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Articles 781 - 810 of 1689

Full-Text Articles in Engineering Physics

Thermal Performance Analysis Of Traditional Housing In Albania, Rudina Belba, Sokol Dervishi Sep 2018

Thermal Performance Analysis Of Traditional Housing In Albania, Rudina Belba, Sokol Dervishi

International Building Physics Conference 2018

This paper introduces the results of a one-year research, to gather and analyse data on the traditional housing buildings in Kukes region, Albania. The energy performance and the thermal comfort conditions in five different buildings were examined. The Design Builder Energy simulation software was used to analyse the thermal performance of the selected typologies. Detailed construction activity and weather information was applied in modelling the houses. Simulation results showed that these buildings require only heating during the winter. As for the first villa, seven improvement scenarios were applied and examined. The same scenarios incorporate the use of thermal insulation of …

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Effect Of Urban Texture On Building Energy Performance, Suzi Dilara Mangan, Irem Sozen, Gul Koclar Oral, Idil Erdemir Kocagil Sep 2018

Effect Of Urban Texture On Building Energy Performance, Suzi Dilara Mangan, Irem Sozen, Gul Koclar Oral, Idil Erdemir Kocagil

International Building Physics Conference 2018

Today, ongoing discussions on climate change, depletion of fossil fuels and energy efficiency emphasize the need for a more sustainable built environment and thus the need to reduce energy consumption in buildings and urban textures and reduce greenhouse gas emissions. Therefore the evaluation of building energy performance with a holistic approach, taking the effect of urban textures and microclimates into consideration has become very significant in the recent years. Urban texture is a commonly accepted expression including the form and height of buildings, the width of streets, their orientation, spatial configuration and arrangement in space intersection, vegetation and so on. …

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Using Advanced Urban Canopy Models To Investigate The Potential Of Thermochromic Materials As Urban Heat Island Mitigation Strategies, Claudia Fabiani, Anna Laura Pisello, Elie Bou-Zeid, Jiachuan Yang Sep 2018

Using Advanced Urban Canopy Models To Investigate The Potential Of Thermochromic Materials As Urban Heat Island Mitigation Strategies, Claudia Fabiani, Anna Laura Pisello, Elie Bou-Zeid, Jiachuan Yang

International Building Physics Conference 2018

Recent trends in urbanization processes are causing serious threats at both local and global environmental scale. Greenhouse gas emissions, heat waves, and the heat island effect are constantly growing in intensity and produce increasing discomfort and health impacts in urban populations. In this context, the building sector is currently developing advanced and adaptive materials for building envelope and paving surface applications characterized by high energy performance and low embodied energy. Most of these innovative materials are firstly analysed at the component scale by means of laboratory investigations, while their effect on the built environment is generally assessed at a later …

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Rapid Cooling Of Urban Surfaces During Rainfall: Physical Basis, Dominant Energy Fluxes, And Sensitivity To Pavement And Rainfall Properties, Hamidreza Omidvar, Elie Bou-Zeid Sep 2018

Rapid Cooling Of Urban Surfaces During Rainfall: Physical Basis, Dominant Energy Fluxes, And Sensitivity To Pavement And Rainfall Properties, Hamidreza Omidvar, Elie Bou-Zeid

International Building Physics Conference 2018

Using model for the heat transfer between pavements and runoff during rainfall, we investigate the importance of different pavement and rainfall properties, as well as crucial energy budget terms that drive the cooling processes. The results indicate that the pavement and runoff temperature and energy fluxes are very sensitive to the rain temperature. In addition, pavement albedo has a significant effect on the simulated temperature since it modifies the initial pavement temperature before the rain starts. The results also indicated that among the different energy budget terms, evaporation and long wave radiation are the main cooling terms, while the shortwave …

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Analytical And Numerical Investigation On Depth And Pipe Configuration For Coaxial Borehole Heat Exchanger, A Preliminary Study, Hongshan Guo, Forrest Meggers Sep 2018

