Generally speaking, as life expectancy of air-conditioning systems is shorter than building structures, we have to carry out remodeling project several times for them during endurance period of buildings. Dealing with remodeling plan, we have to take actual building usage into consideration in remodeling plan and design appropriately from the point of further reduction of carbon dioxide emission or energy saving. In this paper, results of investigation study are shown. It was found that operational state of newly installed system is vastly improved in comparison with former system.
