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

摘要

Recently post-occupancy evaluation is often used to know the actual performance of so-called energy saving building components and to compare with simulated performance. In reality, the occupants choice how to achieve comfortable conditions, e.g. by switching on an air-conditioning unit or opening a window, influences significantly on the exergy balance of the building systems.Measuring the occupants' behavior is cost-and time-consuming so that it would be favorable 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 to improve the above-mentioned choice and thereby to save a significant amount of exergy supplied and consumed for creating comfortable condition.This paper therefore discusses the reliability of the conclusions based on a set of answers found through a survey and a possibility of method to improve the outcome. The data used in this paper is from a field study conducted within an international student dormitory in Tokyo in summer 2007.The occupants behavior was evaluated in two steps in this field study. First, a written survey about current behavior, behavioral background and actual preferences was conducted; this is to know the "imagined" behavior. Second, the indoor conditions within the rooms of 38 students were measured together with the outdoor condition for six continuous weeks from June to August. This allowed the analysis of the "real" behavior.In a first comparison, the "imagined" behavior obtained from the written survey and the "real" behavior obtained from the measurement agreed only in around 42% of the cases. Five individual factors: preference; "imagined effectiveness" of passive strategies; knowledge of passive strategies; air-conditioning unit usage during childhood; and climate in the home country were found to influence very much on the judgment of imagined behavior. Taking this into consideration, the above percentage increased up to over 80%.