Analytical And Numerical Investigation On Depth And Pipe Configuration For Coaxial Borehole Heat Exchanger, A Preliminary Study, Hongshan Guo, Forrest Meggers

International Building Physics Conference 2018

Existing research on the performance of shallow geothermal systems are prone to investigate the ground as a large thermal mass at a constant temperature despite possible temperature increase at depths - otherwise commonly known as the geothermal gradient. Most of the existing analytical models that predict the heat exchange between a borehole heat exchanger with the soil does not allow for the geothermal gradients to be accounted for. The few models that actually does account for the geothermal gradients, on the other hand, does so by enforcing a pre-existing temperature gradient only. We are presenting a bottom up approach in …

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Comparison Of Lattice Boltzmann Method And Finite Volume Method With Large Eddy Simulation In Isothermal Room Flow, Mengtao Han, Ryozo Ooka, Hideki Kikumoto Sep 2018

Comparison Of Lattice Boltzmann Method And Finite Volume Method With Large Eddy Simulation In Isothermal Room Flow, Mengtao Han, Ryozo Ooka, Hideki Kikumoto

International Building Physics Conference 2018

Lattice Boltzmann method (LBM), as a new computational fluid simulation method, has aroused widespread attention in recent decades within engineering practice. LBM with large eddy simulation (LBM-LES) model is commonly used in predicting high Reynolds flow, and is considered to have a prediction accuracy similar to traditional finite volume method (FVMLES). Nonetheless, a systematic discussion on the accuracy of LBM-LES, and its consistency with FVM-LES, in indoor turbulent flow situations, is still insufficient. In this study, simulations of an indoor isothermal forced convection benchmark case (from IEA Annex 20) are implemented by using both LBM-LES and FVM-LES, with the aim …

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Development Of A Supermarket Prototype Building Model, Piljae Im, Brian A. Fricke, Joshua R. New, Mark B. Adams Sep 2018

Development Of A Supermarket Prototype Building Model, Piljae Im, Brian A. Fricke, Joshua R. New, Mark B. Adams

International Building Physics Conference 2018

The U.S. Department of Energy supports the development of commercial building energy codes and standards by participating in industry reviews, update processes, and providing technical analyses to support both published model codes and potential changes. In support of ANSI/ASHRAE/IES Standard 90.1 and the International Energy Conservation Code, 16 commercial prototype building models were developed that cover 80% of the commercial building floor area in the United States for new construction, including both commercial buildings and mid- to high-rise residential buildings, across all U.S. climate zones. However, the current set of commercial prototype building models does not include a supermarket building …

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House: Building Energy Efficiency Understanding Through An Enabled Boundary Object, Deborah Adkins, Peter R.N. Childs Sep 2018

House: Building Energy Efficiency Understanding Through An Enabled Boundary Object, Deborah Adkins, Peter R.N. Childs

International Building Physics Conference 2018

We report the results of an empirical study on an enabled application’s ability to act as a boundary object and build understanding of energy efficiency solutions. Combining digital and tangible technology with radio-frequency identification (RFID) tags, we have created an interactive, digitally enabled device and application called HOUSE (Home User and Stakeholder Environment). The HOUSE tool and application have been designed and developed to support interaction and collaboration in the exploration of domestic energy efficiency solutions. HOUSE allows users to associate information with physical representations, and to explore this information through manipulation of enabled objects. The interactive application consists of …

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The Influence Of Window Opening Habits On The Residential Energy Use In Nearly Zero Energy Buildings, Silke Verbruggen, Marc Delghust, Jelle Laverge, Arnold Janssens Sep 2018

The Influence Of Window Opening Habits On The Residential Energy Use In Nearly Zero Energy Buildings, Silke Verbruggen, Marc Delghust, Jelle Laverge, Arnold Janssens

