Being on Lake Michigan and having cooler water, condensation is quite common. I wanted to add some type of ventilation to help with the humidity (I do have 3 damprids hanging in the boat at all times (be careful, they can leak)). I purchased a Marinco Nicor Solar Vent and a spare from WM and borrowed a hole saw from a friend and was ready to go, but I didn't like the idea of drilling a hole in the hatch, which would cost $600 to undo my work.
I decided to go with a computer fan that required no holes. I purchased the following items:
3" Y (W1014) and hose clamp for vacuum systems from Kingspor's Woodworking Shop.
1/4x12x12" pvc from HD.
Noctua NF-A8 FLX computer fan.
Optional:
Multi-functional Timer relay from timers.shop (cycle fan instead of always on).
Micrel LDO MIC2920A-12WT regulator and associated in/out capacitors (protect fan from 14V plus).
Board and box for 12V regulator.
First I removed the port engine vent:
View attachment 181828
Because of vent blower direction, starboard may be better, but port locker has the least amount of natural air flow. I now want to connect the 3" Y to the existing 3 tabbed hole (unmodified & modified):
View attachment 181829
I left 1/4" on the branch for the fan. The locking cuts are for a clockwise turn with the weight of the fan securing it. I then added the 1/4" pvc, which I can't remember if I glued or made them snug to begin with. The round is for added support and the square is for the fan:
View attachment 181830
Installed:
View attachment 181831
12V regulator, capacitors, timer relays and NC relay (one timer relay and NC relay from prior post holding tank vent mod):
View attachment 181833
Box could have been the next size bigger, but I was having trouble finding what I wanted. And this is all installed and ready to go:
View attachment 181832
May not be as ideally situated as a hatch fan, but it is out of the way and I don't have a hatch wart to kick with my toes.