CFD解析に基づく各種室内空間の有効換気容積: 室内換気性状の評価指標としての有効換気容積の定義と算定法（第2報）

摘要

本研究では、室内空気が完全混合状態でない空間の換気性状を表 す指標のひとつである「有効換気容積」について検討を行う。前報（第 1報）では有効換気容積を『室容積のうち、有効に換気がなされて いる領域の容積』と定義し、この算定方法を示した。また、有効換 気容積を求める際の視点の違いにより使い分ける重み関数について 述べ、例として3種類の重み関数を示した。%It is very important to keep indoor air quality good in order to avoid health problems such as Sick House Syndrome occurred in Japan. It is also very important to ventilate indoor spaces efficiently to reduce energy consumption and CO_2 emission. Ventilation efficiency indexes have been proposed as means to evaluate the efficiency of ventilation systems and these indexes have been taken into account in ventilation design. The previous paper proposed the effective ventilated volume, hereafter EVV, as a ventilation efficiency index and showed a definition of EVV based on the volume integral with a weighting function. The meaning of EVV depends on the selected weighting function, therefore three types of weighting function were examined. In this paper, several case studies on the EVV based on computation fluid dynamics (CFD) are demonstrated. In the cases of office models and factory models, mixing ventilation and displacement ventilation are compared with EVV results. In the house kitchen models, the ventilation efficiency is examined with various positions of supply opening of outdoor air. In the house models, two conditions are studied. EVV is evaluated when 24 hour ventilation system is operated and when the kitchen exhaust system is operated. In the clean room models, the position of exhaust openings is examined. When the exhaust openings are installed at ceiling, calculated EVV is much higher than that in the case of wall exhaust openings.