The cooling operating characteristics of the 3 room air conditioner are experimentally investigated for the number of the indoor units (A, B, C) and the operating conditions (standard, overload) under the cooling operation. The cooling capacity and COP were calculated using a multi-type calorimeter. Also, EEV opening, compressor frequency, and superheat degree were obtained when the compressor started. From the experimental results, we can see that the performance and operation characteristics of the air conditioner depend on the indoor unit operation method. In case of simultaneous and single operation, the cooling overload performance was measured lower than the standard condition. Also, in the overload operation, the power consumption of the compressor was greatly increased and the COP was also decreased.

ABSTRACT
 1. 서 론
 2. 실험장치 및 방법
  2.1 실험장치
  2.2 실험방법
 3. 실험 결과
  3.1 3실(A+B+C) 동시운전 시 성능
  3.2 1실(A, B, C) 단독운전 시 성능
  3.3 3실(A+B+C) 동시운전 시 초기기동 특성
 4. 결 론
 References

• 양동학(Dep. of Mech. Eng., Sunmoon University) | Dong-Hak Yang
• 왕 쩐 후안(Dep. of Mech. Eng., Sunmoon University) | Zhen-Huan Wang
• 권영철(Dep. of Mech. Eng., Sunmoon University) | Young-Chul Kwon Corresponding Author