bluuebunny/crossref_metadata_2025 huggingface dataset:
Kathakali face expression detection using deep learning techniques
Authors: Selvi C , Anvitha Y , Asritha C H , Sayannah P B
Published: December 2021

To develop a Deep Learning algorithm that detects the Kathakali face expression (or Navarasas) from a given image of a person who performs Kathakali. One of India’s major classical dance forms is Kathakali. It is a “story play” genre of art, but one distinguished by the traditional male-actor-dancers costumes, face masks and makeup they wear. In the Southern region of India, Kathakali is a Hindu performance art in Malayalam speaking. Most of the plays are epic scenes of Mahabharata and Ramayana. A lot of foreigners visiting India are inspired by this art form and have been curious about the culture. It is still used for entertainment as a part of tourism and temple rituals. An understanding of facial expressions are essential so as to enjoy the play. The scope of the paper is to identify the facial expressions of Kathakali to have a better understanding of the art play. In this paper, Machine Learning and Image Processing techniques are used to decode the expressions. Kathakali face expressions are nine types namely-Adbhutam (wonder), Hasyam (comic), Sringaram(love), Bheebatsam(repulsion), Bhayanakam(fear), Roudram(anger), Veeram(pride), Karunam(sympathy) and Shantham (peace). These Expressions are mapped to real world human emotions for better classification through face detection and extraction to achieve the same. Similarly a lot of research in terms of Preprocessing and Classification is done to achieve the maximum accuracy. Using CNN algorithm 90% of the accuracy was achieved. In order to conserve the pixel distribution and as no preprocessing was used for better object recognition and analysis Fuzzy algorithm is taken into consideration. Using this preprocessing technique 93% accuracy was achieved.
Prediction of EV arrivals at Battery Swapping Station using Hybrid Neural Network models
Authors: Suri Manikanta , Raj Neha , Sireesha K
Published: December 2021

There is an enormous increase in demand for Electric Vehicles (EV) in the present era, as they are environment-friendly when compared to conventional vehicles. Battery Swapping Stations (BSS) are gaining a lot of attention from the EV sector as it is like the gasoline stations. Forecasting of EV arrivals at BSS helps in optimally scheduling the depleted batteries to different charging piles without affecting the State of Health of the battery. Back Propagation Neural Network (BPNN) is widely used in the prediction of real-time data. Training of BPNN using metaheuristic algorithms such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) helps to overcome the local optima problem in BPNN. Thus, in the present work forecasting on the EV arrivals is carried out using GA-BPNN and PSO-BPNN hybrid models. Finally, a comparative study is carried out among BPNN, GA-BPNN, and PSO-BPNN models using the performance metrics such as Mean Square Error (MSE), Mean Absolute Error (MAE) and Pearson Correlation Coefficient (PCC). From the results, it was obtained that GA-BPNN model is preferred in forecasting the EV arrivals at BSS as the model has less overfitting. The hybrid models have been simulated in MATLAB/Simulink software.
Improved Hybrid Salp swarm and Sine-cosine Optimization based MPPT Control for PV Systems Under Partial Shading Conditions
Authors: Mishra Chandrakanta , Tiwari Sheela
Published: December 2021

A novel improved meta heuristic method, Hybrid salp swarm using sine cosine algorithm (Hybrid SS-SC) for maximum power point tracking (MPPT) under partial shading condition is proposed in this paper. The proposed algorithm envisages finding the best GMPP. The simulation studies clearly demonstrate that the method compares favourably with the conventional P&O method as well as with some other nature inspired algorithms in tracking GMPP in less time.
Investigation of 1-Hexanol Diesel Blends on Performance, Combustion and Emission Characteristics of a Diesel Engine
Authors: Singh Ashish Kumar , Khan Mohd.Mohsin , Pali Harveer Singh
Published: December 2021

