i would first triple check all your insulation. I had an issue when I first ran my keg box b/c there was one area that looked insulated but leaked cool air. If you know someone with an infrared thermometer those things will find the hot spots and help you save ripping the bar apart. i built a triple keg box (yes I went overboard) and it holds 38 degrees on medium setting on the 2.7 haier firdge. I have 2 fans in ice box, 2 in keg box circulating, and then 2 on coils and 2 more on compressor (not counting fan on power supply). I hope it saves my fridge a littel bit and keeps my b eer cold.
best of luck!