Investigation of CO2 tracer gas-based calibration of multi-zone airflow models

Steven C. Snyder, T. Agami Reddy, William P. Bahnfleth

Research output: Chapter in Book/Report/Conference proceedingConference contribution


This paper proposes a methodology to calibrate multizone airflow models in existing buildings. The methodology has been demonstrated with the widely used multi-zone model CONTAM and applied to two buildings, one synthetic and one actual. The methodology builds on previous workwith thecalibration process enhanced by the use of carbon dioxide tracer gas test data. A key concept highlighted in this paper is that calibration of airflow models is a highly over-parameterized problem and that some form of model reduction is imperative. This is achieved by performing an airflow-based sensitivity analysis to identify influential system drivers, a tracer gasbased sensitivity analysis to identify macro-zones (i.e. groups of rooms that can be combined into one zone for the purposes of predicting or studying dynamic airflow behavior under different types of stimuli), and finally, a process of tuning the model parameters. It is found that for mechanically ventilated commercial buildings, calibrating multi-zone models by reconciling differences between measured and predicted tracer gas behavior is more strongly impacted by those factors which significantly influence room air change rates than by airflow path leakage parameter tuning.

Original languageEnglish (US)
Title of host publicationASHRAE Transactions - ASHRAE Annual Conference
Number of pages13
EditionPART 2
ISBN (Print)9781936504350
StatePublished - 2012
Event2012 ASHRAE Annual Conference - San Antonio, TX, United States
Duration: Jun 23 2012Jun 27 2012

Publication series

NameASHRAE Transactions
NumberPART 2
ISSN (Print)0001-2505


Other2012 ASHRAE Annual Conference
Country/TerritoryUnited States
CitySan Antonio, TX

All Science Journal Classification (ASJC) codes

  • Building and Construction
  • Mechanical Engineering


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