Physical Sciences and Mathematics Commons^™

Pcm-To-Air Heat Exchangers For Free Cooling Applications, Mohamed Dardir, Mohamed El Mankibi, Fariborz Haghighat

International Building Physics Conference 2018

Applications of PCM-to-air heat exchangers (PAHXs) were discussed in literature for free cooling application due to their latent thermal storage abilities. This paper aims to justify the generalization of a numerical model of PAHX and to compare the thermal performance of two different configurations of PAHX system. A generalized numerical model is developed and validated based on general apparent heat capacity method. The validation results show good agreement of the generalized approach in terms of averaged error with the experimental data. Model potential and limitations are discussed, and further recommendations are proposed to improve model accuracy. The paper ensures the …

Building Information Modeling (Bim) Implementation For Sustainability Analysis: A Mega Airport Project Case Study, Basak Keskin, Baris Salman

International Building Physics Conference 2018

It has been generally perceived that decision-making processes for implementing sustainable solutions to building elements should be in design and pre-construction phases. This perception hinders the transformation of current non-sustainable buildings into sustainable ones. It has been realized that retrofitting existing buildings can be more beneficial in terms of time and cost compared to new construction. This study aims to show that implementation of Building Information Modeling (BIM) for energy analysis improves the retrofit planning process. This study explains that in practice, BIM tools provide significant opportunities for creation of Building Energy Modeling (BEM); and the outputs of BEM analysis …

Chemical Analysis Of Precipitation And Stormwater Runoff From A Large Green Roof, Kimberly Fitzgerald, Alexander Johnson, Cliff I. Davidson

International Building Physics Conference 2018

The growth medium of a green roof is likely to affect the chemistry of the rainwater passing through it, which may impact the receiving waters. Currently only limited data exist on the changes in rain chemistry caused by green roofs. The objectives of this project are to determine the differences in concentration of several contaminants in rain and in runoff from a green roof in downtown Syracuse, NY, and to explore reasons for the observed differences. A few samples were collected in 2014 and 2016, but most of the data are from 2017. Collection of precipitation uses funnels, while collection …

Computational Evaluation Of The Thermal Performance Of Underground Bunkers: The Case Of Albania, Rudina Breçani, Sokol Dervishi

International Building Physics Conference 2018

The present paper studies the thermal and energy performance and potential adaptive reuse of the lost underground bunkers of Kukës, Albania. The approach is exemplified using a 150-m long cross-section of the underground network selected for the parametric computational simulations. Data regarding local climate, design typology, and building materials is used to generate a finite-element simulation model of the underground tunnels. Different scenarios including insulation of the outer walls, occupancy patterns, and ventilation regimes are tested. The results show that indoor air temperature ranges from 15-18°C during winter and 23-28°C during summer. During January, the temperatures are higher by 3-5 …

Criteria For Identifying Failure Optimization Algorithms In Building Energy Optimization And Case Studies, Binghui Si, Xing Shi

International Building Physics Conference 2018

Optimization algorithms plays a vital role in the Building Energy Optimization (BEO) technique. Although many algorithms are currently used in BEO, it is difficult to find an algorithm that performs well for all optimization problems. Some algorithms may fail in some cases. This study specifically focuses on failure algorithms in BEO and the possible causes. Several criteria are proposed for identifying failure algorithms. Four optimization problems base d on the DOE small and large office buildings are developed. Three commonly used algorithms in BEO, namely, Pattern Search (PS ) algorithm, Genetic Algorithm (GA ) and Particle Swarm Optimization (PSO) algorithm, …

Effects Of Gaseous Pollution And Thermal Conditions On The Corrosion Rates Of Copper And Silver In Data Centre Environment: A Literature Review, Rui Zhang, Roger Schmidt, Jeremy Gilbert, Jensen Zhang

International Building Physics Conference 2018

The objectives of the present review are to: 1) summarize the existing knowledge on the mechanisms of the corrosion, identify and analyze the major factors affecting the corrosion of copper and silver; 2) compare various measurement techniques for the study of atmospheric corrosion and models of corrosion; 3) identify knowledge gaps for atmospheric corrosion; 4) recommend “realistic worst case” pollution levels for laboratory testing of humidity and temperature effects on corrosion and assessment of datacom equipment reliability in data centers. This review focuses on the five pollutants: SO2, NO2, H2S, O3 and Cl2. Results of the review include: the pollution …

Elaboration Of The Decision Space For An Optimization Of Building Retrofit, Yannis Merlet, Simon Rouchier, Arnaud Jay, Monika Woloszyn

International Building Physics Conference 2018

Multiobjective optimization is widely used in building physics but it has to face construction and regulation constraints to elaborate feasible solutions. This paper investigate how to integrate constraints in genetic optimization carried out with NSGA2 algorithm: it studies the implementation of constraints in the decision space and its impact on convergence speed and diversity in the optimization. The study was carried out on a 8 appartments building with three objective function to optimize: energy demand, comfort of the tenants and economic cost. As a result, convergence speed was improved and expert knowledge was included inside the decision space in a …

