Infiltration in energy modeling: a simple equation made better

Published

August 8, 2014

Author(s)

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

Abstract

As building envelope performance and HVAC equipment efficiencies continue to be improved to reduce building energy use, a greater percentage of the total energy loss of a building can occur through envelope leakage. Although the energy impacts of unintended infiltration on a commercial building’s energy use can be significant, current energy simulations and building designs generally do not accurately account for envelope infiltration and the impacts of improved airtightness. New strategies to incorporate airflow calculations into building energy calculations have been developed, which are more accurate than current approaches in energy simulation software and easier to apply than multizone airflow modeling (Ng et al. 2014). These new strategies are based on relationships between infiltration rates calculated using multizone airflow models, weather conditions, and building characteristics, including envelope airtightness and HVAC system operation.

Citation

ASHRAE Journal

Volume

56

Issue

7

Pub Type

Journals

Download Paper

Local Download

Citation

Ng, L. , Persily, A. and Emmerich, S. (2014), Infiltration in energy modeling: a simple equation made better, ASHRAE Journal, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916076 (Accessed October 16, 2025)