Consider a home freezer compartment with dimensions of height 30 inches, width 60 inches, and depth 25 inches. Assume heat loss is from the five sides exposed to outside air (i. e. do not consider any heat loss through the bottom surface which the freezer sits on). For a Styrofoam insulation of thermal conductivity 0.025 W/m-K, what should be the minimum thickness of this insulation so that the total heat loss from the freezer compartment is less than 120 W? Assume the freezer air is at -20 C and the inside surface heat transfer coefficient is 5 W/m2-K, while the outside air temperature is 30 C and the outside surface heat transfer coefficient is 20 W/m2K.