We recently bought the 12 volt Endless Breeze Fantastic Fan. I bought it for our boat not thinking I needed it for the B since I had an ocillating fan in the rear that does a great job. However, the Endless Breeze is portable and came in very handy for my daughter sitting in the middle seat when parked at the beach. It has 3 speeds and throws as much air as an A/C box fan. Low amp draw for solar and relatively quiet. A great B accessory for boondocking in the heat or just parking at the beach. One addional note: using a fan with air conditioning makes it much more effective as the air temperature is much more uniform which translates to more efficient cooling with a smaller BTU unit.
I can confirm the Endless Breeze's functionality and versatility. We quite like ours.
I built a "shelf" that spans the "headroom" above the front seats of our PW Lexor. It isn't in the way, and is very handy. I made it so it was removable, but, we've never found we either needed to or wanted to do so.
I then added a "hook" on the underside so, when we stop, I "hang" the fan from the "hook", plug it in to either 12V or a 120/12V portable converter (if we have 120V power), and it is out of our way and very handy.
When we run the A/C, adding the use of the fan really make the A/C seem to work better, less frequently, and the whole inside is more comfy.
When we just run the roof fan, with windows open, we still run the "hanging" fan.