The most potential long-term and renewable substitute of mineral diesel are biofuels. The growth and degradation of energy resources have an enormous influence on the long-term viability of the human community. Alcohols are gaining prominence in the current renewable energy scenario due to their ease of manufacturing and fuel characteristics. In this investigation, hexanol-diesel blend ratios (up to 20% v/v) is taken into account for this investigation in a single cylinder, water cooled, unmodified 4-stroke DI diesel engine. The increase in 1-hexanol volume content correlates to an improvement in combustion thereby promoting brake thermal efficiency. The greater concentration of oxygen in 1-hexanol reduces emission viz. HC and CO and increases value of NOx. Current investigation recommends a feasible option to substitute ULSD for the capabilities of 1-hexanol.
Application of Pyrolysis and Hydrothermal Liquefaction Process to Convert Bio-Fuel from Biomass
Authors: Kumar Amit , Pali Harveer Singh , Kumar Manoj
Published: December 2021

Rapid increase in demand of fuels creates the challenge for scientific community. The fossil fuel resources are declining day by day. So, biomass derived fuel starts to feel an exquisite alternative option, by reason of it develop from residual cooking oil, animal fats, or vegetable oils, etc. In present work biomass is converted into bio-fuel by the process of pyrolysis and hydrothermal liquefaction. But if it is compared with fossil fuel some undesirable properties have been found such like high oxygen content high water content, high corrosiveness and high viscosity etc. Directly biofuels cannot be used in IC engine due to their unwanted content in the fuel. Therefore upgrading of bio-fuel is needed to improve its properties for liquid fuels by the pre-treatment process of biomass. The purpose of biomass pre-treatment is the degradation of cellulose phibrils, lowering their crystallization and polymerization levels, hemicelluloses separation and degradation of cellulose. However application to this bio-fuel have been needed to enhance its properties for CI engine fuel using blending for direct use in engine application.
Study of hygroscopic behaviour of spruce during adsorption and desorption
Authors: Zhou X , Desmarais G , Mannes D , Derome D , Carmeliet J
Published: December 2021

Sorption of water vapour in hygroscopic porous materials is associated with latent heat release and absorption. This phenomenon should be taken into account to achieve a better understanding of the coupled transfer of vapour and heat in hygroscopic porous materials. In this paper, water vapour adsorption and desorption in the longitudinal direction of spruce samples are studied. Neutron radiography is used to measure changes in moisture content and wireless thermocouples are used to measure temperature changes. During the adsorption and desorption experiments, large changes in moisture content and temperature are observed. A hygrothermal model is developed to simulate vapour and heat transfer during adsorption and desorption experiments. Generally, the numerical model predicts well the measured moisture and temperature changes. The large moisture change is due to the low vapour resistance factor in the longitudinal direction of the spruce samples. The latent heat associated with vapour adsorption is the cause of the large temperature changes. It was found that vapour permeability affects both vapour and heat transfer, while thermal conductivity only affects heat transfer.
Recent progress on hygroscopic materials for indoor moisture buffering
Authors: Zhang Xu , Qin Menghao , Zu Kan
Published: December 2021

Once in contact with the indoor air, hygroscopic materials can moderate the indoor humidity fluctuation by adsorbing or releasing water vapour, and then improve the moisture regulation and thermal management of buildings. It is desirable to explore the characterized properties of these materials about moisture buffering behaviour. In this regard, we review various hygroscopic materials used for the built environment control. The hygrothermal properties of hygroscopic materials often can be characterized by some parameters, such as water vapour adsorption/desorption capacity, water vapour adsorption/desorption rate, water vapour diffusion coefficient, and so on. To provide an insight on the existing research on humidity control materials, different research studies and the recent progress on humidity control materials have been summarized. The materials include traditional and conventional building materials, some natural materials, and novel humidity control materials. Besides, the relevant parameters are considered as well as the improvement suggestions to enhance the application of humidity control materials in building environments. Finally, new multifunctional materials and intelligent moisture control materials together with the corresponding systems are collated to summarize the latest research trends. The overview of the application of hygroscopic materials can provide current and future researchers guidelines for the science-oriented design of moisture control systems for new energy-efficient buildings.
Water vapour permeability of wood – remarks on cup method procedure and measured data of spruce wood
Authors: Richter Jan , Staněk Kamil
Published: December 2021

