The purpose of this study is to clarify the definition and concept of Net Escape Velocity (NEV), conceptually proposed by Prof. Mats Sandberg, as a new index for ventilation effectiveness in an indoor environment. The previous paper (part 1) presented the definition of NEV (the transported velocity of a contaminant for defining the convection flux and diffusion flux) on the premise of computational fluid dynamics simulations and proposed a calculation method for NEV using enclosed simple space. In addition, the relationship between NEV and the Local Purging Flow Rate (the ventilation rate for defining the averaged concentration of a domain) was presented. This paper presents the analysis results of NEV and Local Purging Flow Rate based on the flow field and diffusion field in the IEA Annex20 two-dimensional benchmark test case (three-dimensional space). The possibility of NEV as the index for evaluating the structure of a non-uniform concentration field of the contaminant is revealed.