Mixing ventilation systems effectively improves thermal comfort in open-spaces due to adequate turbulent mixing of the cold stream with ambient air. This study introduces the concept of precision ventilation for achieving local thermal... more
Mixing ventilation systems effectively improves thermal comfort in open-spaces due to adequate turbulent mixing of the cold stream with ambient air. This study introduces the concept of precision ventilation for achieving local thermal comfort in a mixing ventilation system. This precision ventilation system provides asymmetrical airflows from an active chilled beam (ACB) to each of the office occupants. These ACBs provide air velocities with different magnitudes and directions. To achieve different magnitudes and directions, JetCones are used to vary the airflow in different parts of the ACB. The performance of the precision ventilation system was analyzed using full-scale laboratory experiments and computational fluid dynamic (CFD) simulations. The full-scale laboratory experiments were conducted in a 4.2 m × 3 m × 2.8 m (L × W × H) thermal isolated room with an open-plan dual desk-chair setup. The jet-cones in the ACB unit were adjusted to throw the required amount of flow to the...
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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... more
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. ...
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A variety of air filtration technologies are commercially available for reducing particles and gaseous contaminants that may enter buildings from outside. According to the World Health Organization (WHO), there is an increasing range of... more
A variety of air filtration technologies are commercially available for reducing particles and gaseous contaminants that may enter buildings from outside. According to the World Health Organization (WHO), there is an increasing range of adverse health effects linked to air pollution, at even-lower concentration of pollutants. This article presents a short literature overview of air filtration technologies, which focus on assessing their ability in removing both particles and gaseous compounds. The aim is to provide information about current research development of air filtration technologies as well as their advantages, limitations and performance in terms of removal efficiency, pressure drop and formation of by-products. Mechanical filters and electrostatic filters are efficiently used for the removal of particles. Photocatalytic oxidant and adsorbent air filters are commonly used for gas removal. These last two types of filters are not feasible for particles removal. Air filtratio...
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... Forskningscenter for Forebyggelse og Sundhed, Amtssygehuset i Glostrup Henrik N. Knudsen, Alireza Afshari og Carsten M. Pedersen Statens Byggeforskningsinstitut John Christian Larsen og Elsa Nielsen Danmarks Fødevareforskning... more
... Forskningscenter for Forebyggelse og Sundhed, Amtssygehuset i Glostrup Henrik N. Knudsen, Alireza Afshari og Carsten M. Pedersen Statens Byggeforskningsinstitut John Christian Larsen og Elsa Nielsen Danmarks Fødevareforskning Miljøprojekt Nr. 1097 2006 Page 2. ...
Tess welcomed the committee members and guests to the annual meeting: 1.1 Reminded everyone of the nomination year ahead. 1.2 Highlighted the conference sessions of interest to this committee (Appendix 3). 1.3 Expressed appreciation to... more
Tess welcomed the committee members and guests to the annual meeting: 1.1 Reminded everyone of the nomination year ahead. 1.2 Highlighted the conference sessions of interest to this committee (Appendix 3). 1.3 Expressed appreciation to Esin Sultan Oguz and the Turkey Library Association for hosting the mid-year meeting, which was a great success. 2. Document check Completed. 3. Round table – Introduction and sharing of projects/work Each person took the time to introduce themselves and also included a brief update on a project, passion or piece of work they have undertaken in the last year.
To control the emission of pollutants from building materials, labelling systems have been introduced. Some of the systems combine measurements of volatile organic compounds according to 16000-9 and sensory evaluations. In Denmark, the... more
To control the emission of pollutants from building materials, labelling systems have been introduced. Some of the systems combine measurements of volatile organic compounds according to 16000-9 and sensory evaluations. In Denmark, the sensory tests are performed by a minimum of 20 subjects. The subjects assess the air quality using a continuous acceptability scale and an odour intensity scale. In Germany the sensory evaluation system is being developed. The volumetric flow in the chambers is too low for direct sensory evaluation. Thus a system is developed to sample the air from air sampling bag. The air is evaluated by a panel of at least 10 persons using a reference scale. For the Finnish M1 label the sensory evaluations are performed by 5 to 10 subjects assessing air quality using a continuous acceptability scale and describing the odour using a list of odour profiles. The purpose of the present paper is to compare and discuss the sensory test procedures of the different labelli...
