Japanese residential air-conditioning: natural cooling and intelligent systems☆

Abstract Japanese residential heap pumps (which commonly combine cooling, dehumidifying and heating in a single system) are unlike American room air conditioners in a variety of ways. A key to the difference follows from the traditional Japanese focus on heating or cooling persons rather than spaces. When this focus is coupled with the widespread use of inverter technology, solid-state electronics, Japanese cultural norms, the constraints of house form, and the islands' climate, the result is a sophisticated system unlike anything available elsewhere. In addition to a large number of standard remote-control options, some Japanese systems can perceive and learn user preferences, while others can generate pre-recorded and algorithmic fluctuations of wind and temperature. We discuss some of the implications (both for users and for energy consumption) of these innovations. We also consider the results of a small survey of Japanese air-conditioner owners in which we found that despite the sophistication of their heat pump systems a significant majority prefers natural cooling. Most, for example, open windows and pursue other natural cooling strategies before using their air conditioners. While they view the devices as urban necessities, they also report limited knowledge of their machines' advanced features. This research examines the design, cultural context and use of Japanese air-conditioning systems, along with some of the behavioral and theoretical issues raised by their unique form. After discussing traditional Japanese housing and heating and cooling technologies, we describe contemporary Japanese heating/ cooling systems, speculate about the differences between US and Japanese systems, and present preliminary findings on Japanese cooling behavior from a small sample of Japanese air-conditioner owners.