We installed our first 3" Nicro Day/Night Plus vent in a small hatch
in the forward head
. That way if water
gets in, it will be minimal damage. We just prop the door opened when needed. We might put a vent in the door this winter.
The 3" and 4" vents have the same housing size. They have different hole sizes for the fan (3" and 4"). It was a tight fit to be sure we could still move the handle to open the hatch
. We used a hole saw of the correct size. It is secured with machine screws and nylock nuts. We used silicon to seal. The instructions say that you can use an adhesive
to secure and not use machine screws. We chose to do something less permanent in case we have to replace it - some posters here or other forum questioned the durability of the Nicro vents. You also have to be careful of the type of sealant
. The wrong type will eat into either the housing or the hatch acrylic
- I forget which. The instructions have the details.
We really wanted to put the bigger vent in our main hatch, which is over our V-berth bed
, but weren't confident of how water
tight it would be. So far so good, but we haven't had any big water over the deck
since installing. We may add a second in another small hatch that is in the V Berth cabin
that would result in fewer issues if it leaks
If you chose this vent, watch out for the little o-rings used to seal the screws holding the cover over the solar
panel in place. You'll know what I mean when you get to this step. The instructions warn you as well. They are little buggers to find if you don't see them pop out.
Somewhere there are recommendations for how often you should change the air in 24 hours. As I recall
, when I did the calculation for our Beneteau
423, I think two 3" or 4" vents were about right. We have dorades as well so don't really need both 3" vents.