Indoor air pollution in office buildings in mega-cities: Effects of filtration efficiency and outdoor air ventilation rates

Tianchen Ruan, Donghyun Rim

Research output: Contribution to journalArticle

6 Scopus citations


Building systems play a critical role in determining indoor concentrations of pollutants of outdoor origin in polluted cities. The objective of this study is to investigate impacts of outdoor ventilation flow rates and filter efficiencies on indoor concentrations of PM2.5 and ozone for office buildings in two mega-cities: Los Angeles and Beijing. Using the U.S. Department of Energy medium office building model, parametric analysis was performed to examine indoor pollutant concentrations under varied filter configurations, ventilation modes and outdoor concentrations. The results show that for office buildings located in polluted cities, two-filter (air handling unit filter and outdoor air filter) systems are more resilient to outdoor PM2.5 pollution than single filter (air handling unit filter only) systems, especially when outdoor ventilation air flow rate is high due to economizer ventilation or dedicated outdoor air systems. However, for ozone removal, adding an outdoor filter makes a marginal difference. The study results also suggest that during extreme outdoor pollution events in mega-cities such as Los Angeles and Beijing, high efficiency filters (>MERV 11) and reduced flow rates (<8.5 L/s per person) should be used to limit indoor PM2.5 concentration below 35 μg/m3.

Original languageEnglish (US)
Article number101609
JournalSustainable Cities and Society
StatePublished - Aug 2019


All Science Journal Classification (ASJC) codes

  • Geography, Planning and Development
  • Civil and Structural Engineering
  • Renewable Energy, Sustainability and the Environment
  • Transportation

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