Yes, getting the heat out from behind the fridge helps in warm weather.
The city water box fan method gets that heat out of the whole van
though, and that is nice in real heat. I did my first one about 25 years
ago when my wife and I first started doing a lot of Baja camping.

Here is a photo of the frozen interior of our stock fridge while camped
on a hot Baja beach after a week. Second photo is of our Syncro camped
there on the trip when the fridge photo was taken.

https://www.thesamba.com/vw/gallery/pix/1237007.jpg

https://www.thesamba.com/vw/gallery/pix/521281.jpg

Mark

Jack R wrote:
> This past winter, I placed a cheap computer cooling fan between the fridge
> cabinet, and the sink cabinet, blowing air across the back of the fridge to
> the normal exhaust.  Simple modification, with the fridge out.  I didn't
> have to cut any cabinets, and easily spliced a switch into the 12v power.
>
> This past weekend, 84 degrees outside, 32 degrees in the fridge.  I had the
> coolest fridge since I've owned my 84 Wolfie, 32 years!  It worked
> wonderful, very little noise and very simple to install.  It actually made
> ice in the ice cube trays!
>
>.......