New airborne pathogen transport model for upper-room UVGI spaces conditioned by chilled ceiling and mixed displacement ventilation: Enhancing air quality and energy performance

The developed bacteria transport model was used in a case study to determine the return air mixing ratio that minimizes energy consumption and maintains acceptable IAQ with and without UVGI. Results showed that the use of upper-room UVGI resulted in 35% in energy saving, whereas the use of in-duct UVGI achieved no more than 12% energy saving, both compared to 100% fresh air case.