International Building Physics Conference 2018

In this paper, we discuss the presence of habits in the window opening behaviour of social housing tenants in a nearly zero-energy development in Belgium. A window opening habit can be defined as an action with a window that is repeated daily around the same time independently of the prevailing weather conditions. A carbon neutral social housing estate (106 apartments and 90 single family dwellings) was used as a test case. Questionnaires, window opening logging with a building monitoring system and cross-sectional surveys were used to collect window opening data. A method to identify window opening habits is determined. Up …

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Achieving Faster Building Energy Model Optimization Through Selective Zone Elimination, Zixiao Shi, Scott Bucking, William O'Brien Sep 2018

Achieving Faster Building Energy Model Optimization Through Selective Zone Elimination, Zixiao Shi, Scott Bucking, William O'Brien

International Building Physics Conference 2018

Optimization in building performance simulation (BPS) has become increasingly important due to the growing need for high-performance building design and operation. Numerous research efforts have been dedicated to decreasing optimization runtime by introducing improved optimization algorithms and advanced sampling techniques. This paper presents a novel model order reduction (MOR) algorithm tailored for speeding up building energy simulation. The algorithm identifies archetype zones simplifying the needless repetition of thermal zones. For an entire optimization process, this MOR method can be repeated recursively to reproduce reduced models. The proposed method can be used to speed up large-scale simulations including optimization, uncertainty analysis …

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Optimization Of Night Cooling Of Commercial Premises Using Genetic Algorithms And Neural Networks, Emmy Dahlström, Linus Rönn, Angela Sasic Kalagasidis Sep 2018

Optimization Of Night Cooling Of Commercial Premises Using Genetic Algorithms And Neural Networks, Emmy Dahlström, Linus Rönn, Angela Sasic Kalagasidis

International Building Physics Conference 2018

This paper investigates if it is possible to optimize night cooling control setpoints and ventilation schedule regarding energy consumption and indoor climate. A retail store, located in Gothenburg, was used as a case study. The investigation was done by numerical modelling and simulations. It started with development and calibration of a building energy model for the store with data collected from the field. Afterwards, the calibrated model was used in the optimization of the night cooling. Initially, a genetic algorithm was applied to find the global minimum of the problem and further refined with a local search algorithm. The optimization …

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Determination Of Lead Dust Fall Rates During Deconstruction Of Wood Frame Buildings In An Urban Region In The Northeastern United States, Paul Crovella, Marc Delaney, Melisa Kohan Sep 2018

Determination Of Lead Dust Fall Rates During Deconstruction Of Wood Frame Buildings In An Urban Region In The Northeastern United States, Paul Crovella, Marc Delaney, Melisa Kohan

International Building Physics Conference 2018

Title: Lead dust fall deposition rates during deconstruction of wood frame buildings in an urban region in the Northeastern United States. Objectives: Determine the lead dust fall deposition rate due to hybrid deconstruction (separation and removal of building components) of wood-frame structures, and compare that to the lead dust fall deposition rate from demolition (compression and collapse of building components). Scope: A city block with a total of 11 wood-frame structures was selected as the location for the deconstruction leadfall testing. Testing was done during the deconstruction of 7 of the 11 pre-1950 homes (mean construction year 1928, mean floor …

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Hygrothermal Performance Of A Hygroscopic And Permeable Wall Assembly: Impact Of A Vented Wall Cavity, Diane Bastien, Martin Winther-Gaasvig Sep 2018

Hygrothermal Performance Of A Hygroscopic And Permeable Wall Assembly: Impact Of A Vented Wall Cavity, Diane Bastien, Martin Winther-Gaasvig

International Building Physics Conference 2018

Building envelopes that are hygroscopic and permeable to water vapour can contribute to improve the Indoor Environmental Quality (IEQ) in buildings by reducing indoor humidity fluctuations and the concentration of some contaminants like CO2. However, risks of interstitial condensation and mold growth need to be assessed to ensure the durability of such building envelopes. The objective of this paper is to perform hygrothermal simulations of a case study house designed with a Hygroscopic and Permeable Building Envelope (HPBE) and to assess the impact of having a vented cavity compared to a face-sealed wall. This contribution presents hygrothermal simulations of a …

