Paper Conference

Proceedings of ASim Conference 2016: 3rd Asia conference of IBPSA-China, Japan, Korea


System Simulation for Adequate Capacity Design of Multi-split Type Air Conditioner based on Operational Data

Hideki Tanaka, Shigeki Sawamura, Masaya Okumiya

Abstract: Multi-split type air conditioners which have been widely used in Japan, has begun to spread to the world including Asia. The system has advantages such as relatively inexpensive system construction cost and easy-to-use, ease of replacement, etc. On the other hand, the cooling/heating capacity of the system often become excessive capacity from the consideration of large safety factor in its capacity design stage. The excessive system capacity leads to increase of low partial load operation hours responsible for inefficient system operation. On retrofit / renewal of airconditioning equipment in existing buildings, if there is a thermal load and operating data of the previous equipment, the system can be designed along the actual situation and the reduction of air conditioning energy consumption by optimizing the system capacity can be expected. However, the multi-spirit type air conditioner is direct expansion system, is installed a large number of it per building in general. Therefore, it is not easy to grasp the actual thermal load of the building and/or individual rooms. In this paper, by using a utility cost dividing system for multi-sprit type air conditioner in rental office building, energy consumption of the individual air conditioning indoor unit were estimated in order to grasp the actual heat load condition of per room. And an objective system is a gas heat pump type multi-sprit type air conditioner of the agricultural research building. Then the effect of energy saving was analyzed by system simulation software (LCEM tool) using the estimated actual thermal load under the assumption of retrofit / renewal for airconditioning equipment in existing buildings. The results of this simulation for the energy savings from the current situation was that the case of proper capacity repair is 5% reduction, and the case of equipment renewal can be reduced 15% of the operation energy consumption.
Keywords: LCEM (Life cycle Energy Management) tool, Multi-split type air conditioner, Energy conservation, Adequate Capacity Design