Lawrence Berkeley National Laboratory

The typical U.S. household uses two to four times as much electricity per person as the typical Japanese household. Differences in space conditioning drive this disparity, in part. Several key differences are identified. Japanese homes have one-third the square footage, while heating and cooling strategies are more localized and more active. In addition, cultural norms and expectations regarding thermal comfort play a key role. In Japan, the range of acceptable temperatures is wider than the U.S., and is higher in summer and lower in winter. The authors argue suggests that thermal comfort is more conditionally defined in Japan, relative to the season, social norms, and other factors, whereas it is a more fixed concept in the U.S. Meanwhile, electricity use from air conditioning (AC) is now significant and rising in both countries. Researchers ran a pair of interventions to encourage passive cooling strategies and reduced AC use in an American community of zero energy buildings and a Japanese “smart home” community, both of which had identified AC use as an obstacle to reaching sustainability objectives. The interventions utilized behavioral levers such as commitments, goal setting, consumption feedback, reminders, and social norms. Both experiments induced modest increases in the use of passive cooling strategies. Japanese participants’ electricity use from AC dropped by 7%, while American participants’ remained unchanged. Cross-cultural comparisons of cooling strategies deepen our understanding of occupant behavior within the broader social context and indicate the “social potential” for energy conservation that could be tapped if alternatives to AC were viewed through that lens.