Skip to main content
SpringerLink
Log in

Localized air-conditioning with upper-room UVGI to reduce airborne bacteria cross-infection

  • Research Article
  • Indoor/Outdoor Airflow and Air Quality
  • Published:
Building Simulation Aims and scope Submit manuscript

Abstract

Localized airflow can result in both temperature and pollutant concentration segregations with limited mixing between adjacent environmental zones. However, when the bacteria source is within the environmental zone, it becomes important to look for effective methods to disinfect the localized air and prevent cross-infection among occupants in the same zone. This work investigates the effectiveness of upper-room ultraviolet germicidal irradiation (UVGI) in reducing airborne bacteria transmission within a zone conditioned by localized ceiling-mounted airconditioning system that recirculates return air. A computational fluid dynamics (CFD) model was developed to simulate the transport and inactivation by UV of Serratia marcescens, an extremely UV-susceptible microorganism. The CFD–UV model was validated using measurements of airflow, temperature, and UV irradiance. Numerous CFD simulations were performed for a case study to determine the maximal fraction of return air that can be recirculated for energy conservation without violating the indoor air quality standards for CO2 and bacteria concentrations. Results revealed that a maximum of 23% return air can be tolerated when minimal UV output of 15 W is delivered to the space. The use of the optimal setting reduced the energy consumption of the system by 15% compared to 100% fresh air case without UVGI.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • American Conference of Governmental Industrial Hygienists (2012). 2012 TLVs and BEIs. Cincinnati: ACGIH Signature Publications.

    Google Scholar 

  • ANSYS (2012). ANSYS Fluent 14.5.

    Google Scholar 

  • Ariff M, Salim MS, Cheah SC (2009). Wall y+ approach for dealing with turbulent flow over surface mounted cube: Part2—High Reynolds number. In: Proceedings of 7th International Conference on CFD in the Minerals and Process Industries CSIRO, Melbourne, Australia.

    Google Scholar 

  • ASHRAE (2004). ANSI/ASHRAE Standard 55-2004, Thermal Environmental Conditions for Human Occupancy. Atlanta: American Society of Heating, Refrigeration and Air-Conditioning Engineers.

    Google Scholar 

  • ASHRAE (2007a). ANSI/ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality. Atlanta: American Society of Heating, Refrigerating and Air-conditioning Engineers.

    Google Scholar 

  • ASHRAE (2007b). ASHRAE Standard 52.2-2007, Method of Testing General Ventilation Air-cleaning Devices for Removal Efficiency by Particle Size. Atlanta: American Society of Heating, Refrigerating and Air-conditioning Engineers.

    Google Scholar 

  • Beggs CB, Kerr JG, Donnelly JK, Sleigh PA, Mara DD, Cairns G (2000). The resurgence of tuberculosis in the tropics. An engineering approach to the control of Mycobacterium tuberculosis and other airborne pathogens: A UK hospital based pilot study. Transactions of the Royal Society of Tropical Medicine and Hygiene, 94: 141–146.

    Google Scholar 

  • Chen Q, Srebric J (2000). Simplified diffuser boundary conditions for numerical room airflow models. Final Report for ASHRAE RP- 1009, Massachusetts Institute of Technology, USA.

    Google Scholar 

  • Chmielewski M, Gieras M (2013). Three-zonal wall function for k–e turbulence models. Computational Methods in Science and Technology (CMST), 19: 107–114.

    Google Scholar 

  • Fennelly KP, Martyny JW, Fulton KE, Orme IM, Cave DM, Heifets LB (2004). Cough-generated aerosols of Mycobacterium tuberculosis. A new method to study infectiousness. American Journal of Respiratory and Critical Care Medicine, 169: 604–609.

    Google Scholar 

  • First M, Rudnick SN, Banahan KF, Vincent RL, Brickner PW (2007). Fundamental factors affecting upper-room ultraviolet germicidal irradiation—Part I. Experimental. Journal of Occupational and Environmental Hygiene, 4: 321–331.

    Google Scholar 

  • Gao NP, Niu JL (2007). Modeling particle dispersion and deposition in indoor environments. Atmospheric Environment, 41: 3862–3876.

    Google Scholar 

  • Gupta JK, Lin CH, Chen Q (2010). Characterizing exhaled airflow from breathing and talking. Indoor Air, 20: 31–39.

    Google Scholar 

  • Gilkeson CA, Noakes C (2013). Application of CFD simulation to predicting upper-room UVGI effectiveness. Photochemistry and Photobiology, 89: 799–810.