Although the water vapour permeability of wood has been determined many times, there can be found a wide spread of values even related to only one wood specie and its single anatomical direction. This spread can possibly be attributed to the measurement method itself, since the cup method often shows high inter-laboratory error. However, even if the measurement and evaluation processes are well performed and under control, there were found several factors that can still highly affect the resulting value – up to ca. 70 %. These factors are neither mentioned in standards, nor were found in other sources. This paper theoretically describes those factors and their possible impact to the final value of water vapour permeability. Paper also presents one particular measurement scheme and obtained data from four cup tests performed on spruce wood in transverse direction.
Moisture-induced deformations of wood and shape memory
Authors: Zhang Chi , Chen Mingyang , Derome Dominique , Carmeliet Jan
Published: December 2021

Wood is known to swell substantially during moisture adsorption and shrink during desorption. These deformations may lead to wood damage in the form of cracking and disjoining of wooden components in e.g. floor or windows. Two swelling mechanisms may be distinguished: reversible swelling/shrinkage and moisture-induced shape memory effect. In the latter, wood is deformed in the wet state and afterward dried under maintained deformation, in order that wood retains its deformed shape even after the removal of the mechanical loading, called fixation. When wood is wetted again, it loses its fixation, partially regains its original shape, called recovery. These two mechanisms have their origin at the nanoscale and are modelled here using atomistic simulation and after upscaled to continuum level allowing finite element modelling. Hysteretic sorption and swelling are explained at nanoscale by the opening and closing of sorption sites in ad-and desorption, where in desorption water molecules preferentially remained bonded at sorption sites. The moisture-induced shape memory is explained by the moisture-induced activation of the interfaces between the reinforcing crystalline cellulose fibres and its matrix at nanoscale, referred to as a molecular switch. Our work aims to highlight that the understanding of sorption-induced reversible deformation and moisture-induced shape memory may play an important role in wood engineering and in building physics applications.
Effects of different light wavelengths on mold growth in tomb
Authors: Zhou X H , Xie H R , Pei Y , Liu W J , Hokoi S , Li Y H
Published: December 2021

The Second Mausoleum of the Southern Tang Dynasty have a history of more than 1,000 years in China. Since its opening in 1984, the building materials and murals inside the tomb have been severely damaged by mold. Field investigation found that the mold growth on the wall illuminated by the light in the tomb was more flourishing than that in the area without the light. Lighting in the tomb is inevitable for the exhibition. Therefore, the purpose of this study is to clarify the effects of different light wavelengths on the growth of mold in the tomb, and provide the theoretical basis for the lighting design in the tomb chamber. This study is divided into two parts, including in-situ experiment and laboratory experiment. In the in-situ experiment, four kinds of light wavelengths (white, red, blue, and green) were set in the tomb chamber to observe the difference of mold growth on the mural wall. The concentration of phototrophs propagules on different auricular walls was estimated in the laboratory.

The results showed that different light sources had different effects on microbial community composition in the tomb site and the red light had better inhibition effect on fungi and actinobacteria.
Impact on a CLT structure concerning moisture and mould growth using weather protection
Authors: Svensson Tengberg C , Bolmsvik Å
Published: December 2021

Timber buildings, including cross laminated timber (CLT), are gaining market shares globally, mainly due to anticipated environmental benefits, but a new technical solution also raises new questions. Durability is critical to obtain real sustainable constructions built for the future. There are field studies concerning hygrothermal conditions of timber structures, however, there is a lack of documented experiences combining hygrothermal conditions, mould growth potential and weather protection during construction using CLT. The use of full weather protection is being debated in the building industry as well as in the research community, due to lack of knowledge of the combined effects. How does weather protection during the construction affect hygrothermal conditions and risk of mould growth in a CLT structure? A case study using a weather protected six-storey CLT building was performed. The hygrothermal conditions – indoors and outdoors – were monitored during construction and samples from CLT were analysed with respect to mould. The results were analysed together with simulations of mould growth using actual hygrothermal conditions. Theoretical conclusions show the weather protection gives significantly improved conditions resulting in lower potential of mould growth compared to outdoor conditions. The results also show lessons to be learned concerning planning of the construction site.
Moisture safety in ventilated cathedral roofs
Authors: Månhardt G , Odén G , Stockhaus M , Wallentén P
Published: December 2021

