What could indicate a refrigerant leak in an HVAC system?

Frost buildup on refrigerant lines is a clear indication of a refrigerant leak in an HVAC system. When refrigerant levels are low due to a leak, the system can experience issues with pressure, leading to the improper temperature changes. As a result, the evaporator coil may not absorb heat effectively, causing the temperature of the refrigerant to drop below freezing. This drop in temperature can lead to moisture from the air condensing and freezing on the refrigerant lines, particularly in low-pressure areas. Observing frost or ice on these lines suggests that the refrigerant cycle is not operating as intended, which is crucial for efficient cooling.

In contrast, increased airflow or higher electrical consumption may indicate other operational issues but are not direct signs of a refrigerant leak. Constant operation of the unit may also arise for various reasons, such as a malfunctioning thermostat, but again does not specifically point to a refrigerant leak. Therefore, frost buildup provides the most concrete evidence related to refrigerant loss in an HVAC system.