What might cause low suction pressure, low suction gas superheat, and warm conditioned space temperature in an air conditioning system?

Low suction pressure, low suction gas superheat, and warm conditioned space temperature in an air conditioning system can be primarily attributed to low system airflow. When the airflow across the evaporator coil is insufficient, it results in inadequate heat exchange. This condition means that the refrigerant does not evaporate properly, leading to low suction pressure. As a consequence, the superheat—the difference between the refrigerant's temperature and its boiling point—also decreases since the refrigerant remains in a liquid state longer, failing to absorb enough heat from the indoor environment. The overall result is that the system struggles to cool the space effectively, yielding a warmer conditioned area.

In contrast, while an overcharged system can lead to other refrigerant flow issues, it typically does not solely result in warm conditions due to low airflow. An undersized metering device could restrict refrigerant flow, but it would primarily cause high pressure rather than low suction pressure. Similarly, a dirty condenser would generally lead to high discharge pressure problems rather than directly contributing to the symptoms presented in the question. Therefore, low system airflow accurately encapsulates the issues described, leading to the stated problems in an air conditioning system.