If you have a small air compressor or other machine in your workshop that vibrates, you can dampen it by putting special foot pads of corrugated cardboard squares under each of the legs. Make the pads about 2 in. thick by gluing several squares together. Glue so the corrugation of one piece lies at right angles to that of the next square of cardboard.
Move your refrigerator out from the wall and vacuum its condenser coils once a year unless you have a no-clean condenser model. Your refrigerator will run for shorter periods with clean coils.