{"title":"Effects of Distance, Temperature, and Relative Humidity on the Irradiance of Ultraviolet-C Germicidal Lamp: A Quantitative Study","authors":"Yu Wu, Yuqi Wang, Jinyang Liu, Xinyang Xu, Youwen Song, Xiaorong Zhang, Lili Jiang, Peng Chen","doi":"10.1155/2024/1951792","DOIUrl":null,"url":null,"abstract":"<p>Ultraviolet germicidal irradiation (UVGI) as an engineering control against pathogenic microbes necessitates a clear understanding of operational parameters and environmental effects on inactivation rates. Here, we investigated the variation laws of ultraviolet-C (UV-C) irradiance under the influence of distance, ambient conditions of temperature, and relative humidity (RH) in a dark chamber using 30-W low-pressure mercury lamps, and all data were analyzed with curve fitting methods. UV-C irradiances in each plane were measured as the distance adjusting between 0.5 and 1.2 m, and a threshold of 70 <i>μ</i>W/cm<sup>2</sup> was utilized to calculate the effective irradiation area. For the temperature and RH, UV-C irradiances were measured at 1 m perpendicular from the lamp axis at the lamp midpoint, with the ambient temperature increasing from 15.5°C to 40°C and RH adjusting from 10% to 97%. Results showed that the UV-C irradiance and effective irradiation area exhibited a notable decrease as the distance increased, both corresponded to polynomial 2nd order fits. The UV-C lamps operate at maximum efficiency at 20°C. Temperature above or below the optimum value will decrease UV output, especially when the ambient temperature exceeds 38°C and the irradiance decreases by 16% compared to the observed maximum. However, the impact of RH on radiant power is negligible with the UV-C irradiance maintaining an overall steady state (84–91 <i>μ</i>W/cm<sup>2</sup>) in the 10%–97% RH range. The use of the measurement and modeling techniques demonstrated in this study may help understand various ambient conditions that influence the irradiance of UV-C and improve reliability and working performance of UVGI systems through better design.</p>","PeriodicalId":13529,"journal":{"name":"Indoor air","volume":"2024 1","pages":""},"PeriodicalIF":4.3000,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/1951792","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Indoor air","FirstCategoryId":"93","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1155/2024/1951792","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Ultraviolet germicidal irradiation (UVGI) as an engineering control against pathogenic microbes necessitates a clear understanding of operational parameters and environmental effects on inactivation rates. Here, we investigated the variation laws of ultraviolet-C (UV-C) irradiance under the influence of distance, ambient conditions of temperature, and relative humidity (RH) in a dark chamber using 30-W low-pressure mercury lamps, and all data were analyzed with curve fitting methods. UV-C irradiances in each plane were measured as the distance adjusting between 0.5 and 1.2 m, and a threshold of 70 μW/cm2 was utilized to calculate the effective irradiation area. For the temperature and RH, UV-C irradiances were measured at 1 m perpendicular from the lamp axis at the lamp midpoint, with the ambient temperature increasing from 15.5°C to 40°C and RH adjusting from 10% to 97%. Results showed that the UV-C irradiance and effective irradiation area exhibited a notable decrease as the distance increased, both corresponded to polynomial 2nd order fits. The UV-C lamps operate at maximum efficiency at 20°C. Temperature above or below the optimum value will decrease UV output, especially when the ambient temperature exceeds 38°C and the irradiance decreases by 16% compared to the observed maximum. However, the impact of RH on radiant power is negligible with the UV-C irradiance maintaining an overall steady state (84–91 μW/cm2) in the 10%–97% RH range. The use of the measurement and modeling techniques demonstrated in this study may help understand various ambient conditions that influence the irradiance of UV-C and improve reliability and working performance of UVGI systems through better design.
期刊介绍:
The quality of the environment within buildings is a topic of major importance for public health.
Indoor Air provides a location for reporting original research results in the broad area defined by the indoor environment of non-industrial buildings. An international journal with multidisciplinary content, Indoor Air publishes papers reflecting the broad categories of interest in this field: health effects; thermal comfort; monitoring and modelling; source characterization; ventilation and other environmental control techniques.
The research results present the basic information to allow designers, building owners, and operators to provide a healthy and comfortable environment for building occupants, as well as giving medical practitioners information on how to deal with illnesses related to the indoor environment.