    Google Scholar 

  • Hathway EA, Noakes CJ, Sleigh PA, Fletcher LA (2011). CFD simulation of airborne pathogen transport due to human activities. Building and Environment, 46: 2500–2511.

    Google Scholar 

  • Joubert A, Laborde JC, Bouilloux L, Chazelet S, Thomas D (2011). Modelling the pressure drop across HEPA filters during cake filtration in the presence of humidity. Chemical Engineering Journal, 166: 616–623.

    Google Scholar 

  • Kanaan M, Ghaddar N, Ghali K, Araj G (2014). New airborne pathogen transport model for upper-room UVGI spaces conditioned by chilled ceiling and mixed displacement ventilation: Enhancing air quality and energy performance. Energy Conversion and Management, 85: 50–61.

    Google Scholar 

  • Ko G, First MW, Burge HA (2000). Influence of relative humidity on particle size and UV sensitivity of Serratia marcescens and Mycobacterium bovis BCG aerosol. Tubercle and Lung Disease, 80: 217–228.

    Google Scholar 

  • Kujundzic E, Hernandez M, Miller SL (2007). Ultraviolet germicidal irradiation inactivation of airborne fungal spores and bacteria in upper-room air and HVAC in-duct configurations. Journal of Environmental Engineering and Science, 6: 1–9.

    Google Scholar 

  • Lai ACK, Nazaroff WW (2000). Modeling indoor particle deposition from turbulent flow onto smooth surfaces. Journal of Aerosol Science, 31: 463–476.

    Google Scholar 

  • Lai KM, Burge HA, First MW (2004). Size and ultraviolet germicidal irradiation susceptibility of Serratia marcescens when aerosolized from different suspending media. Applied and Environmental Microbiology, 70: 2021–2027.

    Google Scholar 

  • Li Y, Zhao B (2012). Application of building simulation tools for studying airborne infection and its control. Building Simulation, 5: 3–4.

    Google Scholar 

  • Lindsley WG, King WP, Thewlis RE, Reynolds JS, Panday K, Cao G, Szalajda JV (2012). Dispersion and exposure to a cough-generated aerosol in a simulated medical examination room. Journal of Occupational and Environmental Hygiene, 9: 681–690.

    Google Scholar 

  • Lo LJ, Novoselac A (2010). Localized air-conditioning with occupancy control in an open office. Energy and Buildings, 42: 1120–1128.

    Google Scholar 

  • Makhoul A, Ghali K, Ghaddar N, Chakroun W (2013). Investigation of particle transport in offices equipped with ceiling-mounted personalized ventilators. Building and Environment, 63: 97–107.

    Google Scholar 

  • Memarzadeh F, Xu W (2012). Role of air changes per hour (ACH) in possible transmission of airborne infections. Building Simulation, 5: 15–28.

    Google Scholar 

  • Miller FJ, Gardner DE, Graham JA, Lee Jr RE, Wilson WE, Bachmann JD (1979). Size considerations for establishing a standard for inhalable particles. Journal of the Air Pollution Control Association, 29: 610–615.

    Google Scholar 

  • Morawska L (2006). Droplet fate in indoor environments, or can we prevent the spread of infection? Indoor Air, 16: 335–347.

    Google Scholar 

  • Nicas M, Nazaroff W, Hubbard A (2005). Toward understanding the risk of secondary airborne infection: Emission of respirable pathogens. Journal of Occupational and Environmental Hygiene, 2: 143–154.

    Google Scholar 

  • Noakes C, Beggs C, Sleigh P (2004). Modelling the performance of upper room ultraviolet germicidal irradiation devices in ventilated rooms: Comparison of analytical and CFD methods. Indoor and Built Environment, 13: 477–488.

    Google Scholar 

  • Oh MS, Ahn JH, Kim DW, Jang DS, Kim Y (2014). Thermal comfort and energy saving in a vehicle compartment using a localized air-conditioning system. Applied Energy, 133: 14–21.

    Google Scholar 

  • Papineni RS, Rosenthal FS (1997). The size distribution of droplets in the exhaled breath of healthy human subjects. Journal of Aerosol Medicine: Deposition, Clearance, and Effects in the Lung, 10: 105–116.

    Google Scholar 

  • Patankar SV (1980). Numerical Heat Transfer and Fluid Flow. Washington DC: Hemisphere.

