I figured out a decent way to clean the condenser coils on my KitchenAide refrigerator (refrigerators are one of the biggest users of electricity in the house, and dust covered condenser coils drastically reduce the efficiency of the refrigerator).
The coils on this particular refrigerator are on the underside of the refrigerator with only a narrow slot in at the front to access them. My canister vacuum cleaner attachment is too broad to fit well.
So, I used my air compressor and air nozzle on the left side opening to "blast" the dust off the coils while running the vacuum cleaner with an open end on the pipe at the same time on the right side opening.
The air compressor cleaned the coils beautifully while the vacuum cleaner running at the same time sucked in almost all of the dust blown off by the compressor. Without the vacuum running concurrently, the kitchen would have been a cloud of dust and dirt.
I should have thought of this years ago....