Without proper monthly maintenance, it is possible. Cool Release, proprietary water treatment system, works to prevent the small amounts of calcium, lime, or rust that can buildup on the coils. Although the water from the nozzles evaporates almost immediately, in certain climates, some wetness may reach the coils. Just to be safe, it is always a good idea to spray down the outside of your condenser monthly with a 50/50 mixture of water and white vinegar, and rinse it off. This is a good maintenance idea with or without the Cool-n-Save system attached.