Cathedral roofs are commonly used when constructing small houses in Sweden. In contrast to roof constructions with a cold attic, where frequent moisture damage has been noted, the cathedral roof is difficult to access for inspection. Furthermore, Swedish building regulations sets high demands regarding moisture safety, although there are no clear guidelines for their compliance. Hence, designing a cathedral roof must be done with great care. Previous studies investigating moisture safety in cathedral roofs, applies a constant air exchange in the ventilated air cavity. In this study a cathedral roof, ventilated from eave to eave, was analysed by examining the relevance of considering the variation in cavity air flow when conducting coupled heat and moisture calculations. The varied cavity air flow was calculated in an air flow model, considering wind and thermal buoyancy as driving forces. The accuracy of moisture safety assessments using the MRD model via hygrothermal calculations in WUFI Pro were also studied. Comparing moisture calculations with measurements showed high similarity when using a model with constant cavity air flow, and even higher resemblance when using a model with varied air flow. When actual conditions are sought, the study indicated that pinpointing important parameters, such as initial moisture content and moisture related material properties, would further increase precision in moisture calculations.
The impact of using Closed Cavity Façades (CCF) on buildings’ thermal and visual performance
Authors: Michael M , Overend M
Published: December 2021

Glazing is a critical buildings element as it is the most vulnerable envelope part to heat gain and heat loss accounting for around 50% of a building’s energy consumption. However, conventional glazing technologies have relatively low-performance characteristics which cause significant heat losses during winter and undesired heat gain in summer. In this regard, this study investigates the thermal and visual performance of various design configurations of a novel glazing technology, named Closed Cavity Façade (CCF), in comparison with traditional glazing technologies. Several CCF configurations were examined using Energy Plus and IDA ICE and compared to the baseline Double Glazing Unit (DGU) (traditional or thermochromic). MATELab, an office-like test facility at the University of Cambridge was used as the model for the simulations, which was beforehand experimentally validated. The results showed extensive benefits of CCFs compared to DGU systems, in terms of thermal performance and comfort. A 22-41% or 21-37% decrease in annual total energy consumption, compared to traditional DGU or thermochromic respectively, are identified along with a positive effect on thermal comfort with a significant reduction in radiant discomfort. Further investigation showed that glass coatings and solar shading device’s characteristics play an important role in achieving further performance improvements.
Performance analysis of the MICRO-V (Multifunctional, Integrated, Climate-responsive, Opaque, and Ventilated) façade with different ventilation modes
Authors: Soudian Shahrzad SS , Berardi Umberto UB
Published: December 2021

Climate-responsive facades (CRFs) are a potential solution to respond to transient energy exchanges in buildings to control and enhance the indoor environmental quality (IEQ). In addition to space heating and cooling, adequate ventilation within a thermally comfortable range is critical in new and retrofit constructions, particularly as current high-performance facades maximize airtightness. In this study, an opaque multifunctional CRF (MICRO-V) was investigated to regulate the flow of heat and air into buildings with daily and seasonal responses. This façade is made of phase change materials (PCMs), an adjustable insulation system, and an embedded ventilation unit to provide conditioned fresh air. The effect of different ventilation modes (balanced, only-exhaust, only-supply) on the overall thermal performance of the façade was studied. A CFD simulation study in the context of Toronto, Canada, in the cooling season was performed. The study showed a correlation between increased airspeed and overall heat recovery in the façade, with an average of 75-80% heat recovery between the indoor exhaust air and fresh supply air. The results showed how the façade’s operational modes could be adjusted based on the outdoor climate conditions. MICRO-V is a decentralized façade system with simultaneous air supply and exhaust, the findings showed the interconnected behaviour of the components in the façade and how it can provide conditioned fresh air.
Calibration of DSF model for real-time control
Authors: Gennaro G. , Favoino F. , Goia F. , Michele G. De , Perino M.
Published: December 2021

