I installed four small computer fans to the inside of the lower cover to the back of the refrigerator compartment, using nylon ties. I installed an inline switch and normally turned the power on only when it is going to be over 70 during the day. The fans seem to have improved efficiency considerably.
I would assume installing the larger computer type fans on the top of the frig near the roof vent would be more efficient, but what I did just looked easier.
My fans were left over from computers I scraped out, but I would assume any computer supply business would have fans at a reasonable price. If not, try e-bay.
