I have the same sized coke fridge. I only used one strip of 11" heat tape on the left side(I too still have the channel in the middle). With one fan top left blowing air down the heat strip, and the other fan on the bottom right blowing air up circulating the air counter clockwise. I used water bottles lined against back of each level and my temps stay with in 0.5 degrees. I have used this incubator for the last few years with out any issues or adjustments. At the least I would add some water bottles as it will help steady your temps especially when you open the door.