Automatic Pump Down Air Conditioning System for Refrigerant R22 Split Unit

Abstract

Pump down is a process of pumping and storing refrigerant from the air conditioning system into an outdoor unit using a solenoid valve in the liquid line. The conventional method would be to pump down the refrigerant manually before conducting maintenance to the air conditioning system. Industrial refrigeration units use massive amounts of refrigerants. Without a pump down process, the liquid refrigerant would be sucked out from the evaporator and enter the compressor. Compressors do not pump liquid therefore the compressor would be destroyed if a large amount of liquid is found in the compressorhe result shows that 99.98% refrigerant were able to recovered. Hence, this project focused on developing an automatic pump down system. For the purpose of this study, an air conditioning system with 1 horse power (hp) capacity was mounted with two sets of pressure switch and solenoid valve. Once the desired temperature is reached, the thermostat will open and the valve will close. The compressor will then continue to run and evacuate any refrigerant from the solenoid valve’s outlet, including the compressor. The system will continue to pump the remaining refrigerant into the outdoor unit. The whole system will completely shut off after all refrigerants were safely kept inside the outdoor unit. Based on the findings, the process of reducing and controlling refrigerants leakage from the air conditioning system is more efficient and effective when applying pressure of 110 psi.