High CFM 12v Hatch Fans?

[mrmrsk]

I have a 32ft Sailing Monohull. Looking to add some serious hatch fans that can operate on 12v. I've chartered a bunch and all the cabin fans I've ever seen, even on newer boats, are junk so I'm not even sure if the current draw at 12v is just too high for typical systems? Physically, I'm imagining a pop-up hatch with a centrifugal-style brushless ~direct-drive fan. This would keep rain out and keep the profile compact. It would also continue to operate as a regular hatch that opens all the way. An alternative design might be 4 smaller centrifugal blower-style fans, but that seems like a less efficient use of space. This might belong in some general engineering forum too, for how to size the fan motor and some maker forum for where to source such a fan assembly, but because of the unique challenges of marine equipment, I am starting here. Anyone have success with buying or making excellent hatch fans with high throughput/cfm? My hatches seem like they could easily accommodate a 16" diameter fan.

Note, even a 120v box fan (with a very poor fit/seal to the hatch hole) isn't as strong as I would expect. Perhaps a tighter seal of a final product would make a big difference.

If a box fan draws 100 watts at 120v, that's 0.83333 amps. So for 12v equivalent that'd be like 8.333 amps on full speed. And I have two hatches, so 17amps draw - and that seems well within the capabilities of typical house batteries, right? Also, box fan blades are bigger than my hatches, so the numbers would be less. Why can't I find any larger 12v dc fans, let alone those with centrifugal blades?

I'm sure someone has been down this road before. What did you learn?

[Bowdrie]

Check out Newark.
This link will give you over 1,200 fans to choose from, and that is just the 12VDC fans, some as big as 280mm.
I'm not sure any outfit on earth has the selection they do.


https://www.newark.com/c/cooling-the...oltage-vdc=12v