Hi, during last september I've modded my refrigerator with aluminium-styrofoam foil. I've attached the foil between compressor and freezer part. I also added the foil between refrigerator and back coils.
Refrigerator is whirlpool, cca 12 cu ft (220 liters refrigerator and 110 liters freezer). It's rated for 0.9 kWh/day.
Before mod it used 0.9 kWh/day in the summer and 0.45 kWh/d in the winter (both are averages during one week).
After mod it's under 0.4 kWh/day in winter (lowest was 0.35 when wife was away for week :-)) and 0.6 kWh/day in summer (highest 0.75 kWh/day).
I recommend this mod to everyone.