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Improving Durability Of Wooden Beam Bearings In Inside Insulated Walls By Tempering The Beam’S Heads, Paul Wegerer, Thomas Bednar Sep 2018

Improving Durability Of Wooden Beam Bearings In Inside Insulated Walls By Tempering The Beam’S Heads, Paul Wegerer, Thomas Bednar

International Building Physics Conference 2018

Improving durability of wooden beam bearings after a thermal renovation via interior insulation is highly demanding for planners. Because of an isolated thermal bridge in the area of the wooden beam head the risk of condensation water forming in this area increases after installing interior insulation. The problem with wooden beam ends has been analysed increasingly in the last few years by many research institutions as wooden ceiling constructions are common in existing buildings. Furthermore, thermal renovation makes a vital contribution regarding improving the energy-efficiency of existing buildings. In this paper a method to temper wooden beam ends is introduced. …

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Understanding Swelling Of Wood Through Multiscale Modeling, Dominique Derome, Chi Zhang, Mingyang Chen, Jan Carmeliet Sep 2018

Understanding Swelling Of Wood Through Multiscale Modeling, Dominique Derome, Chi Zhang, Mingyang Chen, Jan Carmeliet

International Building Physics Conference 2018

Wood is a well-used building material where the capacity of wood to absorb water leads to swelling and reduced mechanical properties, and also to questions of durability. The origin of the hygroscopic behavior of wood lies at the nanoscale material that composes its cell walls. Using atomistic modeling, we study the hygromechanical behavior of the different polymeric components of wood, separately and in aggregate configurations. We report the coupled effects of water sorption on the hygric and mechanical properties of the S2 cell wall layer and we upscale the findings using a poromechanical framework.

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Sorption Hysteresis In Wood And Its Coupling To Swelling: A New Modelling Approach, Jan Carmeliet, Mingyang Chen, Dominique Derome Sep 2018

Sorption Hysteresis In Wood And Its Coupling To Swelling: A New Modelling Approach, Jan Carmeliet, Mingyang Chen, Dominique Derome

International Building Physics Conference 2018

Sorption hysteresis of amorphous cellulose is studied. Cellulose, as a renewable organic biopolymer, is an essential component of various natural composites such as wood. A coupling process between sorption and deformation leads to the hysteresis as observed in sorption and swelling, both experimental and simulated for cellulose and wood in general.

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Analysis Of Dynamic Variation Characteristics And Influential Factors Of Pm2.5 On Subway Platforms Under Air-Conditioning Condition And Ventilation Condition, Lihui Wang, Jihua Zhang, Tianwei Hu, Meng Kong, Jensen Zhang, Jie Song, Yi Zheng Sep 2018

Analysis Of Dynamic Variation Characteristics And Influential Factors Of Pm2.5 On Subway Platforms Under Air-Conditioning Condition And Ventilation Condition, Lihui Wang, Jihua Zhang, Tianwei Hu, Meng Kong, Jensen Zhang, Jie Song, Yi Zheng

International Building Physics Conference 2018

The purpose of this study is to investigate the main influential factors of the subway Particulate Matter (PM) pollutants under the air-conditioning condition and ventilation condition, by an on-site field measurement in a subway station in Shanghai. It is found that the dust accumulation at fresh air shaft was the secondary dusting action under the influence of fresh air flow, leading to a higher concentration of the PM in the subway station than in the outdoor air even when the outdoor air quality was good. In addition, in the morning rush hour the PM 2.5 value near the platform screen …

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An Investigation On The Quantitative Correlation Between Urban Morphology Parameters And Outdoor Ventilation Efficiency Indices, Wowo Ding, Yunlong Peng, Zhi Gao Sep 2018

An Investigation On The Quantitative Correlation Between Urban Morphology Parameters And Outdoor Ventilation Efficiency Indices, Wowo Ding, Yunlong Peng, Zhi Gao