Experimental Investigation Of The Impact Of Pcm Containment On Indoor Temperature Variations, Iva Rešetar, Norbert Palz

International Building Physics Conference 2018

In view of growing concerns on climate change and temperature extremes, there is a need to explore novel methods that provide thermal comfort in architecture. Latent heat thermal energy storage with phase change materials (PCM) has been widely researched in last decades in the field of energy technology and proved beneficial for reduction and shifting of the thermal loads and improving the overall thermal storage capacity of building components. Although a variety of PCM containments have been investigated for indoor cooling applications, the examples of exposed, design-oriented macro-encapsulations are rare. This paper presents a study of visible, suspended ceiling encapsulations …

Hygrothermal Performance Of Historic Massive Wall: When Is 2d Simulation Necessary?, Dario Bottino Leone, Marco Larcher, Alexandra Troi, John Grunewald

International Building Physics Conference 2018

Hygrothermal analysis of historical building envelopes is crucial in ensuring their durability and enhancing their performances. The use of hygrothermal dynamic simulation is the most effective approach to predict moisture related damages or risk of mould growth on ancient masonry envelopes. However, simulating the hygrothermal behaviour of a historic wall composed by stones or bricks and mortar joints, with a detailed two-dimensional (2D) model, is typically a complex and time-consuming process. For this reason, in numerical models, composite walls are often simplified with a one-dimensional (1D) layer, neglecting the mortar joints. An oversimplified numerical model could affect the evaluation of …

Innovative Composite Materials With Enhanced Acoustic, Thermal, And Optical Performance For Urban Pavements: Experimental Characterization, Verronica Lucia Castaldo, Claudia Fabiani, Anna Laura Pisello, Franco Cotana

International Building Physics Conference 2018

Over the last decades, the implementation of innovative multifunctional materials for urban surfaces has produced a variety of paving solutions characterized by self-cleaning, self-healing, electricity conductive, solar reflective, sound absorbent properties and so on. Therefore, a key challenge is nowadays represented by the need for combining multi-physics properties in a single material or system for flooring. The present work concerns the development of a new outdoor paving application with enhanced acoustic, thermal, and optical performance. To this aim, eleven concrete mix-designs were tested. The composites were characterized by different aggregate size, material and additives. The aggregates included in the composite …

Intrinsic Evaporative Cooling With Natural Ventilation And Shading For Adaptive Thermal Comfort In Tropical Buildings, Mae-Ling Lokko, Alexandra Rempel

International Building Physics Conference 2018

Hygroscopic materials, including earth- and plant-based materials used in tropical vernacular architecture, often sorb significant moisture from the atmosphere during humid nighttime hours; evaporation the following day then provides a pronounced cooling effect, particularly in semi-arid regions. While such intrinsic evaporative cooling is also active in wet-tropical climates, it cannot maintain indoor comfort, and vernacular structures are highly open to facilitate air movement. Recently, new hygroscopic materials have been developed from coconut agricultural wastes that show great potential for intrinsic evaporative cooling and indoor humidity control in contemporary tropical buildings. As expected, however, they must be combined with additional cooling …

Long Term Measurements And Ham Modelling Of An Interior Insulation Solution For An Office Building In Cold Climate, Paul Klõšeiko, Targo Kalamees

International Building Physics Conference 2018

Excessive mould damage was detected in an office building in Northern Europe and thus a renovation need was established. This paper studies a renovation solution using measurements and heat, air & moisture (HAM) modelling. Polyurethane (PUR) foam was used to fill the air gap in masonry while capillary active calcium silicate (CaSi) insulation was used on the interior surface at thermal bridges. During renovation works temperature and relative humidity (t&RH) and heat flux sensors were installed throughout the wall. Nearly 3 years of measurements are presented. Average thermal transmittance (U) of the wall was reduced around 3 times. While the …

New Technology Creates New Lightscape, Jianzhen Qiu, Shuoxian Wu

International Building Physics Conference 2018

Light is a key element of our world’s beauty. Chinese scholar Wu Shuoxian put forward the concept of “Lightscape”, and proposed its research as a parallel discipline of the “Soundscape”. As a special aspect of the visual-scape, lightscape can give us a comprehensive and multi-disciplinary perspective of living environment. Many traditional lightscape cases have always been remembered as the representations of specific regional cultures. This article presents several cases of modern lightscape created with new technologies and methods. Included in these cases are: outstanding lightscape and art installments created by artists using light as a key element and fulfilled with …

Preliminary Monitoring Results Of Ventilated Heavyweight Building Envelope From Recycled Aggregate, Marina Bagarić, Ivana Banjad Pečur, Bojan Milovanović