Double Skin Façades are complex fenestration systems capable to control solar heat gain and ventilation in buildings. Due to the high flexibility of such innovative components, having energy models able to replicate the thermal behaviour of the Double Skin Facades is of utmost importance for their optimal control and integration with building automation strategies. In this context, a numerical model has been developed and validate within the experimental data. The methodological steps are presented in this work and in the last section, the potential applications of the model are discussed.
Sensor specifications for in-situ measurement of the temperature distribution inside the wall material for evaluating thermal performance of residential buildings
Authors: Nagai T , Eto J
Published: December 2021

It is important to measure and ensure the thermal insulation performance of newly built or existing residential buildings to promote energy-efficient and comfortable housing throughout society. Among various in-situ measurement methods for this purpose, this study focuses on the probe insertion method, in which a borescope and a temperature sensor are inserted through a tiny hole drilled in the interior side of the wall to visually inspect and measure the temperature distribution inside the wall. In this method, the temperature sensor itself can act as a thermal bridge, which causes a deviation from the original temperature distribution inside the insulation material. In this paper, based on physical considerations and heat conduction simulation, we introduce two dominant dimensionless numbers that determine the temperature deviation: the Biot number and the newly defined Nc
value. In addition, we draw schematic charts to find the temperature deviation from the introduced dimensionless numbers, and suggest a procedure to determine the required specifications of a temperature sensor that can accurately measure the temperature distribution.
Hygrothermal performance assessment of split insulated cork wall assemblies under various moisture load conditions
Authors: Ghazaryan T , Tariku F
Published: December 2021

Every year along with the implementation of energy-saving, energy conservation and other green energy initiatives the demand for effective, but sustainable, renewable insulation materials in the construction industry increases. It is worth mentioning that the selection of insulation materials nowadays is not limited to its cost and technical characteristics only, but health-related aspects and carbon footprint are also taken into consideration. However, there are not many insulation materials that have competitive technical characteristics, are sustainable, renewable and do not pose risk for health. Cork and cork-based materials like insulation cork boards (ICB) are of these types of materials which have unusual combination of material properties, have low to negative carbon footprint and have low to almost zero negative impact on the ecology and human health during the whole life cycle and later on. That is why with the increasing demand for sustainable, renewable and ecological materials the interest toward cork in North America is expected to increase. However, there are not so many researches performed on lightweight wall assemblies common in North America with cork insulation applications. In this paper, the hygrothermal performance of natural cork insulation used in split wall assemblies is compared against similar, commonly used mineral wool and expanded polystyrene (EPS) wall assemblies for three different Canadian climates, using WUFI hygrothermal analysis computer simulation tool. The relative performance of seven wall assemblies, with various combinations of insulation type and vapor control strategies, exposed to different moisture loads including elevated indoor humidity, air leakage and rain penetration are presented. The simulation results suggest that, in general, assemblies with cork have a slight advantage in performance against the EPS assemblies, especially when the amount of moisture affecting the assemblies is high. In most cases, assemblies with mineral wool perform better than that of with cork and EPS insulations.
Hygrothermal simulation and risk evaluation - The impact of discretization on numerical results and performance
Authors: Sarkany Andreas , Bednar Thomas
Published: December 2021

