ESCO Air Conditioning Practice Exam 2025 – Complete Study Resource

The symptoms of a dirty evaporator in an air conditioning system can indeed lead to high suction pressure and high discharge pressure. When the evaporator coil becomes dirty, it restricts the airflow over the coil, preventing proper heat exchange. This results in reduced cooling efficiency, causing the refrigerant to not absorb enough heat from the indoor air. As a consequence, the pressure in the evaporator (suction side) can increase because the refrigerant is not evaporating properly.

Additionally, the increased load on the compressor attempts to compensate for the lack of cooling, which can lead to higher discharge pressure. This situation can cause the compressor to work harder, potentially leading to overheating or increased wear over time. Therefore, high suction and discharge pressures are indicative of a cooling system's struggle due to a dirty evaporator.