    MATH  Google Scholar 

  • Rahn RO, Xu P, Miller SL (1999). Dosimetry of room-air germicidal irradiation using spherical actinometry. Photochemistry and Photobiology, 70: 314–318.

    Google Scholar 

  • Rudnick SN, First MW (2007). Fundamental factors affecting upper-room ultraviolet germicidal irradiation—Part II. Predicting effectiveness. Journal of Occupational and Environmental Hygiene, 4: 352–362.

    Google Scholar 

  • Schmidt MG, Attaway HH, Terzieva S, Marshall A, Steed LL, Salzberg D, Hamoodi HA, Khan JA, Feigley CE, Michels HT (2012). Characterization and control of the microbial community affiliated with copper or aluminum heat exchangers of HVAC systems. Current Microbiology, 64: 141–149.

    Google Scholar 

  • Speziale CG (1987). On nonlinear k–l and models of turbulence. Journal of Fluid Mechanics, 178: 459–475.

    MATH  Google Scholar 

  • Srebric J, Chen Q (2001). A method of test to obtain diffuser data for CFD modeling of room airflow. ASHRAE Transactions, 107(2): 108–116.

    Google Scholar 

  • Singh P, Mahajan RP, Murty GE, Aitkenhead AR (1995). Relationship of peak flow rate and peak velocity time during voluntary coughing. British Journal of Anesthesia, 74: 714–716.

    Google Scholar 

  • Sung M, Kato S (2010). Method to evaluate UV dose of upper-room UVGI system using the concept of ventilation efficiency. Building and Environment, 45: 1626–1631.

    Google Scholar 

  • Van Sciver M, Miller S, Hertzberg J (2011). Particle image velocimetry of human cough. Aerosol Science and Technology, 45: 415–422.

    Google Scholar 

  • Wainwright CE, France MW, O’Rourke P, Anuj S, Kidd TJ, Nissen MD, Sloots TP, Coulter C, Ristovski Z, Hargreaves M, Rose BR, Harbour C, Bell SC, Fennelly KP (2009). Cough-generated aerosols of Pseudomonas aeruginosa and other Gram-negative bacteria from patients with cystic fibrosis. Thorax, 64: 926–931.

    Google Scholar 

  • Wan M, Chao C (2005). Numerical and experimental study of velocity and temperature characteristics in a ventilated enclosure with under floor ventilation systems. Indoor Air, 15: 342–355.

    Google Scholar 

  • Wells WF (1934). On air-borne infection. Study II. Droplets and droplet nuclei. American Journal of Hygiene, 20: 611–618.

    Google Scholar 

  • WHO (1988). Indoor air quality: Biological contaminants. World Health Organization, European Series, n. 31, Copenhagen, Denmark.

    Google Scholar 

  • Wu CL, Yang Y, Wong SL, Lai ACK (2011). A new mathematical model for irradiance field prediction of upper-room ultraviolet germicidal systems. Journal of Hazardous Materials, 189: 173–185.

    Google Scholar 

  • Xu PJ, Peccia J, Fabian P, Martyny JW, Fennelly KP, Hernandez M, Miller SL (2003). Efficacy of ultraviolet germicidal irradiation of upper-room air in inactivating airborne bacterial spores and mycobacteria in full-scale studies. Atmospheric Environment, 37: 405–419.

    Google Scholar 

  • Xu Z, Shen F, Li X, Wu Y, Chen Q, Jie X, Yao M (2012). Molecular and microscopic analysis of bacteria and viruses in exhaled breath collected using a simple impaction and condensing method. PLoS ONE, 7: e41137.

    Google Scholar 

  • Zhang Z, Chen Q (2007). Comparison of the Eulerian and Lagrangian methods for predicting particle transport in enclosed spaces. Atmospheric Environment, 41: 5236–5248.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Mechanical Engineering, American University of Beirut, Bliss Street, 1107 2020, Beirut, Lebanon

    Mohamad Kanaan, Nesreene Ghaddar & Kamel Ghali

Authors
  1. Mohamad Kanaan
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Nesreene Ghaddar
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Kamel Ghali
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Nesreene Ghaddar.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Kanaan, M., Ghaddar, N. & Ghali, K. Localized air-conditioning with upper-room UVGI to reduce airborne bacteria cross-infection. Build. Simul. 9, 63–74 (2016). https://doi.org/10.1007/s12273-015-0250-7

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12273-015-0250-7

Keywords

Search

Navigation