If you simply replace the solar vent with a newer style unit that does have a battery, it will help keep the interior fresh 24/7.
Dorades are a delight in hot breezy places where even with a bug screen good air flow can be had,
I install them with a 6 inch plastic deck plate inside and out.
Should the unit be swept , the deck can be sealed.
In winter sealing both ends of the thru deck tube and stuffing some foam in the tube will help with heating.
We also cut the center of a deck plate out and hot glue in a 12v computer fan.
These only work in one direction so a pair is needed if you also want to push air out.
Installing a 24v computer fan reduces the air volume and sound , so it can be directly over a bunk with no hassle.