A home made "Power Dorade" solar vent fan

[keneasley]

Felicity is on a mooring in a quiet harbor.

The dorade vent doesn't bring in much air in the sheltered harbor.
I wanted to increase the airflow through the cabin.
I looked into the Marinco and Nicro Solar Vents but I couldn't fit them to my hatches, I didn't want to cut any holes in the boat, and they seemed a bit light on air flow.

So I built a fan that mounts to the ceiling of the boat directly below the hole for the dorade.
The fan pulls air in through the dorade and into the cabin. I connected it to a battery, charge controller, and 50 watt solar panel. It's been running 24/7 since early May! Total cost was about $150.

Overall I'm happy with the set up but after I built the box for the fan I found a similar fan (Vetus) ready-made on eBay for about $75. The Vetus fan is an exhaust fan and looks to have similar air flow and amps to the small computer fan that I used. Using the Vetus fan would have saved some work.
https://www.ebay.com/itm/223283141106? ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649


Some pictures and descriptions follow:

I made the box for the fan out of 4' x 2.5" x 1/2" oak board from Home Depot

Solar_Fan_Box.JPG (1.96 MiB) Viewed 1054 times

The completed set up is shown here. The battery and Charge Controller are mounted in the hanging locker by the head behind the locker door.

Fan from eBay $10 : URBEST 90mm x 25mm DC 12V 2Pin Cooling Fan for Computer Case CPU Cooler 3.5" diameter, 5" diagonal, .2 amps and 30 cfm, which is about 2.5 watts.

Battery from eBay $20 : Mighty Max 12V 9AH SLA Battery

Solar Panel from eBay $45 : 50W Watt Solar Panel Kit Marine

Solar Charger Regulator - Amazon $15 Simlug Adjustable Solar Regulator, 12V 24V Automatic Solar Panel Controller

solar_fan_1.JPG (1.83 MiB) Viewed 1054 times

The solar panel is removed when underway.

Solar_Fan__Solar+Panel.JPG (2.73 MiB) Viewed 1054 times

[keneasley]

Update -

Over the winter I removed the home-made fan and replaced it with the Vetus fan.
Seems like a very good fan so far. Has two speeds, is very quiet, and draws few amps.
It's been running continuously since May.

Solar_Fan_Box_5.JPG (2.1 MiB) Viewed 954 times

[Steve Laume]

Why did you install a dedicated battery, solar panel and charge controller, instead of hooking it up to your house battery?

I bought one of those day and night solar vents and installed it in my forward hatch, years ago. It worked okay for a while and then died. It never did move much air and was not cheap. I like what you did but would probably use the house bank for power. That would create a hot circuit in the boat when everything else was shut down.

I have enough solar panels to handle it, Steve.

[keneasley]

Why did you install a dedicated battery, solar panel and charge controller, instead of hooking it up to your house battery?

I bought one of those day and night solar vents and installed it in my forward hatch, years ago. It worked okay for a while and then died. It never did move much air and was not cheap. I like what you did but would probably use the house bank for power. That would create a hot circuit in the boat when everything else was shut down.

I have enough solar panels to handle it, Steve.

Hi Steve,

Yah, would have been way easier just to connect into the boat's house battery.
I wanted to have a system completely separate from the house and starter batteries.
This way I have no worries about running a fan 24/7 considering my small solar panel.
Someday I'll set up larger solar panels to the starer and house batteries.

The Vetus fan (and my home-made version) is rated to have much more airflow than those solar vents.
After I bought it I learned that it can be set up as intake or exhaust. I set it up as intake since it is below the dorade and so acts to boost the small passive flow from the dorade.

Ken

[keneasley]

I took a different approach this year and removed the dorade box and sealed the hole.
The box was leaking (see earler picture above and note the split in the top of the box).
Removing the box took some effort and I ended up cutting it into pieces.
It was attached to the boat with 4 screws. I sealed up these holes with epoxy putty.
There was a piece of white PVC plumbing pipe "sealed" to the hole with silicone.
The box too was "sealed" to the cabin top with silicone.
I suspect the silicone allowed lots of water to leak in over the years.
I spent some time scraping off the silicone and finally sanding it out of the gelocat with 200 and 400 grit wet sanding paper.
The box was black with mold inside and stunk.
We'll see how this year goes without a dorade.
I do get out to the boat a few times each week and the center drop board has a large vent.
Pictures of what the deck looks like with the wooden dorade box removed.