What might a suction line temperature of 73°F indicate if the suction pressure is at 15 PSIG?

A suction line temperature of 73°F with a corresponding suction pressure of 15 PSIG may indicate a system undercharged condition. In a properly charged system, the expected suction line temperature should align with the saturation temperature corresponding to the suction pressure.

Using typical refrigerant properties, the saturation temperature for 15 PSIG is significantly lower than 73°F. A suction temperature that is higher than expected suggests that the refrigerant is not present in sufficient quantity to absorb heat effectively, resulting in a higher temperature at the suction line. This scenario implies that the system lacks the necessary refrigerant, leading to lower efficiency and potentially causing performance issues.

When the system is undercharged, it cannot adequately absorb heat, leading to higher temperatures in the suction line. This condition can place the compressor at risk of damage if not addressed promptly, making it essential for HVAC technicians to monitor suction pressures and temperatures to maintain system integrity and efficiency.