Enhancing Air Quality for Embedded Hospital Germicidal Lamps

Abstract

The indoor air of a hospital is always full of bacteria and viruses due to patients with different diseases. These bacteria and viruses could be highly infectious to the people in the hospital irrespective of their health conditions, and could be hazardous to the patients, their care takers, and hospital staff. Thus, keeping a good hospital air quality is very essential to the operation of the hospital. This study aims at enhancing ventilation of the interior lighting of hospitals with germicidal capabilities. Air disinfection is accomplished by adding the specially designed disinfecting filters and fans to existing embedded lamps in the hospitals. The embedded lamp has a square shape of 601 mm in width and 112 mm in thickness. In the design stage, the air flow inside the embedded lamp with the added filters and fans was investigated by numerical simulation using a computational fluid dynamics (CFD) tool. Three designs, referred to as Types 1, 2, and 3, were evaluated using steady-state CFD flow simulations. The ventilation rate of the Type 1 design was about 251.9 CMH, and 348.3 CMH for the Type 2 design by increasing the fan outlet area. However, even though the ventilation was increased by 34%, the flow field of the Type 2 design was not uniform, resulting in flows being circulated around the side locations. Thus, the Type 3 design further treats this aspect by streamlining the outlet geometry and adding flow guiding vanes to reduce flow resistance and flow unsteadiness; the corresponding air ventilation rate reached 376.3 CMH. Hence, the Type 3 design was fabricated and tested. The test results confirm that the design not only has a higher ventilation rate but also operates under a smaller pressure drop, thus accomplishing the goal of providing good air quality in the hospital environment efficiently. Moreover, the associated flow noise is reduced by about 8 dBA. Hence, both an increase in the air ventilation rate and a reduction of noise are achieved simultaneously by the present method.

Current approaches for preventing environment-associated contamination in healthcare facilities: a systematic literature review by open access database

“…In this way, they investigate the effectiveness of conditioned air released from air conditioning machines to mix the aerosol sanitiser to reach every corner of the AII room and kill the SARS-CoV-2 [ 38 ]. Chen et al (2021) [ 40 ] combined fans with germicidal filters and installed them in hospital lighting to improve the air quality of hospitals. The researchers examined the performance of three embedded hospital germicidal lamp module designs, with air filters and various fan configurations [ 40 ].…”

“…Chen et al (2021) [ 40 ] combined fans with germicidal filters and installed them in hospital lighting to improve the air quality of hospitals. The researchers examined the performance of three embedded hospital germicidal lamp module designs, with air filters and various fan configurations [ 40 ]. Based on that, the module that performed better was implemented and tested.…”

“…Based on that, the module that performed better was implemented and tested. The results showed that both air quality and fan energy-saving can be achieved economically and simultaneously [ 40 ].…”

“…As an example, there is a chamber to isolate the patient to be tested. After the examination, all surfaces of the chamber were sprayed with disinfectant [ 44 ] Importance of knowing the different products for cleaning surfaces in hospital environments, since excessive and inefficient use of disinfectants may increase the hospital’s risk of becoming an incubator for resistant pathogens [ 43 ] Importance of developing and testing new products, such as long-acting disinfectants for persistent disinfection (similar to the effect of copper surfaces) [ 38 , 40 ] Need to develop systems that allow the disinfection of the hospital environment in a more complete way, in order to reach all surfaces and corners, such as aerosolized sanitisation system. Another system developed combines fans with germicidal filters that were installed in hospital lighting to improve the air quality of hospitals [ 39 ] Need to think about mitigation measures for COVID-19 beyond those depending on human behaviour (minimise time exposed to the virus, social distancing, and wear personal protection equipment).…”

Disinfection performance of an ultraviolet lamp: a CFD investigation

“…The worldwide outbreak of Coronavirus (COVID- 19), which terribly affects human health and the world economy, has drawn a great awareness of infectious diseases' danger. Numerous intensive studies have been carried out to improve the disinfection efficiency in hospitals where many patients with serious underlying medical conditions stay [1][2][3][4][5]. In order to prevent the virus spread, various controlling techniques, such as air filtration, heat sterilization, chemical disinfectants, and Ultraviolet Germicidal Irradiation (UVGI), have been employed [6].…”