The huge weight of a refrigerator comes from a number of parts. First is the raw size of this major appliance. Full sized models are up to 70 inches (almost 6 feet) tall. Then you have the insulated walls. These are super thick and the heavy insulation within them (often a rigid polyurethane foam). Then the mechanical components (refrigerant, compressor, coils, etc) make up a good bulk of weight. And finally, there’s any containers inside. Not to mention a fridge full of food!