Regulations for modelling when deducting thermal simulations are represented in the standards [1]. However, the level of model detail regarding discretization in hygrothermal simulations and especially for evaluating the mould risk on surfaces of organic vapour barriers is almost never discussed. The presented approach shows that the chosen discretization of the simulation model is one of the most influencing factors for the risk analysis of surfaces of very fine layers, such as paper vapour barriers, in walls with interior insulation via hygrothermal simulations. To reduce the computational performance issues caused by very fine finite volume meshes [2], the hygrothermal properties of the connecting surfaces of the finite volumes can be calculated instead. For the risk analysis the VTT-Model was implemented in the hygrothermal simulation program HAM4D_VIE, followed by a comparison of the effect of discretization on the results of the surfaces of the vapour barrier. The results of the comparison are discussed with regard to numerical results and their qualitative impact on computational performance. The presented numerical model will be proposed as an alternative for risk analysis on surfaces of vapour barriers, where mould growth would either stay undetected or the necessary discretization with elements comes at the cost of computational performance.
Heat and Moisture Modelling of Vacuum Insulated Retrofits with Experimental Validation
Authors: Conley B , Cruickshank C A , Baldwin C
Published: December 2021

Vacuum insulation panels (VIPs) offer 8-10 times the thermal resistance of fiberglass insulation and would fit the need for a low conductivity exterior insulation. A composite insulation panel using VIPs encased in rigid foam was developed, built, and tested. Two different sizes of VIPs were used for that stage of the project, and after monitoring and evaluation, they showed contrasting results. A simulation study was performed to find the optimal VIP solution that maximized the effective thermal conductivity and minimized the mould growth potential. In total, 5 wall assemblies with VIPs used as the exterior insulation were simulated using WUFI and WUFI2D. The simulations showed that the humidity levels at the inside face of the OSB inboard of the VIPs decreased when 200 mm by 300 mm VIPs were used, but they did not reach the thermal performance thresholds of R5.28 m2K/W. The hygrothermal analysis showed that under similar conditions, a VIP insulated wall assembly would have a lower relative humidity at the sheathing surface compared to EPS and XPS. The one-and two-dimensional simulations were compared and found that WUFI Pro was capable to evaluate a VIP-insulated wall assembly.
Process induced building defects in Norway – development and climate risks
Authors: Bunkholt N S , Gullbrekken L , Time B , Kvande T
Published: December 2021

The SINTEF building defects archive is an important source to knowledge on building defects in Norway. This study presents a review of defects investigated by SINTEF in the period 2017–2020, including 175 defect cases registered in 125 reports. The main goal is to understand the primary causes of process induced building defects today and which building elements may be considered as risk spots. The review shows that almost 3 of 4 defects is related to moisture, caused by sources as precipitation, condensation of humid indoor air or built-in moisture. Defects associated with the building envelope make up more than 70% of the cases, of which most defects are linked to exterior wall or roof constructions. The results from the present study have been compared to a review of defects reported in the archive during the period 1993–2002. The comparison reveals that the share of damages caused by precipitation is almost doubled, while the share of damages caused by humid air from the interior is approximately halved. The results imply that climate adaptation of buildings is important. As climate change causes more precipitation with higher intensities, the load on buildings increases and a larger focus on risk reduction and protection towards penetration of water from the outside is required.
Comparison of indoor moisture excess in three different terraced housing projects
Authors: Harreither C , Gengler J , Bednar T
Published: December 2021

In this study three neighbourhoods of terraced houses have been investigated. In 16 to 29 houses of each project, indoor temperature and indoor humidity have been measured, inhabitants have been interviewed and Blower-Door Tests have been performed. PSG is a project with 91 similar, very airtight detached houses. More than 29 of these houses have been investigated. TES is a low-rise high-density project with 46 single family houses built in 1974. The measuring results of 20 houses with very poor airtightness have been analysed. APW is a project with 26 terraced houses built in 2012, which have mechanical ventilation systems. From APW 16 houses have participated in the study. It will be illustrated that the airtight houses of PSG have the highest absolute indoor humidity, the TES houses with the poor airtightness have medium absolute indoor humidity and the APW with the mechanical ventilation systems have the lowest absolute indoor humidity. Box plots of the moisture excess in the diagram with the humidity classes from EN ISO 13788 [1] show that the boxes do not overlap.
CIB W040: International Surveys Considering Moisture Safety in Buildings During Design and Construction
Authors: Morishita-Steffen N , Laukkarinen A , Lewis T , Wolny S , Peuhkuri R , Vinha J , Bednar T
Published: December 2021

