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Ventilation Rates in U.S. Office BuildingsFrom the EPA Base Study



Andrew K. Persily, J Gorfain, Greg Brunner


The EPA BASE study involved indoor environmental measurements in 100 U.S. office buildings. This paper presents an analysis of the measured outdoor air ventilation rates, including comparisons with the requirements in ASHRAE Standard 62. The outdoor ventilation rates measured using duct traverses at the air handler intakes are higher than might be expected, with a mean value of about 50 L/s per person. However, these elevated values are not so unexpected given the low occupant density (mean of about 3.5 persons per 100 m2) and the high outdoor air fractions (mean of about 40 %). Air change rates based on peak carbon dioxide concentrations in the space are lower than the volumetric values with a mean of about 20 L/s per person. Questions exist regarding the reliability of these peak CO2 values based on the validity of the assumptions on which the determinations are based.
Proceedings Title
Indoor Air 2005
Conference Dates
September 4-9, 2005
Conference Location
Conference Title
Proceeding of the 10th International conference on Indoor Air and Climate


carbon dioxide, database, measurement, office buildings, ventilation


Persily, A. , Gorfain, J. and Brunner, G. (2005), Ventilation Rates in U.S. Office BuildingsFrom the EPA Base Study, Indoor Air 2005, Beijing, -1, [online], (Accessed June 15, 2024)


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Created September 1, 2005, Updated February 19, 2017