The answer to 'why is my evaporator coil' is that the evaporator coil in your HVAC system is likely dirty or frozen. A dirty evaporator coil can cause reduced airflow, decreased cooling efficiency, and even system failure. Freezing on the evaporator coil is usually caused by low refrigerant levels, a malfunctioning thermostat, or a blocked air filter.
If the evaporator coil is dirty, you may notice warm air coming from your vents, higher energy bills, and reduced cooling power. Freezing on the coil can lead to ice buildup, reduced airflow, and potential compressor damage if not addressed. The solution is to clean the coil or have a professional HVAC technician service the system.