Assistant Professor
Department of Civil, Architectural, and Environmental Engineering
University of Texas at Austin
Active Projects:
CFD Resource Decision in Particle Transport Modeling
Supported by ASHRAE
The project outcome should provide the engineering and research community with critical CFD parameters suitable for particle transport modeling in a built environment where disease-bearing particles can cause human exposure and health risks. The specific project objectives are: 1) compare RANS-Lagrangian and LES-Lagrangian particle modeling methods for representative indoor airflows, 2) analyze the trade-offs between accuracy and computational expense for the two methods and identify scenarios where more affordable RANS-Lagrangian method provides satisfactory accuracy, and 3) define critical parameters for RANS-Lagrangian particle modeling method considering the characteristics of disease-bearing particle transport in indoor environments.
Inhalation Exposure to Pollutants in the Sleeping Microenvironment
Supported by NSF-IGERT
Adults spend an average of 7.5 hours in bed per night, which corresponds to approximately one-third of our life. Previous research has found that we are exposed to numerous pollutants while sleeping, notably airborne allergen-containing particles, such as dust mite fecal matter and particles carrying pet allergens, and gaseous pollutants such as volatile organic compounds and flame retardants. The objective of this research is to characterize the sources of particulate and gaseous pollutants in the sleeping microenvironment and investigate how the airflow around the human body while sleeping transports pollutants from bedding materials to a person’s breathing zone. By understanding how we are exposed to pollutants while sleeping, it will enable us to make recommendations and propose control strategies to reduce our exposure, such as using portable air cleaners and proposing ventilation requirements for bedrooms.
A student working on this project is Brandon Boor, and he is currently working on the source characterization by studying resuspension of particles from indoor surfaces.
Fluctuating Wind Pressure Boundary Conditions for Ventilation Modeling
Supported by NSF-IGERT
Methodology that enables calculation of a rate at which air enters and exits a building at various ventilation openings of a naturally ventilated building is critical to the building design and many air quality analyses. To capture the effects that wind has on overall airflow rate and pollutant transport in naturally ventilated buildings, it is necessary to integrate wind unsteadiness into analytical and numerical models for natural ventilation studies. This research investigates the accuracy and sensitivity of the computational fluid dynamics (CFD) modeling methods considering the critical modeling parameters such as frequency of wind pressure oscillation, geometry of openings, and time step and computation grid resolution. The project should provide guidance on the appropriate use of CFD modeling for natural ventilation as well as assessment of natural ventilation impact on human exposure to indoor and outdoor airborne pollutants. The study will provide data useful to researchers studying pollutant transport between indoor and outdoor environment and design tool for engineers and architects involved in design of buildings and ventilation systems. A student involved in this project is James Lo and he is supported form UT Indoor Environmental Science IGERT Program.
Development of Internal Surface Convection Correlations for Energy and Load Calculation Methods
Supported by ASHRAE
Convection correlations for building surfaces are important components of building design and energy simulation models since the heat exchange between the indoor and outdoor environment depends on surface convection together with conduction and radiation. The main objective of this study is to provide engineering and research community with critical building, heating, ventilation, and air-conditioning design parameters in the form of improved convection coefficients. The project outcomes are correlations for convective heat transfer at external walls in rooms with ceiling slot diffusers and floor supply registers, suitable for thermal load calculation and building energy efficiency analyses.
Design Procedure for Stack Pressure Control in High Rise Residential Buildings
Supported by GS Construction Co.
The goal of this project is to advance existing and develop new methods for energy efficient control of stack pressure and infiltration rate in high rise residential buildings. This includes improvements in: building envelope, zone distribution, ventilation and filtration systems, as well as analysis of smoke distribution a case of fire. The research work also includes development of energy efficient control of gaseous particle pollutants in high rise residential buildings.
Integration of Phase Change Materials in Building Structure and Furnishing
Supported by various donors and research awards
Thermal storage systems are crucial for a building system that saves energy by moving thermal energy (heating or cooling) from a period when it is abundant to the period when it is deficient. Also, these systems help to cut the peak power consumption for building cooling and shift the cooling load from the daily period when the efficiency of cooling system is low (high air temperature during the day) to the period when the efficiency is high (lower air temperature during the night). This project explores suitable phase change materials and evaluates different options for the integration of phase change materials in the building structure (floor, fa?de, interior walls, and furnishing) in combination with characterization of their performance.
Green Building, Sustainability, and Energy Efficiency in the UTest House
Supported by Faculty Innovation grant, UT, PI: Jeffery Siegel
In this project the simultaneous development of a structured laboratory experience at the UTest House and a virtual interface to display measurements from the house in real time. Students will be able to visit the test house in the context of field trips or laboratory and see the systems and the house and, where appropriate, make measurements. Students will be able to log into an online user interface to collect data in real time from planned or natural experiments. Also models (BIM) of the UTest House will also be integrated into the data tool.
