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Presenter Bio: Daniel Rush

Daniel Rush University of Texas at Austin 10500 Exploration Way Austin, TX 78758 United States (702) 846-8912 Dan Rush is a Ph.D. Candidate in the Building Energy and Environments program, Department of Civil, Architectural, and Environmental Engineering, at the University of Texas at Austin. He earned his B.S. in Mechanical/Aerospace Engineering and commission in the U.S. Air Force at Oklahoma State University in 1988. He completed Navigator and Electronic Warfare Officer training at Mather AFB, CA, in 1989 and flew worldwide operational reconnaissance missions as an RC-135 instructor and mission commander in combat, combat support, and sensitive operations from 1990 through 1999. He completed his M.S. in Manufacturing Systems Engineering at the University of Nebraska-Lincoln in 1998 and graduated from the USAF Test Pilot School in 2000 as an Experimental Flight Test Navigator. He served the remainder of his Air Force career in flight test, except for a seven-month deployment to southwest Asia in a diplomatic role. He retired from the Air Force in 2008, and then worked as a defense contractor flight test engineer for 12 years. He retired again in 2020, though he still consults part-time on flight test design. Not being very good at retiring, and still harboring a lifelong interest in energy efficient building design, he began the Ph.D. program at the University of Texas at Austin in fall 2020, and along the way completed his M.S.E. in Civil Engineering in December 2021. His interests include building energy efficiency and indoor environmental quality, and his research involves ceiling fans to aid in both thermal comfort and indoor air quality. Memberships: Indoor Air Quality Association (IAQA), American Association for Aerosol Research (AAAR), American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE), American Society of Civil Engineers (ASCE), Architectural Engineering Institute (AEI), American Institute of Aeronautics and Astronautics (AIAA), Society of Flight Test Engineers (SFTE), Veterans of Foreign Wars (VFW), Student Veterans Association (SVA) Conference Presentations: Kumar, S., Tang, M., Rush, D., Zhu, N., and Novoselac, A. (2022, June 15). Investigating Mixing and Dispersion Mechanisms of Gaseous Pollutants and Particles in Residences [Conference Presentation]. Indoor Air 2022, Kupio, Finland. Tang, M., Rush, D., Kumar, S., and Novoselac, A. (2022, October 3-7). Mixing and Dispersion of Aerosols in Multi-Zone Residences [Conference Presentation]. American Association for Aerosol Research 40th Annual Conference, Raleigh, NC, United States. Rush, D., Tang, M., Kumar, S., and Novoselac, A. (2023, February 19-22). Ceiling Fans for Pollutant Mixing and Dispersion in Multi-Zone Residences [Conference Presentation]. Indoor Air Quality Association 2023 Annual Meeting and Expo, Austin, TX, United States.

Presentation Description:

Ceiling Fans for Pollutant Mixing and Dispersion in Multi-Zone Residences

Daniel Rush1,*, Mengjia Tang1, Sangeetha Kumar1, Atila Novoselac1

1 The University of Texas at Austin, Austin, TX, USA

*Corresponding email:  

Gaseous and particulate pollutants may be released in a home due to cooking, cleaning, walking, talking, and other actions by humans or pets. Just a few of the many other sources include microbial metabolic processes, personal care products, and building material emissions. High pollutant concentration exposure may cause discomfort or adverse health effects. The primary defense against indoor air pollutants is to eliminate or reduce emissions. The secondary defense is targeted ventilation or filtration at the source, as with a range hood over the stove, or a portable air cleaner. Still, some of the targeted pollutants may escape even a high-flow-rate range hood, and emission events sometimes occur at locations where targeted ventilation is not available. The third defense is to mix the house air as quickly as possible to eliminate the proximity effect of individual exposure to localized high concentrations, and then to reduce the well-mixed concentration gradually with whole-house ventilation, exfiltration, or filtration. The mixing component of that third step is the focus of this study. Continuous HVAC fan operation for mixing uses more energy than normal intermittent operation only as needed for heating or cooling. As an alternative to the HVAC fan, ceiling fans can be used for mixing. Ceiling fans generate large volumetric flow rates using low power, so they might achieve an equal or better mixing rate than continuous HVAC fan operation while consuming less energy. The objective of this study is to compare the effectiveness and energy consumption of continuous operation of the HVAC fan and ceiling fans in mixing gaseous and particulate pollutants in a multi-zone residence. Controlled experiments were conducted in the University of Texas at Austin Test House, a three-bedroom, two-bath home equipped with an HVAC system and four ceiling fans: one in the main living area and one in each of the bedrooms. Concentrations of tracer gas (CO2) and coarse (2.5-10 μm), fine (0.3-2.5 μm), and ultrafine (<0.1 μm) particulate matter (PM) were measured in multiple rooms during and after tracer gas and PM injection events in the kitchen. The injection event durations varied to mimic instantaneous (less than 1 minute), short-term (15 minutes), and long-term (2 hours) cooking. Each of the three injection events were conducted using three mixing methods: with all fans off, with only the HVAC fan running, and with only the ceiling fans running. Whole house electric power was also measured for each mixing method. Preliminary results indicate that ceiling fans can be as effective as continuous HVAC fan operation for the mixing component of indoor air quality improvement using less energy.