Refrigerant leakage detection in an EEV installed residential air conditioner with limited sensor installations

Refrigerant leakage is the most frequently found fault in a refrigeration system and efficient detection is highly important. For a sudden leakage, it is relatively easy to detect but slow and long-term leakage is hard to find out, therefore, a useful method for leak detection in such condition is required. Large scale refrigeration systems have abundant data to detect or diagnose leakage. However, in case of small residential air conditioner, installed sensors are mostly temperature sensors, and the number of these sensors is also limited. In this study, a refrigerant leak detection method for an EEV (electronic expansion valve) installed residential air conditioners with limited sensor information is suggested based on experimental data. This method uses temperature differences between inlet air and midpoint of heat exchanger. For various temperature conditions, the temperature difference shows a similar trend which can be utilized as a good leak detection procedure.