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At present, Dr. Alireza Afshari is a full Professor and Head of the Research Group Heating Ventilating and Air-Conditioning Research Group, in Department of the Built Environment, Aalborg University. Afshari has a background in building services engineering and has experience in the fields of indoor climate, and particles and filtration research. The vision of the research group is to provide energy-efficient solutions that improve atmospheric climate and thermal conditions in buildings. Moreover, the vision of the group is in line with the Danish government energy strategy and focuses on new buildings as well as existing buildings in order to improve the built environment.
Nanofibre filters may offer new properties not available in commercial fibre filters. These include a higher surface area and the ability to include novel materials within the fibres. In addition the small size allows potential gains in performance due to the slip-flow phenomenon in which normal gas viscosity does not apply to objects smaller than the mean free path of the gas. We tested the properties of novel electrospun fibre filters generated from polyvinyl alcohol solutions, optionally embedded with nano-grains of photocatalytic TiO2 and activated charcoal. The tested materials exhibited pressure drops in the range of 195 Pa to 2693 Pa for a face velocity of 5.3 cm/s and a removal efficiency greater than 97% for 12–480 nm particles. Basis weights for the filters ranged from 16.6 to 67.6 g/m2 and specific surface areas ranged from 1.4 to 17.4 m2/g. Reactivity towards volatile organic compounds (VOCs) was achieved by irradiating the photocatalytic filters with ultraviolet light. It is necessary to solve the problems connected to the absorbance of VOCs and further reduce the resistance to airflow in order for these filters to achieve widespread use. The incorporation of reactive air filtration into building ventilation systems will contribute to improved indoor air quality.
Roberta Orlando; Merve Polat; Alireza Afshari; Matthew Johnson; Peter Fojan. Electrospun Nanofibre Air Filters for Particles and Gaseous Pollutants. Sustainability 2021, 13, 6553 .
AMA StyleRoberta Orlando, Merve Polat, Alireza Afshari, Matthew Johnson, Peter Fojan. Electrospun Nanofibre Air Filters for Particles and Gaseous Pollutants. Sustainability. 2021; 13 (12):6553.
Chicago/Turabian StyleRoberta Orlando; Merve Polat; Alireza Afshari; Matthew Johnson; Peter Fojan. 2021. "Electrospun Nanofibre Air Filters for Particles and Gaseous Pollutants." Sustainability 13, no. 12: 6553.
Latent heat stored in phase change materials (PCM) can greatly improve energy efficiency in indoor heating/cooling applications. This study presents the materials and methods for the formation and characterization of a PCM layer for a latent heat thermal energy storage (LHTES) application. Four commercially available PCMs comprising the classes of organic paraffins and organic non-paraffins were selected for thermal storage application. Pure organic PCM and PCM in water emulsions were experimentally investigated. PCM electrospun microfibers were produced by a co-axial electrospinning technique, where solutions of Polycaprolactone (PCL) 9% w/v and 12% w/v in dichloromethane (DCM) were used as the fiber shell materials. PCM emulsified with sodium dodecyl sulfate (SDS), and Polyvinylalcohol 10% w/v (PVA) constituted the core of the fibers. The thermal behavior of the PCM, PCM emulsions, and PCM electrospun fibers were analyzed with differential scanning calorimetry (DSC). A commercial organic paraffin with a phase change temperature of 18 °C (RT 18) in its pure and emulsified forms was found to be a suitable PCM candidate for LHTES. The PVA-PCM electrospun fiber matrix of the organic paraffin RT18 with a PCL concentration of 12% w/v showed the most promising results leading to an encapsulation efficiency of 67%.
Evdoxia Paroutoglou; Peter Fojan; Leonid Gurevich; Göran Hultmark; Alireza Afshari. Thermal Analysis of Organic and Nanoencapsulated Electrospun Phase Change Materials. Energies 2021, 14, 995 .
AMA StyleEvdoxia Paroutoglou, Peter Fojan, Leonid Gurevich, Göran Hultmark, Alireza Afshari. Thermal Analysis of Organic and Nanoencapsulated Electrospun Phase Change Materials. Energies. 2021; 14 (4):995.
Chicago/Turabian StyleEvdoxia Paroutoglou; Peter Fojan; Leonid Gurevich; Göran Hultmark; Alireza Afshari. 2021. "Thermal Analysis of Organic and Nanoencapsulated Electrospun Phase Change Materials." Energies 14, no. 4: 995.
Many people spend most of their time in an indoor environment. A positive relationship exists between indoor environmental quality and the health, wellbeing, and productivity of occupants in buildings. The indoor environment is affected by pollutants, such as gases and particles. Pollutants can be removed from the indoor environment in various ways. Air-cleaning devices are commonly marketed as benefiting the removal of air pollutants and, consequently, improving indoor air quality. Depending on the type of cleaning technology, air cleaners may generate undesired and toxic byproducts. Different air filtration technologies, such as electrostatic precipitators (ESPs) have been introduced to the market. The ESP has been used in buildings because it can remove particles while only causing low pressure drops. Moreover, ESPs can be either in-duct or standalone units. This review aims to provide an overview of ESP use, methods for testing this product, the performance of existing ESPs concerning removing pollutants and their byproducts, and the existing market for ESPs.
Alireza Afshari; Lars Ekberg; Luboš Forejt; Jinhan Mo; Siamak Rahimi; Jeffrey Siegel; Wenhao Chen; Pawel Wargocki; Sultan Zurami; Jianshun Zhang. Electrostatic Precipitators as an Indoor Air Cleaner—A Literature Review. Sustainability 2020, 12, 8774 .
AMA StyleAlireza Afshari, Lars Ekberg, Luboš Forejt, Jinhan Mo, Siamak Rahimi, Jeffrey Siegel, Wenhao Chen, Pawel Wargocki, Sultan Zurami, Jianshun Zhang. Electrostatic Precipitators as an Indoor Air Cleaner—A Literature Review. Sustainability. 2020; 12 (21):8774.
Chicago/Turabian StyleAlireza Afshari; Lars Ekberg; Luboš Forejt; Jinhan Mo; Siamak Rahimi; Jeffrey Siegel; Wenhao Chen; Pawel Wargocki; Sultan Zurami; Jianshun Zhang. 2020. "Electrostatic Precipitators as an Indoor Air Cleaner—A Literature Review." Sustainability 12, no. 21: 8774.