The hybrid cooling system of vapor compression system and naturally circulating coolin system using R-410a for indoor mobil tele-communication center(IMTC) is developed and its performance is experimentally studied. Its results are summarized as follows. First, cooling capacity of naturally circulating cooling system is proportional to indoor and outdoor temperature difference and it has max. 4,550 kcal/h at indoor and outdoor air temperature difference 15℃. Second, heat exchangers of evaporator and condenser should be designed and constructed to be able to get maximum refrigerant capacity by naturally circulating force and to enhance heat transfer by refrigerant. Third, cooling capacity of hybrid cooling system has optimum operating point according to refrigerant charging capacity and refrigerant charging capacity of naturally circulating cooling system is 30~50% more than vapor compression refrigeration system.

Abstract
 1. 서 론
 2. 연구 내용
  2.1 에너지 절약형 냉방기
  2.2 에너지 절약형 냉방기의 구성 및 제어 알고리즘
  2.3 실험방법 및 결과
 3. 결 론
 참 고 문 헌

• 김영득(인덕대학 기계자동차과 교수) | Y. D. KIM
• 이성제(인덕대학 에너지환경연구소 연구원) | S. J. LE
• 이주성(인덕대학 에너지환경연구소 연구원) | J. S. LEE
• 나도백(한국과학기술정보연구원) | D. B. NAH