano Beach FL
I did have a powered vent system in my last boat. It was a 110V computer fan that was really quiet. It drew air in through a vent in the companion way washboards and blew it out through a dorade on the deck. The trick is to have a screen on the intake so it doesn't suck bugs in! Don't forget, you will need to make the screen very easy to clean because it will suck in all kinds of airborne fuzzies and pollen as well.
I was worried about pulling cold damp air into the boat when evening came around, so I simply connected the fan to a timer and ran it from just after sunset till just before sundown.
It worked excellent.
I was going to go 12V fan(s), located in the dorade box, and powered by solar only, so they would only run during daylight hours.
 

pateco

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Aug 12, 2014
2,207
Hunter 31 (1983) Pompano Beach FL
What do you guys do with your dorades if you have Air Conditioning onboard? Do you seal them off?
 

JRT

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Feb 14, 2017
2,054
Catalina 310 211 Lake Guntersville, AL
I was told to leave a 60 watt bulb on inside my cabin buy the locals at Lake Guntersville. Only had the boat, O'day 25, a few months seems to work.

BTW I'm at North Alabama Sailing Marina, where are you?
 
Aug 23, 2014
164
Catalina 310 Guntersville, Alabama
Our boat is at Ditto Landing right now but we live on Seibold Creek just a couple miles from you in the Riverbend subdivision. Nice to meet a neighbor!
 

JRT

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Feb 14, 2017
2,054
Catalina 310 211 Lake Guntersville, AL
Nice, we drive by your boat every weekend heading to the lake!
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
If you have a dodger, you might try some vent into thr head? Depending on whether ou have or leave a Bimini, you could try replacing part of the companionway drop boards if your slip is oriented to keep rain out. (Save the solid drop boards for storm conditions.)

I avoid letting water get to the fusions or fabric.

You could get more aggressive with a stern vent and duct....but I'd not go there.