The answer to 'evaporator coil freezing up' is that a frozen evaporator coil is a common issue in HVAC systems that can be caused by a variety of factors, including low refrigerant levels, airflow restrictions, and thermostat problems. Symptoms include reduced airflow, poor cooling performance, and ice buildup on the coil.
Some potential solutions include checking the air filter, clearing any blockages, adjusting the thermostat, and recharging the refrigerant. However, if the issue persists or you are unsure of the cause, it's best to call a professional HVAC technician to diagnose and repair the problem.