Putting an extra fan in my refr cabinet has be on my to do list for a long time. When we first got our SMB I followed the Badger's lead and drilled several holes in the side and top of that cabinet to increase air flow to the back of the refr. I also added some extra insolation. Even with those improvements, the ref cycles to much when is gets up into the 90s.
Here are some pics of the holes I put in the top of the refr cabinet. These holes let the hot air come up and out from back of the refr and then out of the cabinet through a large gap in the back of the cabinet were the window goes below the counter top. I can really feel it coming out of there when it gets warm. But this is still just passive air flow.
The holes on the side, I thought would increase the air flow in. More in means more out.
With my solar panels, I'm not so worried about the power usage but it would be great to have less run time.
I'm looking forward to seeing what kind of improvement this fan gives you. Pushing air or pulling air out, I'm sure will have a bigger effect then passive air flow.
Thanks for the inspiration and video.