Studies on leak conditions of refrigerant-gas from multiple air-conditioning systems

Safety design of multi-air-conditioning-system was studied. Leakance of refrigerant gas by the leak accident during several different conditions was evaluated in an experimental system. Leakance from the liquid pipe was largest when the air conditioning system was working as heating. Using this experimental data, gas concentration in the room was predicted. As the result, it was found that maximum reached concentration in the room became larger than limit concentration defined by oxygen deprivation limit. For the countermeasure, separation of the room from leak point using air-tight ceiling system was found effective to reduce the concentration in the room. As the result of the prediction, concentration in the room was reduced as about 1/10 of concentration in the plenum chamber, if the countermeasure was evaluated.