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Evaluating Ventilation Performance



Andrew K. Persily


The evaluation of building ventilation performance is critical to understanding indoor contaminant transport dynamics and interpreting indoor contaminant measurements. However, ventilation performance involves many different issues and metrics that can make such evaluations challenging. Also, many indoor air quality research studies have not included adequate evaluation of building ventilation and its impacts on indoor contaminant concentrations. There are several reasons for this history of neglect; they include the complexity of ventilation, the cost associated with the measurements, and the lack of guidance on how to conduct such evaluations. This chapter explains what is involved in evaluating and understanding ventilation performance in buildings, with a focus on the parameters involved, how building configuration and ventilation system type impact how such evaluations are conducted, and the connection between the reasons for ventilation evaluations and the strategies employed. Among the ventilation performance parameters that are covered are whole building outdoor air change rates, ventilation system outdoor air and supply air delivery rates, and envelope infiltration rates. Some of the key points stressed in this chapter include the following: actual ventilation performance often does not match design intent; ventilation rates vary significantly with weather and system operation and therefore a single value is not particularly useful without information on the conditions during the measurement; multiple repeated measurements under different conditions are required in order to fully understand ventilation in a building; and, while indoor carbon dioxide concentrations can be a useful tool in evaluating ventilation, its application is based on multiple assumptions that must be valid.
Handbook of Indoor Air Quality
Publisher Info
Springer Singapore, Singapore,


airflow, building performance, indoor air quality, infiltration, ventilation


Persily, A. (2022), Evaluating Ventilation Performance, Handbook of Indoor Air Quality, Springer Singapore, Singapore, , [online],, (Accessed April 22, 2024)
Created January 3, 2022, Updated November 29, 2022