We conducted comparative surveys of design consultants in three countries to determine current knowledge and experienced moisture problems. The study is part of the CIB W040 research roadmap needs analyses for realigning research efforts with stakeholder requirements for moisture safety. Survey results show that a third of construction projects in the last five years were affected by moisture problems, even though practitioners applied multiple preventative measures at least some of the time. Water installations caused approximately 20 % of the moisture damage. In each country, preventing moisture damage was necessary; the means to address problems varied, with no one dominating solution. Design and construction guidelines were more helpful than the building code requirements. Information is available, but designers need dedicated time and budget for implementing better moisture safety. A quantitative goal is to increase the frequency of moisture safety measures while increasing the availability of tools. The usefulness of selected measures and instruments is strongly case-specific. Subtopic analysis such as causes of moisture damage due to leaky water installations needs more detailed investigation. Further research is needed building upon the online survey results to develop intelligent tools preventing moisture damage in the design, construction, and building occupancy phases.
Pore-scale investigation of dynamic effects on the moisture retention curve during spontaneous imbibition
Authors: Janetti Michele Bianchi , Janssen Hans
Published: December 2021

The moisture retention curve of porous materials is often assumed to be independent of the process dynamics, i.e., of the drying/wetting rate. Experimental outcomes and pore-scale simulations put this assumption into question though. It has been shown that dynamic effects can significantly affect the moisture retention curve, which presents different behaviours, depending on whether it is determined at transient or steady-state conditions. The cause of this phenomenon is addressed as “dynamic effects” in the literature. While dynamic effects of the drainage process have been widely studied, the data concerning spontaneous imbibition are still quite limited. We attempt at reducing this lack of knowledge by modelling spontaneous imbibition in an artificial material sample represented by a pore network model. In our model, the liquid flow is described via the Hagen-Poiseuille equation, while a percolation algorithm controls the dynamics of liquid-gas interfaces through the network junctions. A dynamic contact angle between liquid water and pore surface is considered, depending on the velocity of the meniscus. Dynamic states are determined by linking the local capillary pressure to the local moisture content in the artificial material sample subject to spontaneous imbibition. Our investigation demonstrates that dynamic effects due to contact angle variations may have a major impact on the imbibition process.
Capillary rising damp in Venetian context: state of the art and numerical simulation
Authors: Guolo E , Romagnoni P , Peron F
Published: December 2021

The fragility of Venice and its buildings are linked to the floods, observed since ancient times and emphasized in recent years: the periodic sea level rise, accompanied by rising damp, are the main causes of the alteration. In particular, the rising damp causes a series of complex diseases in the historic buildings, such as physical decay, chemical or biological, with loss of aesthetic and economic value. In addition, greater heat dispersion and reduced thermal comfort can also occur in interior spaces, with consequent risks for human health. This is a sign of “Sick Building Syndrome”. It is very important to develop models for assessing the vulnerability of assets and to manage sustainable plans related to maintenance processes and activities, satisfying the requirements of effectiveness and compatibility. Basing on numerical models performed with the WUFI 2D software, the paper analyses the different behavior of rising damp in relation to materials or masonry structures. In particular, the construction techniques and typical materials used in Venetian buildings were investigated, such as clay brick walls, lime plaster, Marmorino and Cocciopesto, adopted mainly to limit the capillary rise also caused by the phenomenon of “acqua alta”.
Influence of the disparities between lab and in-situ application on the penetration depth of a hydrophobic agent
Authors: Deckers D , Vereecken E , Roels S , Janssen H
Published: December 2021

