What are the six common causes of evaporator freezing?

An evaporator coil freezes due to specific disruptions in heat transfer or system pressure, with six primary culprits standing out as the most frequent triggers. First, restricted airflow caused by severely clogged air filters, dirty blower wheels, or crushed ductwork starves the coil of the warm air it needs to stay above freezing. Second, low refrigerant levels resulting from a puncture or loose service valve create a severe pressure drop, causing the remaining refrigerant temperature to plummet drastically. Third, mechanical failures such as a weak blower capacitor, a failing blower motor, or a malfunctioning fan belt can cause the indoor fan to spin too slowly to move adequate air across the coil. Fourth, dirty or dust-coated evaporator fins act as a thermal barrier, preventing efficient heat absorption from the household air. Fifth, blocked or closed supply and return registers across your living spaces disrupt the proper pressure balance and airflow dynamics required for steady operation. Sixth, running the air conditioner during unusually cool outdoor weather, such as chilly spring or autumn nights, can cause system pressures to drop and trigger unintended freeze cycles.