An improved method of modeling infiltration in commercial building energy models

Published

April 28, 2014

Author(s)

Lisa C. Ng, Steven J. Emmerich, Andrew K. Persily

Abstract

As various strategies for improving building envelope and HVAC equipment efficiencies are increasingly used to reduce building energy use, a greater percentage of energy loss can occur through building envelope leakage. Although the energy impacts of unintended infiltration on a building’s energy use can be significant, current energy simulation software and design methods are generally not able to accurately account for envelope infiltration and the impacts of improved airtightness. A new strategy to incorporate airflow calculations into building energy calculations is proposed, which is more accurate than current estimation methods but easier to apply than multizone airflow modeling. This approach is based on relationships between infiltration rates calculated using detailed multizone airflow models and building characteristics, including envelope airtightness, weather conditions and system operation.

Citation

Technical Note (NIST TN) - 1829

Report Number

1829

NIST Pub Series

Technical Note (NIST TN)

Pub Type

NIST Pubs

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DOI Link

Keywords

airtightness, energy, infiltration, modeling, multizone, simulation

Citation

Ng, L. , Emmerich, S. and Persily, A. (2014), An improved method of modeling infiltration in commercial building energy models, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.TN.1829 (Accessed October 17, 2025)