Effectivity of Different Window Opening States for Single-sided Ventilation: A Monitoring-based Case Study as Data Basis for Simulation Validation

Abstract

The present paper analyses the ventilation effectivity of different window opening settings (single sided ventilation). Results of this study have been generated by monitoring efforts in a test building located in lower Austria. First results from the summer and winter test period in 2024 are presented and used to evaluate the different existing models used in simulation engines for estimation of air change rates of single-sided window ventilation. Such models are regularly used simulations that address indoor thermal comfort, air quality, and building performance. Ventilation is a crucial component in such simulations but only a few studies addressed the validation of ventilation models. Needless to say, aspects of ventilation often are suspected to be the cause of the performance gap between simulation results and reality. A number of standards and recent scientific contributions present various models for the simplified estimation of air changes rates, whereby different sets of input parameters related to room and outdoor conditions are the required input data. The present contribution examines the reliability of calculated air change rates obtained via common estimation methods for the case study room in a test building. Toward this end, a number of tracer gas measurements in a variety of window state /opening settings have been conducted. Moreover, air changes rates have been derived from these measurements (concentration decay of a tracer gas). Based on our experiments, validation and verification efforts of simulation results have been conducted and recommendations toward the most suitable models can be derived from the study.