I sleep in my trailer so I was looking at 12 volt fans that would be quite.
I found these huge Computer Case fans, they are like 8 inches in dia
(200 MM).
Some claim to be quite.
You might look into this, they need to be mounted but would be far more quite than a bilge pump fan from a Boat.
http://www.newegg.com/Product/ProductList.aspx?N=100007998 600035599&IsNodeId=1&Submit=ENE
I found these huge Computer Case fans, they are like 8 inches in dia
(200 MM).
Some claim to be quite.
You might look into this, they need to be mounted but would be far more quite than a bilge pump fan from a Boat.
http://www.newegg.com/Product/ProductList.aspx?N=100007998 600035599&IsNodeId=1&Submit=ENE