The influence of ventilation on indoor air quality in buildings with variable pollutant emissions

Abstract

Indoor Air Quality (IAQ) assurance is done mainly through the air exchange between interior and exterior. Lack of adequate ventilation of indoor spaces causes poor air quality and a higher incidence of sick building syndrome (SBS), which is manifested by affecting the comfort and wellbeing in the indoor spaces. Ensuring high energy performance buildings and indoor air quality is efficiently approached by limiting emissions from sources, by partial neutralization of the pollutants or by smarter ventilation. The concept of smart ventilation was developed to ventilate properly while reducing energy loads, allow for the provision of grid services, and promote associated renewable power integration. The above-mentioned information can be obtained by the air quality modelling, using mathematical approaches to predict the way pollutants behave in a certain environment or time scale. The paper presents the results obtained by mathematical modelling of indoor air quality, by including the transfer of pollutants from external sources and variable indoor emissions. The considered pollutants are ozone (O3), particulate matter (PM2.5), formaldehyde (HCHO) and carbon dioxide (CO2), due to the significant adverse effects on human health and their different preponderantly sources: indoor, outdoor or both indoor and outdoor. The main goal of our researches is the reducing of the amount of energy that ventilation uses while maintaining or improving IAQ.

The Relationship between Mechanical Ventilation, Indoor Air Quality Classes, and Energy Classes in a Romanian Context

“…The volume of the indoor space was 180 m 3 . The indoor pollutant concentration, C i , was obtained by using the monitored experimental data on the outdoor pollutant concentration, C o , for each of the four selected pollutants for a period of 93 h (5580 min), as we described in [39]. The time step, ∆τ, was of 1 h.…”

“…As previously mentioned, the first stage of our research focused on the mathematical modeling of indoor air quality [39] in a climatized thermal zone (ZTC). The indoor space has a volume, V, and inside, we assumed a uniformly distributed concentration of pollutant, Ci.…”

“…This equation is further developed by introducing the outdoor concentration, C o , the indoor concentrations, C i , and the filters F 0 and F 1 . After successive processing (shown in extenso in [39]), the solution of the equation is…”

“…where S and R represent the sources and loss terms, and the left term of the represents the pollutant increase indoors. This equation is further developed by i ing the outdoor concentration, Co, the indoor concentrations, Ci, and the filters F After successive processing (shown in extenso in [39]), the solution of the equati While the indoor pollutant concentration is variable from one time step to another, the other parameters (q 1 , q 2 , C o , C i , F 0 , F 1 , S, R) are constant during the time interval between the time steps (τ) and (∆τ).…”

“…According to the majority of research studies, a large range of pollutants can be found in indoor spaces. In this respect, based on [7,23,39,[41][42][43] and on the energy classes idea from [21], eight indoor air quality classes were designed for each of the four studied pollutants.…”