Operation of air‐conditioning and sanitary equipment for SARS‐CoV‐2 infectious disease control

Abstract

It is still undetermined if the main infection route of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the virus that leads to coronavirus disease 2019 (COVID‐19), is infection through droplet, contact, or airborne transmission. However, confined spaces with poor ventilation are cited as a risk factor for group outbreaks, and there is growing interest in the effects of intervention through the appropriate operation of air‐conditioning and sanitary equipment to reduce the risk of airborne transmission. This study first offers an outline of the characteristics of the novel coronavirus disease and the cluster outbreak case reports that have been clarified until now. Subsequently, we describe the appropriate operating conditions for building equipment that are effective in reducing the risk of infection and also highlight specificities for each building use based on the guidance provided by healthcare institutions and with reference to the standard recommendations by Western academic societies related to building equipment.

Systematic summary and analysis of Chinese HVAC guidelines coping with COVID-19

“…Table 2 summarizes the fresh air volumes recommended during the normal and pandemic periods.

Figure 2.Operation schedule suggested by different guidelines (mostly for public buildings). 34,63–66

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“…In addition, there may be a lack of scientific and practical evidence on the suggestion of the use of return air, and further investigation is required. For the fresh air supply, Chinese guideline suggests that it should be not less than 30 m 3 /h/person; ASHRAE, a minimum ACH of 3 h; 62 REHVA, the CO 2 concentration should be less than 800 ppm (warning) 34 ; SHASE, a minimum supply of 30 m 3 /h/person and a minimum ACH of 2 h; 63 ISHRAE, 8.5 m 3 /h/person 64 ; and WHO, 36 m 3 /h/person. 65 These different numbers suggested by different countries are more or less close to each other, except for the ISHRAE from India.…”

“…Figure2. Operation schedule suggested by different guidelines (mostly for public buildings).34,[63][64][65][66] …”

Avaliação do projeto de ventilação natural de salas de aula durante a pandemia de Covid-19

“…A literatura existente aponta para a importância da renovação do ar interno como uma das principais estratégias de controle para a pandemia de Covid-19, ressaltando a necessidade de manutenção de taxas de renovação de ar mínimas (DIETZ, 2020;KURABUCHI et al, 2021). Tanto o ambiente físico como seus usuários devem se adaptar para uma nova realidade, com o apoio de evidências factuais e do conhecimento científico.…”

“…Tanto o ambiente físico como seus usuários devem se adaptar para uma nova realidade, com o apoio de evidências factuais e do conhecimento científico. Algumas pesquisas apontam para valores mínimos de referência, em termos de taxa de renovação do ar ambiente ou por pessoa, como forma de reduzir a concentração interna de CO2 e demais aerossóis (BLOCKEN et al, 2021;DECKER et al, 2021;HOU et al, 2021;KURABUCHI et al, 2021;PARK et al, 2021). É importante salientar que, em condições com uma taxa de ventilação constante, a probabilidade de infecção aumenta aritmeticamente à medida que o tempo de exposição aumenta (PARK et al, 2021), sendo os dados trazidos por estes estudos referentes a períodos típicos de ocupação de ambientes escolares.…”