International Building Physics Conference 2018

Urban outdoor ventilation and pollutant dispersion have important implications for the urban planning and design of urban morphology. In this paper, two urban morphology parameters including Floor area ratio (FAR) and Building site coverage (BSC) are attempted to investigate the quantitative correlation with urban ventilation indices. Firstly, we present an idealized model including nine basic units. The FAR of model is constant 5.0, and the BSC increases from 11% to 77%, which in consequence generates 101 non-repetitive asymmetric forms. Next, the Computational Fluid Dynamics (CFD) is employed to evaluate the ventilation efficiency of pedestrian level within each model’s central area. …

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Utilization Of Heat Recovery Ventilation: Steady-State Two-Zone Heat Loss Analysis And Field Studies, Arnold Janssens, Wolf Bracke, Marc Delghust, Eline Himpe, Silke Verbruggen, Jelle Laverge Sep 2018

Utilization Of Heat Recovery Ventilation: Steady-State Two-Zone Heat Loss Analysis And Field Studies, Arnold Janssens, Wolf Bracke, Marc Delghust, Eline Himpe, Silke Verbruggen, Jelle Laverge

International Building Physics Conference 2018

In new houses in Europe the share of mechanical ventilation with heat recovery is increasing as a result of more severe energy performance requirements and of energy labelling for residential ventilation units. The methods used to assess the influence of heat recovery ventilation on the heating energy use in energy labelling and certification are typically based on single zone energy balance equations, although heating behaviour and set-points differ in different rooms of a dwelling. As a result of this the energy savings of heat recovery ventilation as assessed with single zone methods may be larger than when the spatial variations …

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Comparison Of Data-Driven Building Energy Use Models For Retrofit Impact Evaluation, Yujie Xu, Azizan Aziz, Bertrand Lasternas, Vivian Loftness Sep 2018

Comparison Of Data-Driven Building Energy Use Models For Retrofit Impact Evaluation, Yujie Xu, Azizan Aziz, Bertrand Lasternas, Vivian Loftness

International Building Physics Conference 2018

A change-point (piecewise linear regression) model fitted to the pre-retrofit data as the counterfactual for the savings calculation, is considered to be the best approach to evaluating the energy savings of building retrofits ( ASHRAE Guideline 14). However, when applied to a large portfolio savings analysis with substantial multi-year data, the change-point model does not fit the data well in some cases. The study thus aims to improve the accuracy of the changepoint model by: 1) using more advanced non-linear models, 2) incorporating additional input features, and 3) increasing the time resolution of input variables. We found that random forest …

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Use Of Calibrated Building Simulation To Investigate Comfort Conditions In A Healthcare Facility, Luca Zaniboni, Giovanni Pernigotto, Matthias Schuß, Kristina Kiesel, Andrea Gasparella, Ardeshir Mahdavi Sep 2018

Use Of Calibrated Building Simulation To Investigate Comfort Conditions In A Healthcare Facility, Luca Zaniboni, Giovanni Pernigotto, Matthias Schuß, Kristina Kiesel, Andrea Gasparella, Ardeshir Mahdavi

International Building Physics Conference 2018

Design activity regarding healthcare buildings must not only address the energy efficiency aspects but also account for the indoor thermal comfort conditions. Indeed, the occupants of this category of buildings are affected by different kinds of health issues. Thus, particular efforts are required in order to ensure conditions adequate for therapies and medical treatments. Simulation can be a helpful tool in designing new buildings, particularly in case of complex clinics and hospitals. When analyzing existing facilities, a proper calibration is a necessary step to reduce discrepancies between simulated and measured performance. This improves the reliability of the model itself and …

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Inter-Activehouse: Users-Driven Building Performances For Nearly Zero Energy Buildings In Mediterranean Climates, Arianna Brambilla, Federica Brunone, Alberto Sangiorgio, Marco Imperadori Sep 2018

Inter-Activehouse: Users-Driven Building Performances For Nearly Zero Energy Buildings In Mediterranean Climates, Arianna Brambilla, Federica Brunone, Alberto Sangiorgio, Marco Imperadori