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Recruitment and selection of competent personnel are essential for the ongoing success of any project based organization (PBO). The key issue for decision making in personnel recruitment is selection of the right person to the right job.... more
Recruitment and selection of competent personnel are essential for the ongoing success of any project based organization (PBO). The key issue for decision making in personnel recruitment is selection of the right person to the right job. Although both are closely interrelated parts of a multistage decision process, recruiting activities generate applicants for jobs, and selection decisions must then be made that attempt to choose the subset of applicants, or the applicant, most likely to succeed. The main objective of this study is to develop a model based on PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluation) method for ranking personnel selection criteria. In this study, a decision making methodology is designed that employs PROMETHEE in order to help the personnel selection process. In this respect, the aim of using the PROMETHEE technique is taken into account to assess and rank the importance of criteria.
The success or failure of a project in achieving predefined objectives is largely dependent on the suitability of its execution system. An important decision in the early stages of a project is to investigate different possible ways for... more
The success or failure of a project in achieving predefined objectives is largely dependent on the suitability of its execution system. An important decision in the early stages of a project is to investigate different possible ways for executing projects and selecting the best one. This requires the identification of risk taking of projects. Risk is, in fact, the same as uncertainty and a multidimensional concept affecting the project's objectives. Risk management is defined as the risk identification and assessment process and application of specific methods to reduce risks to an acceptable level. Therefore, the initial objective of project risk management is risk identification, evaluation and control for the success of projects. The risk management standard published by the Project Management Institute (PMI), entitled Project Management Body of Knowledge (PMBOK) was used in this study as the basic method for describing risk management. The general objective of this study wa...
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Air filters are crucial components of a building ventilation system that contribute to improving indoor air quality, but they are typically associated with relatively high pressure drops. The purpose of the study is to evaluate the effect... more
Air filters are crucial components of a building ventilation system that contribute to improving indoor air quality, but they are typically associated with relatively high pressure drops. The purpose of the study is to evaluate the effect of additives on ultrathin electrospun filters, the pressure drop, and the particle removal efficiency of uniformly charged particles. The fibres were electrospun under optimised conditions that resulted in a fast-fabricating process due to the properties of the cellulose acetate solution. Different ultrathin electrospun fibre filters based on cellulose acetate (CA) were fabricated: a pure CA electrospun fibre filter, two filters based on CA fibres separately doped with activated charcoal (AC) and titanium dioxide (TiO2), respectively, and a composite filter where the two additives, AC and TiO2, were embedded between two CA fibres layers. The ultrathin filters exhibited a low pressure drop of between 63.0 and 63.8 Pa at a face velocity of 0.8 m s−1....
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Urban Building Energy Simulation (UBES) is an efficient tool to investigate and subsequently reduce energy demand of urban areas. Nevertheless, UBES has always been a challenging task due the trade-off between accuracy, computational... more
Urban Building Energy Simulation (UBES) is an efficient tool to investigate and subsequently reduce energy demand of urban areas. Nevertheless, UBES has always been a challenging task due the trade-off between accuracy, computational speed and parametrization. In order to reduce these computation and parameterization requirements, model reduction and simplification methods aim at representing building behaviour with an acceptable accuracy, but using less equations and input parameters. This paper presents the development and validation results of a simplified urban simulation model based on the ISO 13790 Standard and written in the Modelica language. The model describes the thermo-physical behaviour of buildings by means of an equivalent electric network consisting of five resistances and one capacitance. The validation of the model was carried out using four cases of the ANSI/ASHRAE Standard 140. In general, the model shows good accuracy and the validation provided values within th...
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Abstract Iron and copper are two essential micronutrients that play important roles in vital biological processes, key enzymes and the immune system. In this study, the effects of diet supplementation with inorganic and nanoparticulate... more
Abstract Iron and copper are two essential micronutrients that play important roles in vital biological processes, key enzymes and the immune system. In this study, the effects of diet supplementation with inorganic and nanoparticulate iron and copper on growth performance and hemato-immunological responses of snow trout Schizothorax zarudnyi (23.97 ± 0.45 g) were investigated for 84 days. The fish were fed by seven experimental diets supplemented with 0 mg copper and iron (Cu, Fe) (control), 150 mg inorganic iron (FeI), 3 mg inorganic copper (CuI), 150 mg FeI and 3 mg CuI (FeI + CuI), 150 mg nanoparticulate iron (FeNPs), 3 mg nanoparticulate copper (CuNPs), 150 mg FeNPs and 3 mg CuNPs (FeNPs+CuNPs) per kg of diet. The results showed that the diet supplementation with Fe and Cu improved the growth and feeding indices compared with the control treatment; however, the nanoparticulate Fe and Cu acted more effectively than their inorganic counterparts. The values pertaining to the most hematological parameters, such as RBCs, hematocrit and hemoglobin, were higher in nanoparticulate treatments than in the inorganic ones (P
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AbstractThis paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate... more
AbstractThis paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally introduce pressure drops in the duct system thus nominal airflows are achieved throughout the ductwork within specified tolerances. However, introduction of pressure drops will increase energy requirement for the ventilation system and in addition, balancing a duct system is a time consuming task and often flawed. This paper presents a new procedure for balancing of C AV systems in combination with decentralised fans. The new system was based on replacing the balancing dampers with decentralised fans. By replacing the balancing dampers with decentralised fans, airflows can be balanced by adjusting the speed of the fans. In conventional air distribution systems the fan provides the necessary pressure to overc...
