What is a common sign of a refrigerant leak?

A common sign of a refrigerant leak is frost formation on ductwork. This occurs because the refrigerant is essential for absorbing heat from the indoor air and carrying it outside. When there is a leak, the system loses refrigerant, which can lead to a drop in pressure and a subsequent drop in the refrigerant's boiling point. As the pressure decreases, the refrigerant can evaporate at a lower temperature, causing it to become too cold and leading to frost formation on the evaporator coils or ductwork.

The presence of frost is a clear indicator that the system is not functioning properly, as it suggests that the refrigerant is not circulating effectively. If the refrigerant level continues to drop, it can impair the overall efficiency of the air conditioning system, leading to further issues.

Other signs such as high energy bills or constant compressor cycling may indicate issues with the system's efficiency or performance, but they are not definitive signs of a refrigerant leak like frost formation is. Excessive noise from the unit could stem from a variety of mechanical or operational issues unrelated to refrigerant levels.