International Building Physics Conference 2018

Building simulations rely on fixed assumptions and mathematical models to describe a specific building scenario, overlooking the building occupants’ component. Almost 40% of in-home energy use is due occupants interacts with the building systems. The goal of this paper is to understand the magnitude of the performance gap when applied to two case studies in a Mediterranean climate. A set of scenarios are simulated assuming both a typical building usage and possible variations given by the users’ interactions with shading, ventilation and cooling systems. Results show that the magnitude of the effects with a negative impact is bigger if compared …

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Assessing The Performance Of Photocatalytic Oxidation Of Volatile Organic Compounds In Three Different Scaled Set-Ups, Zahra Shayegan, Chang-Seo Lee, Ali Bahloul, Fariborz Haghighat Sep 2018

Assessing The Performance Of Photocatalytic Oxidation Of Volatile Organic Compounds In Three Different Scaled Set-Ups, Zahra Shayegan, Chang-Seo Lee, Ali Bahloul, Fariborz Haghighat

International Building Physics Conference 2018

Volatile organic compounds (VOCs) are considered a major group of indoor air contaminants with several proven adverse health effects. Ultraviolet photocatalytic oxidation process (UVPCO) is a promising technology for the removal of VOC contaminants in indoor air environments. In addition, adequate efficiency of PCO has been proven in laboratory conditions. However, when PCO is scaled up and applied in real conditions, there are some limitations that need to be addressed. Several factors are involved in the efficiency of the PCO process such as humidity, flow rate (residence time), inlet of contaminant concentration, light source, etc. To the best of our …

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Fate Of Particles Released By A Puff–Dispersion With Different Air Distributions, Shichao Liu, Atila Novoselac Sep 2018

Fate Of Particles Released By A Puff–Dispersion With Different Air Distributions, Shichao Liu, Atila Novoselac

International Building Physics Conference 2018

Well-mixed assumption normally has flaws in the space with continuous-releasing particle sources. For transient point or puff sources, however, particle concentration might vary differently among locations during emission periods and afterwards. This study measures whether and how rapidly ventilation systems can distribute particles emitted from puff-like sources in an indoor space. The impact of ventilation pattern (over-head mixing ventilation and displacement ventilation), particle size (0.77, 2.5 and 7 μm) and source location are also examined. The results show that particles with sizes of 0.77 μm and 2.5 μm can be distributed uniformly by both mixing ventilation and displace ventilation shortly …

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New Microclimate Monitoring Method And Data Process For Investigating Environmental Conditions In Complex Urban Contexts, Ilaria Pigliautile, Veronica Lucia Castaldo, Anna Laura Pisello Sep 2018

New Microclimate Monitoring Method And Data Process For Investigating Environmental Conditions In Complex Urban Contexts, Ilaria Pigliautile, Veronica Lucia Castaldo, Anna Laura Pisello

International Building Physics Conference 2018

The rapid urbanization of the last century coupled with local climate change imputable to anthropogenic actions triggered a huge research effort aimed at investigating urban microclimate. Typically, cities present a variety of microclimates due to the internal variation of their landscapes in terms of morphology, surfaces properties, presence of greenery, etc. Location-specific microclimate conditions affect both (i) building energy needs and (ii) citizens’ quality of life. For these reasons, a small-scale analysis from the citizen perspective with high-time-resolution environmental data is required. Recent studies tried to reach that level of precision by using remote sensing, movable observational transects or dense …

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Energy Flexibility Of Building Cluster – Part I: Occupancy Modelling, Rongling Li, Andong Wang, Carsten Rode, Shi You Sep 2018

Energy Flexibility Of Building Cluster – Part I: Occupancy Modelling, Rongling Li, Andong Wang, Carsten Rode, Shi You

