Minimizing the COVID-19 spread in hospitals through optimization of ventilation systems

Abstract

The rapid spread of SARS-CoV-2 virus has overwhelmed hospitals with patients in need of intensive care, which is often limited in capacity and is generally reserved for patients with critical conditions. This has led to higher chances of infection being spread to non-COVID-19 patients and healthcare workers and an overall increased probability of cross contamination. The effects of design parameters on the performance of ventilation systems to control the spread of airborne particles in intensive care units are studied numerically. Four different cases are considered, and the spread of particles is studied. Two new criteria for the ventilation system—viz., dimensionless timescale and extraction timescale—are introduced and their performances are compared. Furthermore, an optimization process is performed to understand the effects of design variables (inlet width, velocity, and temperature) on the thermal comfort conditions (predicted mean vote, percentage of people dissatisfied, and air change effectiveness) according to suggested standard values and the relations for calculating these parameters based on the design variables are proposed. Desirability functions that are comprised of all three thermal condition parameters are used to determine the range of variables that result in thermally comfortable conditions and a maximum desirability of 0.865 is obtained. The results show that a poorly designed ventilation system acts like a perfectly stirred reactor—which enormously increases the possibilities of contamination—and that when air is injected from the ceiling and extracted from behind the patient beds, the infection spread is least probable since the particles exit the room orders of magnitude faster.

Hospital Outdoor Spaces as Respite Areas for Healthcare Staff During the COVID-19 Pandemic

“…Second, the virus is highly contagious, airborne, and has led to over 6.7 million deaths globally, thereby heightening fears over risk to the health of hospital staff, social isolation, and the associated “infection stigma” from the public (Galbraith et al, 2021; Mukhtar, 2020). For example, poorly designed hospital ventilation systems increase the possibility of spreading the COVID-19 virus to other patients and healthcare workers (Arjmandi et al, 2022). Another stressor is the need to provide quality healthcare to patients, often under pressure and through overload and multiple rotating shifts, while balancing their safety and the safety of their family members (Elkholy et al, 2020, Wasim et al, 2020).…”

“…Healthcare policy makers and relevant government agencies should also prioritize the long-term goal of implementing evidence-based design considerations for hospitals (Arjmandi et al, 2022; Iqbal, 2021a). This design approach is based on evaluating all hospital users’ design, environmental, and psychological needs (Sachs, 2017).…”

Analysis of the spread of SARS-CoV-2 in a hospital isolation room using CFD and Lagrangian Coherent Structures

“…Arjmandi et al. (2022) [6] used CFD to examine how various factors affect the effectiveness of ventilation systems in reducing the transmission of SARS-CoV-2 in an intensive care unit (ICU) room. The study identified two ventilation criteria, namely the dimensionless timescale (T) and extraction timescale ( ), and concluded that poor ventilation systems can increase the risk of contamination, as they behave like a perfectly stirred reactor.…”

Inactivation characteristics of a 280 nm Deep-UV irradiation dose on aerosolized SARS-CoV-2

“…The key to controlling viral infections is to reduce the virus concentration in living spaces ( Tang et al, 2020 ). In crowded spaces (e.g., classrooms [ Foster and Kinzel, 2021 , Narayanan and Yang, 2021 , Zimmerman et al, 2021 ], offices, hospital waiting rooms [ Arjmandi et al, 2022 ], and trains [ Woodward et al, 2021 ]), the virus present in the human breath fills the spaces and increases the risk of infection. To reduce the infection risk, several reports indicate the importance of outdoor ventilation with open windows or air-conditioned ventilation to let in outdoor air ( Morawska and Milton, 2020 , Park et al, 2019 , Elsaid et al, 2021 ).…”