Finished Projects:
Heat Transfer Modeling on Window Surfaces
Supported by ASHRAE Grant-in-aid
The accurate modeling of glazed facades is crucial to load calculations and energy analyses, and the objectives of the proposed research are to extend the ongoing research related to convection correlation development for internal surfaces, currently funded by ASHRAE, and generate results for the development of models that take into account the influence of shading devices on radiative and convective heat transfer in commercial buildings with ceiling slot diffusers.
Airflow with Localized Air-Conditioning in Open Offices
Supported by ASHRAE Grant-in-aid
Distributed heating, ventilation and air-conditioning (HVAC) systems with occupancy control are characterized by their ability to create independently controlled environmental zones. This generates potential for energy saving when these systems are applied in open offices which are only partially occupied. To evaluate these systems the study tests if the independent control of zone in an open space is possible and what are the energy benefits.
Occupational Exposure to Hazardous Airborne Pollutants: Effect of Source Characteristics
Supported by NIOSH (SWCOEH), ASHRAE Grant-in-aid, and several other research awards
The source characteristics, ventilation strategy, and occupant breathing and activity have a measurable influence on the pollutant concentration in the occupant’s breathing zone, and accordingly, the occupant exposure. The goal of this research is to provide a unique set of data that show 1) How do gaseous pollutants and particulate matters behave around the human body with respect to the overall space airflow (2) how does the movement of an occupant affect the airflow and pollutant transport in the vicinity of the occupant, and (3) which parameter can be used as an easily detectable air quality indicator for occupant exposure to both gaseous pollutant and particulate matter. A UT graduate, Dr. Donghyun Rim, has been working on this experimental and modeling based project, and more information about the use of Computational Fluid Dynamics (CFD) simulations in human exposure analyses is available on his website.
Supported by Die Tile Co.
The project provides systematic study that shows how floor properties affect the building thermal performance. The study analyzes the benefits that increased thermal mass of flooring systems has on annual energy consumption and examines how different thermal properties, dimension, and installation of floor finishing materials affect the building thermal performance.
Transport and Fate of Ambient Ultrafine Particles in Buildings
Supported by NIST
When particle-laden outdoor air infiltrates through the building envelope, some of the particles deposit onto the surfaces of cracks and the remaining particles penetrate into the indoor environment. The main objectives of the proposed research are to: (1) study the penetration and deposition of ultrafine particles from 2 to 50 nm in real buildings and (2) investigate ultrafine particle generation and collection methods for studies of particle dynamics and physical and chemical properties. The study uses experimental measurements combined with analytical modeling to study the transport and fate of ambient particles ranging from 2 to 50 nm.
Integration of Photovoltaic Systems in High-rise Buildings
Supported by Samsung Construction Co.
The objective of this project is to evaluate the benefits of applying Photovoltaic (PV) systems in high-rise buildings. The study includes analysis of residential and commercial buildings with and without double-skin facade. The research is based on energy and airflow simulations and the results provide anticipated reduction in building energy consumption following the installation of various PV systems. The research results will help to develop design methodologies for achieving targeted reduction of overall building energy consumption in various commercial and residential buildings.
Supported by ASHRAE, PI: Jeffery Siegel
The goal of this project is to determine the energy consequences of different levels of filtration on residential and light commercial construction. This energy and filter project involves periodic measurements of fan and system energy use in eight residential and nine light commercial buildings during different seasons and with different levels of filtration. Additional continuous measurements have been conducted in the UT test house at the Pickle Research Center in order to vary all of the relevant parameters. The measurement data has been collected into an empirical model that relates filtration to energy consequences. Dr Novoselac was involved in data acquisition design, student training and monitoring, and measurements quality control.
Supported by DOE and various sponsors, PI: Michael Garrison
The Solar Decathlon is the project that includes research, design, testing and construction of a prototype of solar powered residential house. The UT project was 2-years long and the final event takes place in October 2007 at the National Mall in Washington, D.C. The qualified teams were partially sponsored by the Department of Energy (DOE) and donations from industry in money and equipment. At the final event of this project, Solar Decathlon Competition at Washington DC., Dr. Novoselac’s engineering team won the second prize for the engineering design analysis.
Building Information Models as a Teaching Tool
Supported by UT’s Faculty Innovation grant, PI: William O'Brien
The goal of this project was to develop a 3D cad model convert it into BIM tool and use this model to teach architectural engineering students to use BIM for project management and design of optimal ventilation duct systems.