International Building Physics Conference 2018

With the growing application of renewable energy, the stability of power systems can be seriously affected due to the fluctuations in the instantaneous generated power. As one of the potential solutions for this upcoming challenge, energy flexibility of buildings has received attention for research and technology development. Demand response and energy flexibility should be implemented at a large scale to have the accumulated energy flexibility to a magnitude, which can be meaningful for energy sectors. Studies have shown that the energy flexibility of a building is greatly influenced by both building physical characteristics and occupancy pattern of residents. To the …

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Radon Levels In Rented Accommodation, Torben Valdbjørn Rasmussen Sep 2018

Radon Levels In Rented Accommodation, Torben Valdbjørn Rasmussen

International Building Physics Conference 2018

Indoor radon levels were measured in 221 homes located in 53 buildings, including 28 multioccupant houses and 25 single-family terraced houses. The homes consisted of rented accommodation located in buildings recorded as being constructed before 2010 and after the year 1850. In addition, the radon level was measured in the basement in 9 of the buildings. The mean year value of the indoor radon level was 30.7 (1–250) Bq/m3. The indoor radon level exceeded 100 Bq/m3 in 5.9% of the homes, all located in single-family terraced houses. The variable single-family terraced houses explained 5.9% of the variation in indoor radon …

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Improving The Representation Of Convective Heat Transfer In An Urban Canopy Model, Qi Li, Jiachuan Yang, Zhi-Hua Wang, Elie Bou-Zeid Sep 2018

Improving The Representation Of Convective Heat Transfer In An Urban Canopy Model, Qi Li, Jiachuan Yang, Zhi-Hua Wang, Elie Bou-Zeid

International Building Physics Conference 2018

The urban street canyon has been widely recognized as a basic surface unit in urban micrometeorological studies. Urban canopy models (UCMs), which quantify the exchange of energy and momentum between the urban surface and the overlying atmosphere, often adopt this type of street canyon representation as the fundamental surface element. Since UCMs can be coupled to regional-scale weather and climate models such as the Weather Forecast and Research Model (WRF), parametrizations of the surface momentum and scalar fluxes in UCM are of paramount importance. However, many current single-layer UCMs rely on empirical relations that were obtained over 80 years ago …

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Streamlined Cfd Simulation Framework To Generate Wind-Pressure Coefficients On Building Facades For Airflow Network Simulations, Timur Dogan, Patrick Kastner Sep 2018

Streamlined Cfd Simulation Framework To Generate Wind-Pressure Coefficients On Building Facades For Airflow Network Simulations, Timur Dogan, Patrick Kastner

International Building Physics Conference 2018

Energy modeling packages such as EnergyPlus and TRNSYS come with capable airflow network solvers for natural ventilation evaluation in multi-zone building energy models. These approaches rely on pressure coefficient arrays of different wind directions based on simple boxshaped buildings without contextual obstructions. For specific sites, however, further attention is needed to avoid geometric oversimplification. In this study, we present an automated and easy-to-use simulation workflow for exterior airflow simulation based on OpenFOAM to generate pressure coefficient arrays for arbitrary building shapes and contextual situations. The workflow is compared to other methods commonly used to obtain pressure coefficients for natural ventilation …

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Unsteady-State Exergy Analysis On Two Types Of Building Envelopes Under Time-Varying Boundary Condition, Wonjun Choi, Ryozo Ooka, Masanori Shukuya Sep 2018

Unsteady-State Exergy Analysis On Two Types Of Building Envelopes Under Time-Varying Boundary Condition, Wonjun Choi, Ryozo Ooka, Masanori Shukuya

International Building Physics Conference 2018

In the built environment, the thermal exergy behavior is very sensitive to the change of environmental temperature, because the temperature difference between the reservoir and a system of interest is small. Moreover, the transient characteristics become very important for the building envelope, which is primarily affected by the environmental temperature changes and has a relatively large heat capacity. Most of the exergy analyses have been performed under steady-state assumption. However, it may miss some important details of the transient process. Thus, when the transient transfer process becomes important, the unsteady-state exergy analysis should be conducted. In this study, we propose …

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