HVAC systems for environmental control to minimize the COVID-19 infection

Abstract

The outbreak of pneumonia caused by 2019 Novel Coronavirus arises significant concern for virus transmission and control. The control of the indoor environment or public-enclosed environment is crucial to reduce the risk of infection. Heating, ventilation, air-conditioning (HVAC) systems are used to create a healthy, thermal-comfort indoor environments. Thus, the rational use of HVAC systems is of great importance for the environmental control to reduce infection risk and to improve human wellbeing in the pandemic. In order to satisfy the requirement of better healthy environment and more thermal comfort performance of indoor ventilation system, prevention of indoor pollution is essential, especially considering the purpose of disease transmission resistance. This paper investigated the collective contagion events in enclosed spaces as well as engineering control against virus spread with ventilation systems for health-care facilities and public vehicles. Future challenges of HVAC design and control were discussed.

COVID-19, the Built Environment, and Health

“…These will need to balance thermal comfort, fresh air exchanges, and reducing energy use (Allen and Ibrahim 2021;Burridge et al 2021;Ferdyn-Grygierek et al 2019). Two examples of such an approach are supplying personal ventilation directly to people's individual breathing zones (say, at their workstations; Figure 3B) instead of ventilating the entire interior building space (Figure 3A) (Melikov 2020) and using precision HVAC based on localized monitoring and artificial intelligence guidance (Ding et al 2020).…”

A review of methods to reduce the probability of the airborne spread of COVID-19 in ventilation systems and enclosed spaces

“…The Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) both corroborate the removal of the viral particles via air exchange ( Centers for Disease Control and Prevention, 2021 ; Ding et al, 2020 ) and recommend increasing the fresh air supply as a straightforward way to decrease the concentration of the viral particles in an enclosed space. Air ionization may also be used to increase the removal rate of viral particles from an enclosed space by increasing filtration efficiency and particle deposition.…”

“…This is supported by inspection of Equations (2) , (3) ), where it may be seen that a change in the number concentration of quanta in a specified volume, or a change in the time interval will both affect the dosage an individual receives. Therefore, it is clear to see how the recommendations of the CDC and the WHO regarding the ventilation controls are effective towards addressing the concentration of the airborne particles and subsequently reduce the probability of infection ( Centers for Disease Control and Prevention, 2021 ; Ding et al, 2020 ). It is important to realize that depending on the type of enclosed space, there will typically be a natural ventilation corresponding to a number of Air Changes per Hour (ACH) between 0.34/hr – 20/hr, which may be considered as analogous to the removal rate ( Bazant and Bush, 2021 ).…”

“…However, if the humidity is higher than this range then the droplet will be less apt to evaporate, but the virus is more likely to survive due to the lower concentration of salts. If the humidity is lower than this range then the liquid droplet will evaporate and reduce in size, thus remaining airborne for a longer period of time and crystallizing the salts, removing their effect on the inactivation of the virus ( Ding et al, 2020 ; Yang et al, 2012 ). It is worth noting that although the survivability of the virus increased in both the upper and lower ranges compared to the ideal range in between, the upper range yielded a lower survivability than the lower range.…”

Analisis Pola Spasial Pesebaran Kasus Covid-19 Menggunakan Sistem Informasi Geografis Di DKI Jakarta

“…Hal ini dikarenkan proses penyebaran virus yang cepat, dari manusia ke manusia (Yanti, Nugraha, Wisnawa, Agustina, & Diantari, 2020). Selain itu, pandemi Covid-19 merupakan peristiwa yang mengakibatkan kematian tinggi, dan terdapat 216 negara yang telah melaporkan kasus infeksi Covid-19 (Ding, Yu, & Cao, 2020). Hal ini menunjukkan bahwa Covid-19 merupakan bencana yang dapat menggangu kelangsungan hidup manusia karena berdampak secara langsung pada kesehatan, ekonomi, dan permasalahan social budaya masyarakat (Hermon, 2020).…”