Comparing airborne infectious aerosol exposures in sparsely occupied large spaces utilizing large-diameter ceiling fans

Senwen Yang, Liangzhu (Leon) Wang*, Paul Raftery, Michael Ivanovich, Christian Taber, William P. Bahnfleth, Pawel Wargocki, Jovan Pantelic, Jiwei Zou, Mohammad Mortezazadeh, Chang Shu, Runzhong Wang, Scott Arnold

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

In sparsely occupied large industrial and commercial buildings, large-diameter ceiling fans (LDCFs) are commonly utilized for comfort cooling and destratification; however, a limited number of studies were conducted to guide the operation of these devices during the COVID-19 pandemic. This study conducted 223 parametrical computational-fluid-dynamics (CFD) simulations of LDCFs in the U.S. Department of Energy warehouse reference building to compare the impacts of fan operations, index-person, and worker-packing-line locations on airborne exposures to infectious aerosols under both summer and winter conditions. The steady-state airflow fields were modeled while transient exposures to particles of varying sizes (0.5–10 μm) were evaluated over an eight-hour period. Both the airflow and aerosol models were validated by measurement data from the literature. It was found that it is preferable to create a breeze from LDCFs for increased airborne dilution into a sparsely occupied large warehouse, which is more similar to an outdoor scenario than a typical indoor scenario. Operation of fans at the highest feasible speed while maintaining thermal-comfort requirements consistently outperformed the other options in terms of airborne exposures. There is no substantial evidence that fan reversal is beneficial in the current large space of interest. Reversal flow direction to create upward flows at higher fan speeds generally reduced performance compared with downward flows, as there was less airflow through the fan blades at the same rotational speed. Reversing flow at lower fan speeds decreased airflow speeds and dilution in the space and, thus, increased whole-warehouse concentrations.
Original languageEnglish
Article number110022
JournalBuilding and Environment
Volume231
Number of pages17
ISSN0360-1323
DOIs
Publication statusPublished - 2023

Bibliographical note

This project was funded by Air Movement and Control Association (AMCA) International. The authors acknowledge the valuable input and/or support of Dr. Geoffrey Sheard of AGS Consulting, Eddie Boyd of Macroair, Marc Brandt of Hunter Industrial, Thomas Catania of the Institute for Energy Innovation, Mark Stevens of AMCA International, and Mike Wolf of Geenheck Fan. Special thanks to Dr. Naiping Gao of Tongji University, China, and Dr. Bin Zhao of Tsinghua University, China, for sharing their team's work on the ANSYS FLUENT UDFs. The project was made possible by the Concordia University High-Performance Computing cluster SPEED.

Keywords

  • COVID-19
  • SARS-CoV-2
  • Airborne
  • Ceiling fan
  • Warehouse
  • CFD
  • Drift-flux

Fingerprint

Dive into the research topics of 'Comparing airborne infectious aerosol exposures in sparsely occupied large spaces utilizing large-diameter ceiling fans'. Together they form a unique fingerprint.

Cite this