Evangelos Belias | EPFL Graph Search

Evangelos BELIAS holds an EPFLinnovators fellowship and joined HOBEL as a doctoral assistant on November 1st, 2019. Before, he studied Civil Engineering at the Aristotle University of Thessaloniki and at Ecole Spéciale de Travaux Publics ESTP in Paris as an Erasmus student. During his studies, he focused on buildings' energy performance with a special interest in Phase Change Materials and the improvement of the thermal comfort in buildings.Besides his studies, he worked for two years as a Civil Engineer in the industry. Firstly, he served as Civil-Military Engineer in the Greek Army as part of his military service, where he produced many technical-economic studies and supervised various construction projects. Afterward, he moved to Paris, where he worked at SNCF on the HS2 project and at EDVANCE on the EPR2 construction project.In HOBEL, his main focus is the natural ventilation of buildings and the integration of IoT technologies in the HVAC control systems in order to improve the Indoor Environmental Quality in an energy-efficient way.Alongside his studies, he has always been an active part of school councils and students' unions. The main demands are the improvement of the education system and more funds for research.

Influence of outdoor air pollution on European residential ventilative cooling potential

Evangelos Belias, Dusan Licina

Residential ventilative cooling via natural ventilation is influenced by outdoor air pollution. However, relative to climate, outdoor air pollution is not comprehensively considered in determining the ventilative cooling potential of buildings. To assess the impact of outdoor air pollution on ventilative cooling potential, we coupled a longitudinal dataset of five outdoor air pollutants from 26 European cities with building energy simulations. We explored the importance of climate, five outdoor air pollutants, urbanization level (Urban vs Suburban), and proximity to traffic (Traffic vs Background). We found that ventilative cooling remains an effective strategy for passive cooling, as it was able to reduce the cooling demand by 17-100% depending on local climate and air pollution. Urban air pollution reduced the ventilative cooling potential across Europe on average by 24%. The reduction varied within cities - 13% for Suburban Background, 24% for Urban Background, 19% for Suburban Traffic, and 44% for Urban Traffic locations. PM2.5 and PM10 were the main limiting factors for the ventilative cooling in all location types, whereas O3 and NO2 were critical in the Background and Traffic locations accordingly. These results can be utilized by building designers, operators and other stakeholders to maximize the application of ventilative cooling in buildings.

ELSEVIER SCIENCE SA2023

Influence of Ambient Air Pollution on Natural Ventilation Potential in Europe

Evangelos Belias, Dusan Licina

When designed and operated adequately, natural ventilation (NV) can improve the buildings' energy efficiency and indoor environmental quality. There is a plethora of factors that limit the effectiveness of NV, such as the climate, surrounding buildings, noise, and ambient air pollution, especially in urban environments. Nevertheless, the existing NV potential (NVP) calculation methods are complex and difficult to be used. This study proposes a new methodology for quantifying the NVP by considering the exterior climate and ambient air pollution. This methodology analyzes climatic and ambient air quality data to estimate the NVP of urban and suburban sites of 27 European cities. The results reveal that the level of urbanization and proximity to traffic significantly influence the applicability of NV. Taking ambient air pollution into account reduces the climatic NVP on average: 11% for suburban background sites, 28% for suburban traffic sites, 22% for urban background sites, and 50% for urban traffic sites. Building designers can use the proposed methodology in the building design phase in order to implement the NV without increasing occupants' exposure to outdoor air pollution. The results of the statistical analysis can be used by the public authorities and the decision-makers to better consider the limitations and opportunities of the NV use by the building stock.

AMER SOC HEATING, REFRIGERATING AND AIR-CONDITIONING ENGS2022

Outdoor PM2.5 air filtration: optimising indoor air quality and energy

Evangelos Belias, Dusan Licina

Human inhalation exposure to fine particulate matter (PM2.5), including the PM2.5 of outdoor origin, predominantly occurs indoors. To limit outdoor PM2.5 penetration into buildings, ventilation standards often require the filtration of outdoor air with a minimum efficiency. Nevertheless, the PM2.5 filter selection recommended by the standards is based on the annual average outdoor concentrations without considering seasonal or diurnal fluctuations. This could result in a waste of energy or elevated indoor PM2.5 exposures. Representative outdoor PM2.5 data from 37 cities worldwide in conjunction with a simulated office building are used to examine the impact of filtration strategies on indoor PM2.5 levels and the fan’s energy consumption. Two energy-saving methods are tested: (1) the optimum filter selection that maintains the indoor PM2.5 below the World Health Organization’s (WHO) air quality guidelines; and (2) the baseline filter recommended by standards in combination with a filter bypass. Relative to a standard recommended baseline case, the two applied methods could reduce energy demand by between 4% and 17%. This indicates that the outdoor air is over-filtered in the majority of the investigated cities. In cities with low-to-moderate outdoor PM2.5 levels, using a filter bypass can be an effective energy conservation method without compromising PM2.5 exposures indoors.

2022