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Discharge coefficient and wind-pressure coefficient are the key input parameters for estimating the airflow rates in naturally ventilated building designs. This paper focuses on the study of the discharge coefficient (CD) in case of a... more
Discharge coefficient and wind-pressure coefficient are the key input parameters for estimating the airflow rates in naturally ventilated building designs. This paper focuses on the study of the discharge coefficient (CD) in case of a moveable (bottom-hinged) window flap. Computational fluid dynamics (CFD) techniques are used for estimating the coefficient. Focus is given to the window on the windward side of the building. The first objective of this study is to validate the k-ε turbulent model for the estimation of airflow rates through the window. It is done by comparing the numerical results with existing results of full-scale measurements under a laboratory conditions. The second objective is to find an accurate method to estimate the airflow rate (using orifice plate equation) in the case of a window with a moveable flap. It is done by using CFD predictions together with the validated turbulent model. A single value of CD (usually 0.6 to 0.65) is not appropriate for the operabl...
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Research Interests: Engineering, Earth Sciences, Materials Science, Indoor Air Quality, Housing, and 14 moreEnvironmental Monitoring, Medicine, Activities of Daily Living, Humans, Cooking, Hygiene, Indoor air pollution, Particle Size, Ultrafine Particles, Air Pollutants, Indoor air, Indoor climate, tobacco smoke pollution, and Medical and Health Sciences
This project is part of a long-term research program to study the possibilities of using efficient air-cleaning technologies to improve indoor air quality in buildings. The purpose of this part of the project was to study the... more
This project is part of a long-term research program to study the possibilities of using efficient air-cleaning technologies to improve indoor air quality in buildings. The purpose of this part of the project was to study the energy-saving potential of combining the cooling and cleaning of air in offices. For this purpose, a mechanical filter with low-pressure drop was selected for testing in a laboratory environment. The measurements included tests of the filter in ductwork to study the efficiency of the filter. Moreover, the combined system of the filter and a chilled beam was tested in a room. The efficiency of the mechanical filter to remove ultrafine particles was examined using pure wax candles and salt as sources of emission particles. The measurements in the duct showed that the efficiency of the filter ranged between 54% and 78% and that the pressure loss was less than 5 Pa (0.104 Ibf/ft2). Furthermore, the measurement results of the combined system showed that adding the filter accelerated the removal rate of the particles by 2 h−1. However, the efficiency of the chilled beam in exchanging heat was reduced by 38%.
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The emission of di-2-ethylhexyl phthalate (DEHP) from a PVC flooring was studied for up to 472 days in both the FLEC (Field and Laboratory Emission Cell) and the CLIMPAQ (Chamberfor Laboratory Investigations of Materials, Pollution, and... more
The emission of di-2-ethylhexyl phthalate (DEHP) from a PVC flooring was studied for up to 472 days in both the FLEC (Field and Laboratory Emission Cell) and the CLIMPAQ (Chamberfor Laboratory Investigations of Materials, Pollution, and Air Quality). The loading of the CLIMPAQs was varied but was constant in the FLECs. The sorption properties of FLEC and CLIMPAQ were investigated using different methods. In addition, the uptake of DEHP by office floor dust on the PVC flooring was studied in CLIMPAQ experiments. The concentration versus time curves in both FLECs and CLIMPAQs increased slowly over about 150 days and reached a quasi-static equilibrium at 1 microg m(-3). The main conclusions were that (i) the emission rate of DEHP was limited by gas-phase mass transport and (ii) the dust layer increased the emission rate by increasing the external concentration gradient above the surface of the PVC. These conclusions were based on the facts that the specific emission rate was inversely proportional to the loading and that the dust had sorbed about four times as much DEHP over a 68-day period as emitted in the gas-phase experiments. About one-half of the emitted DEHP was deposited on the internal surfaces of both the FLEC and the CLIMPAQ.