You are correct. If your refrigerator vents out the top. The fans should be mounted to direct air to the top. Either mounted on the vent cover pulling air in or place in a way to direct air up. Side vented fridge is where you would place the fans on the top vent directing air out. Of course on a side vented setup you could also place a fan on the bottom forcing air up also. More important for side vented setups are getting the hot air out. My fridge came with a fan on the coils directing heat up. I only have fans forcing air out the top vent.
