Methods for air cleaning and protection of building occupants from airborne pathogens

Abstract

a b s t r a c tThis article aims to draw the attention of the scientific community towards the elevated risks of airborne transmission of diseases and the associated risks of epidemics or pandemics. The complexity of the problem and the need for multidisciplinary research is highlighted. The airborne route of transmission, i.e. the generation of pathogen laden droplets originating in the respiratory tract of an infected individual, the survivability of the pathogens, their dispersal indoors and their transfer to a healthy person are reviewed. The advantages and the drawbacks of air dilution, filtration, ultraviolet germicidal irradiation (UVGI), photocatalytic oxidation (PCO), plasmacluster ions and other technologies for air disinfection and purification from pathogens are analyzed with respect to currently used air distribution principles. The importance of indoor air characteristics, such as temperature, relative humidity and velocity for the efficiency of each method is analyzed, taking into consideration the nature of the pathogens themselves. The applicability of the cleaning methods to the different types of total volume air distribution used at present indoors, i.e. mixing, displacement and underfloor ventilation, as well as advanced air distribution techniques (such as personalized ventilation) is discussed.

Effect of warm air supplied facially on occupants’ comfort

“…Indication of improved occupant performance with PV was reported in rooms at 26 C [4]. Another important advantage of PV is its potential to protect occupants against airborne pollutants [6]. Research shows that in rooms with mixing ventilation the use of PV will decrease the risk of airborne transmission of infectious agents and will be superior to total volume ventilation alone, such as mixing ventilation and under-floor ventilation [7,8].…”

Numerical investigation of air stability in space capsule under low gravity conditions

“…The applicability of the cleaning methods to the different types of total volume of air distribution used at present indoors, i.e. mixing, displacement and under floor ventilation, as well as advanced air distribution techniques (such as personalized ventilation) is discussed [7]. Besides, the importance of indoor air characteristics, such as temperature, relative humidity and velocity, for the efficiency of different ventilation methods is analyzed, taking into consideration the nature of the pathogens themselves [7,8].…”

“…mixing, displacement and under floor ventilation, as well as advanced air distribution techniques (such as personalized ventilation) is discussed [7]. Besides, the importance of indoor air characteristics, such as temperature, relative humidity and velocity, for the efficiency of different ventilation methods is analyzed, taking into consideration the nature of the pathogens themselves [7,8]. The effects of the ventilation system and moisture-buffering properties of the building fabrics on the stability of the indoor temperature and humidity are analyzed by means of long-term field measurements.…”

Sensing a Historic Low-CO2 Future

“…There has been parallel work targeted at reducing airborne pathogens in buildings. For example that by a team led by Peng Xu investigated the efficacy of ultraviolet irradiation of upper room air in this regard (Xu et al, 2003); and there has been more recent work reviewing various means of protecting occupants from airborne pathogens (Balashikov & Melikov, 2009). The latter notes that knowledge of the influence of RH on pathogenic bacteria is scant, while 40-60% RH is accepted as more lethal to non-pathogenic bacteria.…”