Units like rooftop systems, split systems, and air handlers have a long service life, while their coils cannot last as long as the units' cabinets. Understanding the symptoms of a defective coil allows facility management to make an informed decision about cleaning, repairing, or changing coils before they ruin the entire unit. This information provides insight into how to identify wear in commercial hvac replacement coils​ and important things to consider before buying new coils.