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Summary
Current tools are not comprehensive when analyzing the energy use and indoor air quality (IAQ) of buildings, making it hard to analyze these factors together when making decisions about design, retrofit, or operation. We are developing tools to this type of complex analysis. We are improving our NIST-developed CONTAM software, which simulates airflow and contaminant transport in buildings, including coupling it with energy analysis tools to consider IAQ and energy impacts, and with tools used for risk-based analysis. We are integrating CONTAM with other analysis tools and developing application programming interfaces (APIs) to facilitate integration and to improve usability.
This project will help designers, researchers, and standards developers create healthier and more energy-efficient buildings. It will also support the development of industry-consensus standards and guidelines for IAQ and ventilation, ultimately improving occupant health and reducing energy consumption. The anticipated outcomes include improved building design, operation, and control, leading to better IAQ and lower energy costs.
Description
Objective
To develop and test tools to quantify and verify high-performance IAQ in high-performance buildings, and to support the development and improvement of industry-consensus building standards, guidelines, and programs related to IAQ and ventilation.
Technical Idea
The technical idea is to develop tools that analyze ventilation and indoor air quality (IAQ) within the built environment, provide input data, and facilitate the integration of these tools into relevant analysis platforms. NIST's flagship program, CONTAM, has been under continuous development for decades and has been recently advanced by coupling it with multizone, whole-building energy analysis software, such as EnergyPlus and TRNSYS. This co-simulation addresses the interdependence between building airflow and heat transfer, enabling the evaluation of energy impacts of ventilation and infiltration and IAQ impacts of low-energy building design and retrofit.
The coupled tools and associated building models have been used in various studies, including evaluating interventions to reduce energy consumption and exposure to indoor pollutants, and informing ASHRAE research and standards. NIST has also developed resources to improve infiltration modeling, including correlations based on multizone analysis of residential and non-residential building models, and an OpenStudio Measure to provide access to these correlations to support industry needs for more accurate modeling of infiltration and capturing the benefits of airtightening.
To facilitate the use of CONTAM, NIST has implemented a DevOps plan, including automating builds, implementing an automated test suite, and developing training videos. Additionally, NIST has developed application programming interfaces (APIs), ContamX and ContamW, to facilitate the integration of CONTAM into various analysis environments. The ContamX API has been incorporated into the Integrated Urban (IU) CBRN analysis environment, and Python bindings have been developed. A development version of the ContamW API has been incorporated into the Rhino/Grasshopper (RG) platform. The RG platform is widely used by architects and other building professionals so CONTAM’s integration into the platform would allow more users (and types of users) to take advantage of CONTAM’s capabilities without directly interfacing with it.
These advancements enable the analysis of IAQ and ventilation in buildings, providing a critical tool for designers, researchers, and standards developers. The products developed under this technical idea solve the measurement science problem by providing a comprehensive and integrated analysis of IAQ, ventilation, and energy use in buildings.
Research Plan
The research plan involves developing and refining software tools, supporting data, and building model templates to facilitate the design, analysis, and operation of indoor air quality (IAQ) and ventilation in high-performance buildings. The plan includes refactoring CONTAM as a dynamic link library (contamx_lib.dll) with an API (ContamX-API), enabling direct integration into various software platforms. In FY25, work began on CONTAM version 3.5, which will incorporate new features, including a 64-bit build and enhanced results file output definition, with a target release in FY26.
The plan also involves developing application programming interfaces (APIs) and bindings to facilitate integration with other software platforms. For example, the ANT plug-in was developed for the Rhino/Grasshopper platform, and a streamlined version of the CONTAM airflow solver was integrated into the QGIS platform. Additionally, the Commercial Building Airtightness Database (CBAD) will be converted to an online database and formally released in FY26.
The research plan also includes developing IAQ-related analysis methods that align with energy analysis tools. An initial demonstration will focus on the use of BEopt to generate residential building energy usage, generate associated CONTAM input files, and run simulations that align with associated BEopt cases. CONTAM simulation results will be analyzed with respect to IAQ metrics to be developed as part of the demonstration based on industry standards and guidelines. Furthermore, NIST will continue to support IAQ and ventilation-related standards development through involvement with ASHRAE and other organizations.
The products developed under this research plan will enable the analysis and optimization of IAQ and ventilation in buildings, providing a critical tool for designers, researchers, and standards developers. The plan is logically connected to the technical idea, which addresses the measurement science problem of analyzing IAQ and ventilation in buildings.
References
- Emmerich, S.J. and A.K. Persily, U.S. Commercial Building Airtightness Requirements and Measurements, in AIVC Conference 2011. 2011, AIVC: Brussels.
- Shen, J., W.S. Dols, and B.P. Polidoro, ANT: A Multizone Indoor Air Quality (IAQ) and Ventilation Analysis Plug-in for Algorithm Aided Design, in SimBuild 2024. 2024, IBPSA-USA: Denver, CO, USA.
- Emmerich, S. J., K. Y. Teichman and A. K. Persily (2017). "Literature review on field study of ventilation and indoor air quality performance verification in high-performance commercial buildings in North America." Science and Technology for the Built Environment: 1-8.
- Dols, W.S., B.J. Polidoro, D.G. Poppendieck, and S.J. Emmerich, A Tool to Model the Fate and Transport of Indoor Microbiological Aerosols (FaTIMA), TN 2095. 2020, National Institute of Standards and Technology: Gaithersburg, MD USA.
Major Accomplishments
- CONTAM version 3.5 to be released this year
- Release of CONTAM APIs
- Release of ANT
- Clearing House for Infiltration Modeling Purposes published
Impact of Industry-Consensus Standards and Tools:
- CONTAM analysis was performed to aid in developing ventilation rates for corridors of educational facilities as they pertain to ASHRAE Standard 62.1.