Estimating the effects of ambient conditions on the performance of UVGI air cleaners

Lau, Josephine; Bahnfleth, William P.; Freihaut, James D.

doi:10.1016/j.buildenv.2008.05.015

Cited by 25 publications

(25 citation statements)

References 3 publications

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“…A similar trend has been reported in the literature. 17,21 Previous study has observed there is an optimal operation surface temperature for achieving maximum UV output from low-pressure mercury lamps. 21 The irradiation output was affected by the mercury vapor pressure which was influenced by the cold-spot temperature.…”

Section: Data Reductionmentioning

confidence: 99%

“…21 The irradiation output was affected by the mercury vapor pressure which was influenced by the cold-spot temperature. 17 From the perspective of heat transfer, this cold-spot surface temperature can be affected by the ambient airflow and temperature. This observation was confirmed by measuring the air temperature and coldest surface temperature of the lamp simultaneously, as shown in Figure S3 of the supporting information.…”

Section: Data Reductionmentioning

confidence: 99%

“…10 The irradiance depends on the power rating of the UV source and on environmental factors. 17 Previous experimental studies of in-duct UV lamps in a turbulent flow in a full-scale duct examined only one environmental duct airflow condition. 8,9 This limited information is not practically useful for engineers designing new systems due to the varied air parameters in practical HVAC systems.…”

mentioning

confidence: 99%

“…21 The ambient airflow velocity and temperature affect the UV lamp surface temperature and radiation output by influencing the mercury vapor pressure in the lamp. 17,22 The mercury vapor pressure can be decreased using amalgams instead of pure mercury. 21 Measurement of the UV lamp output as a function of the lamp surface (cold spot) temperature revealed that the lamp output first increased with the surface temperature and then decreased.…”

mentioning

confidence: 99%

“…24 Although a few studies have measured the effect of surface temperature on the output of UV lamps, none have simultaneously measured the disinfection efficacy of UV lamps on airborne bacteria. 17,23,25 Many UV lamp manufacturers provide no information about UV performance, and even those that do tend to provide information for only one air condition. This can cause serious problems when a device is used in different environmental conditions.…”

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confidence: 99%

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Disinfection by in‐duct ultraviolet lamps under different environmental conditions in turbulent airflows

et al. 2020

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In this study, we investigated the effects of environmental factors such as airflow velocity, relative humidity (RH), temperature, and duct reflectance on the performance of in‐duct UVC lamps. Staphylococcus epidermidis, Pseudomonas alcaligenes, and Escherichia coli were used as the test bacteria. The UV irradiance, disinfection efficacy, and UV susceptibility constant (Z value) of the test bacteria were experimentally determined. The results showed that the UV disinfection efficacy decreased as the airflow velocity and RH increased. The maximum UV disinfection efficacy was obtained at temperature of 20‐21°C compared with the performance at lower temperature (15‐16°C) and higher temperature (25‐26°C). When the RH increased from 50% to 90%, the Z values of airborne bacteria reduced by 40%, 60%, and 38% for S epidermidis, P alcaligenes, and E coli, respectively. Besides, susceptibility constants had lower values under both cooling temperature (15‐16°C) and heating temperature (25‐26°C) compared with that under the temperature of 20‐21°C. It was observed that S epidermidis generally had the highest resistance to the UV irradiance. The results also showed that the UV disinfection efficacy was lower in the duct with a black surface than in the clean duct.

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Section: Data Reductionmentioning

confidence: 99%

Section: Data Reductionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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