<![CDATA[This study analyzes the cooling performance degradation of a Modena MD 20W freezer box utilizing R134a refrigerant. The primary issues identified include continuous compressor operation, failure to achieve the target temperature of −18°C, and low discharge pressure. This research aims to analyze discharge pressure as a primary diagnostic indicator and investigate its relationship with the freezer compartment temperature. A descriptive-analytical case study method was employed, with data recorded at 25-minute intervals over 200 minutes. Measurements were conducted using a manifold gauge, digital thermometer, and clamp meter across three distinct conditions: utilizing a QD52H compressor, a Highly C-BF053L4A compressor under no-load conditions, and under a 15 kg beef load condition. The results indicated that the QD52H compressor only generated a discharge pressure of 86–110 psig (well below the normal range of 145–185 psig), yielding a freezer temperature of 12.0°C and a cooling rate of 0.084°C/min. Following replacement with the High-efficiency compressor, the discharge pressure increased to 128–145 psig, the temperature reached −20.7°C, and the cooling rate improved by 192.86% to 0.246°C/min. Under the 7 -hour beef load test, the freezer wall temperature reached −20.0°C with a core beef temperature of −2.0°C. This study concludes that discharge pressure analysis is a reliable, effective, and non-destructive diagnostic method. ]]>
