Your air conditioner might be freezing up due to the following reasons.
Inadequate airflow due to damaged ducts can result in condensation and ice formation.
Dirty air filters also block air circulation, forming ice on the evaporator coil when no air passes through it.
When your air conditioner has low levels of refrigerant or refrigerant leaks, the condensed water will freeze over the coil, forming ice.
A faulty blower fan and motor will obstruct the airflow resulting in frozen coils.
A clogged drainage line could result in drip tray overflow and freeze the moisture over the evaporator coil.