Post by Nadica (She/Her) on Jul 23, 2024 2:11:03 GMT
Assessing the portable air cleaner's effectiveness and energy efficiency in targeted removal aerosols from a negative pressure isolation ward - Published July 22, 2024
Highlights
•Evaluated air cleaner aerosol removal ability in a negative-pressure isolation ward.
•TARGETINGPAC can assess the targeting aerosol removal performance of air cleaner.
•Placement of the portable air cleaner increased the TARGETING value by 62.5 %.
•Portable air cleaner can reduce the virus load on the body surface by 85.2%–88.8 %.
•Found between 12.6% and 31.1 % reduction in energy consumption due to air cleaners.
Abstract
During the COVID-19 pandemic, negative-pressure isolation wards (NPIWs) became a crucial infrastructure for treating patients and safeguarding healthcare workers (HCWs). However, the standard requirements for full fresh air and high air changes per hour (ACH) make NPIWs extremely energy-intensive. The blind ventilation design of NPIWs also poses potential exposure risks for HCWs. To address these issues, portable air cleaners (PACs) have been proven effective in removing bioaerosols from the air, providing a clean air delivery rate (CADR) without the need for additional fresh air load. In this study, the dispersion of exhaled aerosols inside an NPIW was simulated using a validated CFD model. The impact of incorporating PACs in NPIWs on targeted aerosol removal, HCW passive exposure risk, wall deposition rates, and energy consumption was assessed. The energy consumption of the different ventilation modes was approximately estimated by calculating the load, which was determined by multiplying the running time of the ward by the time-averaged load. To evaluate the aerosol removal capacity of PACs, we propose a novel indicator called “TARGETINGPAC”. To gain a comprehensive understanding of various ventilation strategies in NPIWs, eight cases were simulated. The simulations revealed that the ceiling supply ceiling return ventilation mode is unsuitable for NPIWs. However, the introduction of PACs reversed the dispersion trend of aerosols in NPIWs, increasing the targeted aerosol removal capacity by 38.5%–62.5 %. Furthermore, PACs reduced the viral load on HCWs' body surfaces and on the walls of NPIWs while also improving energy efficiency by 12.6%–31.1 % in winter and summer.
Graphical abstract
Highlights
•Evaluated air cleaner aerosol removal ability in a negative-pressure isolation ward.
•TARGETINGPAC can assess the targeting aerosol removal performance of air cleaner.
•Placement of the portable air cleaner increased the TARGETING value by 62.5 %.
•Portable air cleaner can reduce the virus load on the body surface by 85.2%–88.8 %.
•Found between 12.6% and 31.1 % reduction in energy consumption due to air cleaners.
Abstract
During the COVID-19 pandemic, negative-pressure isolation wards (NPIWs) became a crucial infrastructure for treating patients and safeguarding healthcare workers (HCWs). However, the standard requirements for full fresh air and high air changes per hour (ACH) make NPIWs extremely energy-intensive. The blind ventilation design of NPIWs also poses potential exposure risks for HCWs. To address these issues, portable air cleaners (PACs) have been proven effective in removing bioaerosols from the air, providing a clean air delivery rate (CADR) without the need for additional fresh air load. In this study, the dispersion of exhaled aerosols inside an NPIW was simulated using a validated CFD model. The impact of incorporating PACs in NPIWs on targeted aerosol removal, HCW passive exposure risk, wall deposition rates, and energy consumption was assessed. The energy consumption of the different ventilation modes was approximately estimated by calculating the load, which was determined by multiplying the running time of the ward by the time-averaged load. To evaluate the aerosol removal capacity of PACs, we propose a novel indicator called “TARGETINGPAC”. To gain a comprehensive understanding of various ventilation strategies in NPIWs, eight cases were simulated. The simulations revealed that the ceiling supply ceiling return ventilation mode is unsuitable for NPIWs. However, the introduction of PACs reversed the dispersion trend of aerosols in NPIWs, increasing the targeted aerosol removal capacity by 38.5%–62.5 %. Furthermore, PACs reduced the viral load on HCWs' body surfaces and on the walls of NPIWs while also improving energy efficiency by 12.6%–31.1 % in winter and summer.
Graphical abstract