International Building Physics Conference 2018

Potential of recycled aggregate concrete (RAC) has already been acknowledged by many researchers, but the focus was primarily on its mechanical and durability properties at material level. If the focus is shifted to element and whole building level, then the question can be raised; how building envelopes made from RAC behave when exposed to real environment? The present paper describes an experimental set up to monitor hygrothermal behaviour of one three-storey family house built with prefabricated ventilated sandwich wall panels made from recycled concrete and recycled brick aggregate. This type of building envelope can be classified as a heavyweight envelope. …

Roof Windows For Passive Houses – What Can Be Improved?, Jan Tywoniak, Kamil Staněk, Vítězslav Calta

International Building Physics Conference 2018

In general, skylights and roof windows in pitched roofs ca n be described as the critical components of buildings concerning heat losses, risk of surface condensation, increased risk of overheating of rooms behind etc. This is very sensible task especially for passive house solutions. The paper informs about studies analyzing the importance of these relatively small areas in the building envelope and more detailed in pitched roof of a passive house. One of the key problems is the position of roof window within the pitched roof construction. Second part of the paper comments results of detailed analysis of thermal performance …

The Design, Construction And Commissioning Of A Small Scale Dynamic Calibrated Hot Box (Chb), Timothy P. O’Leary, Aidan Duffy

International Building Physics Conference 2018

Sustainable construction and in particular the sustainability of materials is a global issue with legislation on material properties and product performance at the forefront. In traditional constructed buildings however, it can be extremely challenging to get accurate data on performance. The variability of building materials design, manufacture and construction from different eras is substantial, even within local areas due to the vernacular nature of construction from these periods. Material properties testing can be expensive and is not always readily available when required and is therefore often ignored, particularly in the retrofitting of historic buildings. This can have major adverse effects …

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 …

Uncertainty In Building Energy Performance Characterization: Impact Of Gas Consumption Decomposition On Estimated Heat Loss Coefficient, Marieline Senave, Glenn Reynders, Behzad Sodagar, Dirk Saelens

International Building Physics Conference 2018

Characterization of building energy performance indicators such as the Heat Loss Coefficient (HLC) based on in-situ measurement data calls for thorough building physical insight, a well -designed measurement set-up to collect sufficient, qualitative data and adequate data analysis methods. On-board monitoring may be an alternative for dedicated experiments to perform the data collection task. This paper analyses the sensitivity of the end-result of the characterization, the H LC estimate, to flaws in the monitoring data set. More specifically, the impact of not installing submeters to disentangle the gas consumption for space heating and the production of domestic hot water is …

Ventilation Potential Assessments For Residential Building Arrangements Based On Exceedance Probability Analysis, Wei You, Lian Tang, Wowo Ding

International Building Physics Conference 2018

In this study, the building ventilation potentials were assessed at building group level. Exceedance probability analysis was applied to estimate the uncertainties associated with the influence of climate on wind environment. The criterion was proposed based on building facade pressures. Tw o typical residential building arrangements were investigated. Simulation results show that facade pressure based exceedance probability are efficient in assessing the natural ventilation potentials of building groups and building height variations are important for improving building natural ventilation potentials.

Layer-By-Layer Construction Strategies Towards Efficient Czts Solar Cells, Matthew J. Turnbull

Electronic Thesis and Dissertation Repository

Solar energy has very high potential for ensuring the world’s energy requirements for the long-term future. Earth-abundant materials like Cu₂ZnSnS₄ (CZTS) are especially desirable, with a non-toxic, low-cost nature, though the quaternary nature allows for a lot of crystal structure variability, and thus underwhelming performance. This Ph.D. thesis is devoted to deepening the understanding of the CZTS material formation, and the processes that can be used to control it, to construct a low-cost, high efficiency CZTS-based solar cell. The layer-by-layer approach presented within this thesis shows great potential for rectifying the problem. CZTS nanocrystal (NC) stoichiometric control …

Tangent Lines, Samuel Estep

The Kabod

In [1] Leibniz published the first treatment of the subject of calculus. An English translation can be found in [2]; he says that

to find a tangent is to draw a right line, which joins two points of the curve having an infinitely small difference, or the side of an infinite angled polygon produced, which is equivalent to the curve for us.

Today, according to [3],

a straight line is said to be a tangent line of a curve y = f(x) at a point x = c on the curve if the line passes through the point (c, …

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. …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Modeling And Model Calibration For Model Predictive Occupants Comfort Control In Buildings, Shiyu Yang, Man Pun Wan, Bing Feng Ng, Zhe Zhang, Adrian S. Lamano, Wanyu Chen

International Building Physics Conference 2018

Mathematical models are essential in Model-Predictive Control (MPC) for building automation and control (BAC) application, which must be precise and computationally efficient for realtime optimization and control. However, building models are of high complexity because of the nonlinearities of heat and mass transfer processes in buildings and their air-conditioning and mechanical ventilation (ACMV) systems. This paper proposes a method to develop an integrated linear model for indoor air temperature, humidity and Predicted Mean Vote (PMV) index suitable for fast real-time multiple objectives optimization. A linear dynamic model is developed using SIMSCAPE language based on the BCA SkyLab test bed facility …