Weather-driven infiltration and interzonal airflow in a multifamily high-rise building: Dwelling infiltration distribution

As multifamily high-rise buildings have various infiltration and interzonal airflow distributions caused by wind and stack interactions, dwelling infiltration from the outdoor air and interzonal airflow varies depending on the floor and direction. Thus, the different infiltration is one of major factors on the indoor air or energy demand loads of dwelling units in the buildings. This study characterizes dwelling infiltration distributions in multifamily high-rise buildings that accounts for infiltration and interzonal airflow, which are caused by the interactions of stack and wind effects. To do so, typical reference choices were determined for the building, annual weather conditions, leakage area levels, and analysis methods. The infiltration and interzonal airflow were characterized by season, floor, household (or direction), and leakage level. While past studies largely ignored the contribution of interzonal airflow, this paper demonstrates here that this contribution is predominant (about 80%) and exhibits significant variation between floors. Finally, this study finds that infiltration rates by household and interzonal airflow differences by floor should be addressed more carefully for annual dwelling infiltration distributions. In addition, three leakage relationships are defined by air driving forces (stack and/or wind effects) and household locations in terms of the annual dwelling infiltration distribution. Considering the leakage area of household entrance door is emphasized for dwelling infiltration. Based on the leakage level of household entrance, interesting airflow features, such as wind-driven interzonal airflow or wind-driven infiltration on upper floors under the strong stack effect, are observed.