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Energy Saver: Refrigerator & Freezer Clean Condenser & Evaporator Coils
Like other refrigerant cycle machines, the heat transfer surfaces of refrigerators and freezers need to be kept clean. If the coils are coated with dust, dirt or anything other than paint that it came with from the factory, the heat transfer efficiency suffers. Find and clean the coils.
The condenser coil on a refrigerator or freezer is usually external and accessible. This coil can be identified as feeling warm to the touch when the refrigerator is running. Some common locations for the condenser coil is on the back of the appliance, underneath the appliance and possibly integral to a side wall. Why manufacturers place them integral to the appliance wall doesn't make energy sense to me but I've seen it done. Fire up your vacuum cleaner with the dusting attachment at least twice a year and clean those coils. For stubborn fouling, use a mild soap-water solution with a bristle brush. Repeat with clean water and bristle brush to rinse the coil off.
The evaporator coil is the other side of the refrigerant cycle. It provides the cold (or more correctly, it moves heat out of the refrigerated compartments.) They need to be kept clean as well. These coils may be hidden in plain sight. I have seen the full gambit of arrangements from aluminum fins (with or without a fan) to coils integrated as the shelving or plate coils lining the inside of the refrigerated compartment. After months of use and no frost free cycle, there may be a big blob of ice that forms on the evaporator coil. That blob of ice is bad. It insulates the heat transfer and the whole refrigerant cycle uses more energy than needed.
A frost free cycle is handy (I admit I have units with it) but it is inefficient never-the-less. Frost free occurs by allowing the evaporator coil to heat up above ...