Corrosion is the most significant danger for these AC units. Over a period, the condenser coil suffers from corrosion then it needs replacement or repairs. To resolve this problem, companies use Gold or Blue Fin method. They paint the condenser tubes with special anti-corrosive paint. This improves or extends the life of the AC unit. The only difference between Blue Fin and Gold Fin technology is that Gold Fin technique doesn’t rust easily. Further, this technology is expensive as compared to Blue Fin.