1. Air Conditioning & Heating Research Laboratory, Matsushita Electric Industrial Co., Ltd., 2-3-1-2 Noji-higashi, Kusatsu City, Shiga 525-8555, Japan, and Environmental and Renewable Energy Systems (ERES), Graduate School of Engineering, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193, Japan