In this study, the initial operation characteristics of a multi-type cooling system with three indoor units using an inverter compressor were investigated experimentally using a calorimeter. The operating characteristics of the cooling system were confirmed under the full load condition of simultaneous operation of three rooms and the partial load condition of individual operation of two or one room under the standard cooling conditions. The capacities of A, B and C are 50, 20, and 30% of the total capacity, respectively. The 3 room combination has 100% capacity, the 2 room combination has 50, 70 and 80% capacity, and the 1 room has 20, 30, and 50% capacity. The compressor condensing and evaporating pressures, the electronic expansion valve openings of indoor units A, B, and C, and the compressor operating frequencies were measured for 10 minutes after the cooling system was started. During the initial operation, the changes in the operating time and opening of the electronic expansion valve varied depending on the indoor unit combination and the operating load, and the relationship between the compressor pressure and the operating frequency was found.

Abstract
1. 서 론
2. 실험방법 및 장치
3. 실험 결과
    3.1 실내기 3실 동시운전 시
    3.2 실내기 2실 조합 운전 시
    3.3 실내기 1실 운전 시
4. 결 론
References

• 이창수(Department of Mechanical Engineering, Sunmoon University, Graduated student) | Chang Soo Lee
• 권영철(Department of Mechanical Engineering, Sunmoon University) | Young Chul Kwon Corresponding author