I have one of the Snyder's kits and it does work well. It consists of a PVC gutter which spans the cooling fins with a muffin fan mounted below it blowing up. It is thermally switched and fused. It is effective and has lowered my fridge temps considerably. On the highest cooling setting the fridge compartment has had temps as low as 29f this summer. That said, I am concerned that if the fan fails, all airflow will be blocked over the cooling fins. Because of this concern, I am going to remove it and place a larger fan just under the roof vent.
Craig and Carol
1997 34' Excella 1000
1970 27' Overlander, International
2009 Ford F150 5.4L
ProPride hitch with 1400# bars
Past President Southeastern Camping Unit (12)