May 8-9, 2018 | Salt Lake City, UT
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The Addition of Moisture Transport to the Air Leakage Energy Calculator

Tuesday, May 8, 11:00 – 11:45

In 2016-17, Oak Ridge National Laboratory (ORNL), the National Institute of Standards and Technology (NIST), the Air Barrier Association of America (ABAA), and the US-China Clean Energy Research Center for Building Energy Efficiency (CERC BEE) collaborated to develop an online calculator that accurately estimates the energy savings that could be expected if an air barrier system was added to the building envelope wall design.  The tool is free to the public, user-friendly, and uses the simulation results of the best-in-class building energy simulation tool EnergyPlus and the whole building airflow simulation tool CONTAM.  This tool is available at

Another benefit of deploying an air barrier is that the reduced amount of airflow through the wall will decrease the amount of water vapor carried in the air and through the building envelope.  These envelopes will enjoy improved durability because of the reduction in moisture transport.  The purpose of this study is to extend the web-based energy savings calculator for air tightness to include the moisture transport across the building envelope component as a function of airtightness for a family of commercial buildings in climates across the continental United States and Canada.  In this presentation, we will demonstrate the capabilities of this new tool.

Level of content:
Basic | Intermediate
Construction & Testing

André Desjarlais

OakRidge National Laboratory

André Desjarlais is the Group Leader for the Building Envelopes Research Program at the Oak Ridge National Laboratory. He has been involved in building envelope and materials research for 40 years, first as a consultant and, for the last 22 years, at ORNL. He is active in the building industry, participating in ASHRAE, ASTM, Cool Roof Rating Council, SPRI, RCI Foundation, Roof Industry Committee on Weather Issues, Federal Roofing Committee, and the Building Environment and Thermal Envelope Council. Areas of expertise include building envelope and material energy efficiency, moisture control, and durability.

Som Shrestha, PhD, BEMP

R&D Staff
Oak Ridge National Laboratory (ORNL)

Dr. Som Shrestha is an R&D staff member within the Building Technologies Research and Integration Center at Oak Ridge National Laboratory. His current research is focused on the experimental and analytical study of the energy performance of building envelope, equipment, and systems. He is leading the development of an online energy savings calculator for building envelope airtightness. Dr. Shrestha is an ASHRAE certified Building Energy Modeling Professional (BEMP).