Air Conditioning Repair Certification (ETI) Practice Exam

The sweating liquid line at the filter drier indicates that the system is starved for refrigerant. When there is insufficient refrigerant in the system, it leads to inadequate absorption of heat in the evaporator coil. This situation causes the liquid refrigerant to not fully vaporize, resulting in lower than normal pressures. As a consequence, the liquid refrigerant does not absorb enough heat to raise its temperature sufficiently, and this leaves the line cooler than usual, which can lead to condensation forming on the line.

In order to maintain proper cooling performance, the balance of refrigerant within the system must be optimal. The sweating on the liquid line serves as an indicator that the refrigeration cycle is not functioning effectively, with insufficient refrigerant flow contributing to the cooling issues.

Understanding the signs of refrigerant starvation is crucial for diagnostics in air conditioning repair, ensuring that technicians can pinpoint problems accurately and resolve them effectively.