Comparison of imagined and real behaviors in relation to active coolingmethods under Japanese summer conditions

Recently post-occupancy evaluation is oftenused to know the actual performance of socalledenergy saving building components andto compare with simulated performance. Inreality, the occupants choice how to achievecomfortable conditions, e.g. by switching on anair-conditioning unit or opening a window,influences significantly on the exergy balance ofthe building systems. Measuring the occupants' behavior is cost andtime-consuming so that it would befavorable to use a method of survey alone to enable us to evaluate the occupants' behavior.This would lead to a broader knowledge about the occupants decision process, helping toimprove the above-mentioned choice andthereby to save a significant amount of exergysupplied and consumed for creating comfortablecondition.This paper therefore discusses the reliabilityof the conclusions based on a set of answersfound through a survey and a possibility ofmethod to improve the outcome. The data usedin this paper is from a field study conductedwithin an international student dormitory inTokyo in summer 2007.The occupants behavior was evaluated in twosteps in this field study. First, a written surveyabout current behavior, behavioral backgroundand actual preferences was conducted; this is toknow the "imagined" behavior. Second, theindoor conditions within the rooms of 38students were measured together with theoutdoor condition for six continuous weeksfrom June to August. This allowed the analysisof the "real" behavior. In a first comparison, the "imagined"behavior obtained from the written survey andthe "real" behavior obtained fi-om themeasurement agreed only in around 42% of thecases. Five individual factors: preference;"imagined effectiveness" of passive strategies;knowledge of passive strategies; airconditioningunit usage during childhood; andclimate in the home country were found toinfluence very much on the judgment ofimagined behavior. Taking this intoconsideration, the above percentage increasedup to over 80%.