You refrigerator needs regular cleaning. I think at least once a year is recommended. A lot of modern refrigerators have their heat exchanger on the bottom or in another not easily accessible place. I had a hard time cleaning it with the vacuum as the vacuum would not collect any dust and dirt accumulated in farther rows of the heat exchanger.
After trying different things, I stumbled upon the solution - the garden leaf blower! I have an electric blower which somewhat simplifies operating it indoors. Air compressor would also provide adequate replacement but I do not own one.
My first experience with this was not a very good one as we attempted to clean refrigerator without moving it from its usual place. The dust that was in the refrigerator, settled on every surface in our kitchen. We had to completely wash and clean the kitchen after that as well as vacuum adjacent rooms.
Second time I moved refrigerator to the open garage door and blew from inside of the house into the garage. This turned out much better. All I had to do after is to use garden blower inside of the garage to blow out all the dust.
It is OK to use garden blower to clean your refrigerator coils, just make sure to blow towards the outside. Move your appliance to the patio door or garage door so the dust does not fly around the house.
I also found that garden blower can be used to clean out dryer exhaust path from the lint. It works well for this. Disconnect your dryer blow in to the exhaust path. If possible clean outall the lint manually before using your blower.