Air Conditioning Repair Certification (ETI) Practice Exam

A common sign of low refrigerant levels in an AC system is frost build-up on the coils. When there is insufficient refrigerant, the pressure in the system drops, leading to lower temperatures in the evaporator coils. This causes moisture in the air to freeze on the coils, resulting in frost or ice accumulation. As the frost builds up, it can block airflow, further impeding the system’s ability to cool effectively.

Recognizing frost build-up is crucial for diagnosing refrigerant-related issues, as it can also lead to compressor damage if not addressed. Proper refrigerant levels are essential for an air conditioning system to function efficiently. When refrigerant levels are low, the system can't absorb the heat effectively, leading to a series of performance issues that can exacerbate the problem if not corrected.