GB - Ventilation

[Mac G]

Am curious what other GB owners do to provide passive ventilation when boat is closed up.
On sailboat had dorades and scoops and washboard lourvers and all manner of getting fresh air below and flowing thru the vessel without electricity and without leaving the place unsecured and unlocked.
Am considering some places where I will add solar powered vents (e.g. in forward hatch and aft companionway) but am curious what other GB owners do.
Other than leaving windows open what do you do to promote air flow thru the boat when you are absent and she is locked up?
Please advise
Thank you

 

[Comodave]

I have used 2 solar powered vents to promote ventilation. I put one in the forward cabin hatch putting air into the boat and one in the aft cabin pulling air out of the boat.

 

[Serene]

When in the marina and the boat is on shorepower and locked up I use a dehumidifier on a timer so it runs between 10am and 4pm daily (hottest part of the day).

Not the same I know, but it does keep the interior fresh and dry.

 

[Choices]

I use a carpet drying fan, mounted in the bow that blows the length of the boat.

If no power crack engine room hatches and let air circulate.

 

[Nick F]

I leave the windows open in the two heads.

 

[Mac G]

I leave the windows open in the two heads.

Do you get rain below if it is stormy weather?
How do you prevent that?

Am thinking of adding solar power vent to hatch in forepeak set on "in" (like Dave suggested above) and then maybe add a good old-fashioned dorado box and high vent on the aft cabin house between the aft companionway and the area where the dingy is stored with scoop facing aft to suck air out.

But still toying with other ideas.

This is another area that surprises me about the GBs which are otherwise really well made and well thought out vessels - they suck when it comes to passive interior ventilation unless you leave windows open.

Am used to sailboats with lots of vents and am shocked how closed-up this boat is by design.

 

[Nick F]

Do you get rain below if it is stormy weather?
How do you prevent that?

.

I have bug screens on the outside. These substantially limit the amount of rain that comes in through the small head windows.

 

[Old Sea Dog]

On ours there is a solar fan on forward hatch that pulls air out. And while not "daisy fresh", there is enough air that comes in from the aft cabin companion way even with a canvas cover on it.

 

[Caballero II]

Am curious what other GB owners do to provide passive ventilation when boat is closed up.
On sailboat had dorades and scoops and washboard lourvers and all manner of getting fresh air below and flowing thru the vessel without electricity and without leaving the place unsecured and unlocked.
Am considering some places where I will add solar powered vents (e.g. in forward hatch and aft companionway) but am curious what other GB owners do.
Other than leaving windows open what do you do to promote air flow thru the boat when you are absent and she is locked up?
Please advise
Thank you

Yeah, in SoCal, cracking the forward helm window and the aft saloon window about 1" is sufficient. Not sure that will work for you. Also, we are on our boat nearly every day and open things up as needed. If needed, I would have put a dehumidifier and a fan onboard at the dock with 110 V., but we just haven't needed to do so. Dorades might have been kinda nice for the forward and aft staterooms, but adding them would have you need to mess with the headliner.

 

[Xlantic]

I leave the windows open in the two heads.

This is what I do.

 

[JP2]

What model and size?
If you have the Lumar(sp?) forward hatch, it usually has 2 locking positions; closed completely and open about 1/4 - 1/2" on 3 sides. It will not leak in the 2nd position and because none of the doors (or aft cabin hatch doors in a Classic) are anywhere near tight, you have plenty of air moving, especially in a breeze. A fabric hatch cover obscures the small opening to any observer.

 

[mbdana]

GB Ventilation

We usually crack the forward hatch an 1" or two, no so much the rain would come in. Mostly push open the center windshield window a bit and open the rear facing saloon window ( upper deck overhang above it), neither will take rain. Vents to engine room do ventilated at a certain level of convection air movement or lift the smaller sole hatch...with a note on the door(s) so you will remember.
MDana
Third Reef
36' Grand Banks Classic #819
Potts Harbor Maine (South Harpswell)

 

[Mac G]

There are times when I want the vessel locked up tight and everything closed. And other times we do not want to leave anything even open a crack if expecting high winds with heavy rain. But in all instances would prefer to have some air flow or at least the possibility of some air flow.
So am considering a solar powered vent in the forward hatch set to draw air in, and then an old school dorade and scoop vent on the aft cabin house combined with louver vents in the aft companionway doors.
All the doors between the forepeak and aft cabin remain open so that would get air flow thru entire vessel.
As pointed out, engine room has its own separate ventilation that is always there.
Don't like leaving that middle forward pilot house window open as have had wind driven rain enter there before.
Thank you all for your comments and advice.

 

[Mambo42]

From April until mid November we are always on the boat, so then ventilation is not a problem.
In winter time I just put a dehumidifier in the galley, open up all the drawers, cupboards etc and set the dehumidifier to 45 %. The drain goes into the sink and I just let it run 24/7. As soon as it reaches the required level it will switch off and it will switch itself on again when humidity increases.

 

[Capn Bob]

On my previous boat, the PO had drilled a hole in the plexiglass lens of the forward hatch and mounted a Nicro Solarvent in the hole. Definitely helped ventilation, but;

1. Rain always found its way in;
2 Green water over the bow would totally soak the v-berth, and
3. Eventually the plexiglass lens split at the hole. Had to replace the lens

I never liked this idea, and it had only caused me lots of problems (and mold!). Drilled through the cabin top over the head and mounted it there. Problem solved: now any water entering the fan drained into the shower sump