Over the last few years, the application of a hydrophobic agent on a masonry wall has become popular due to its ability to reduce the amount of rain water absorption without changing the facade’s appearance. While the hygric properties of such hydrophobised materials are often investigated, research towards its penetration depth into materials is limited. Additionally, most existing research involves small samples made in a lab rather than masonry walls. This paper therefore focuses on two key differences between lab application and application on an actual masonry wall and their influence on the penetration depth of a hydrophobic agent. As the hydrophobic agent is applied differently on an in-situ masonry wall than on laboratory samples, the method of hydrophobisation is investigated first. It is shown that the penetration depth varies significantly for different methods of hydrophobisation as well as within single samples. Secondly, the existing research often targets separate brick or mortar samples rather than full-scale masonry walls. Therefore, several experimental methods are used to quantify the penetration depth in a masonry wall. From these experiments, it is shown that the penetration depth is not only variable throughout this wall, but within separate bricks or mortar joints as well.
Experimental investigation of a novel metal-organic framework (MOF) based humidity pump under high humidity conditions
Authors: Zu Kan , Qin Menghao
Published: December 2021

Latent heat load accounts for a significant proportion of air-conditioning energy consumption and particularly for specific environment in humid climates. Traditional vapor-compression refrigeration dehumidification faces the problem of refrigerant leakage, overcooling and complicated mechanical systems. Here, we report a novel humidity pump that uses semiconductor refrigeration and metal-organic frameworks (MOFs) as dehumidification method, which can efficiently transport moisture from a relatively ‘low-humidity’ space to a high-humidity one. The working principles of the humidity pump were introduced that the process air flows through the cold desiccant coated heat exchanger and then comes into direct contact with the MOF coatings to transfer heat and mass. The dehumidification performance of humidity pump was investigated in high humidity, and the dehumidification coefficient of performance (DCOP), dehumidification rate and moisture removal efficiency using MIL-100(Fe) coatings were calculated. The results indicated that the MOF humidity pump possesses excellent moisture transfer ability.
Characterising the effects of wind-driven rain on the thermophysical performance of cavity walls by means of a Bayesian framework
Authors: Gori V , Marincioni V , Altamirano-Medina H
Published: December 2021

Cavity wall is one of the most common construction types in temperate maritime climates, including the UK. However, water penetration may lead to damp within the structure, freeze-thaw damage at the outer surface and a reduction in thermal resistance. The magnitude of wetting effects on the energy performance of cavity walls is still unclear, with potentially significant implications for climate-change-mitigation strategies. This paper investigates the thermophysical performance of uninsulated and insulated cavity walls and its degradation as the element is wettened. Experiments were performed in a hygrothermal laboratory where two cavity-wall specimens (one of which coated with external waterproofing treatment) were tested under a high wind-driven rain exposure. Changes in the thermophysical performance between dry and wet conditions were evaluated through U-value testing and Bayesian inference. Substantial U-value increase was observed for wet uninsulated specimens (compared to dry conditions); conversely, closer U-value ranges were obtained when insulated with EPS grey beads. Moreover, latent-heat effects through the external masonry leaf of the untreated specimen were predicted by the Bayesian framework. Results suggest a negligible efficacy of waterproofing surface treatments as strategies for the reduction of heat transfer within the element, and possible effects of these agents on the evaporative and drying process.
Fundamental study on the thermodynamic non-equilibrium freezing probability prediction model taking into account the super cooling phenomena in porous material
Authors: Kishimoto Y
Published: December 2021

It is commonly considered that frost damage is caused by sudden freezing of supercooled water, which is a random phenomenon. Therefore, the aims of this study are to establish a prediction model for the probability of freezing until any lowest reached temperature, and to obtain the probability distribution function of the freezing point for the proposed analytical prediction model. First, theoretical prediction model for the probability of the instantaneous increment of ice content when lowest achieving temperature was known was derived based on these assumptions that building structure is an aggregation of small elements. Next, the freezing point measurement was carried out by using saturated mortar samples as the small element. As the results, it could be found that the first freezing due to supercooling occurred from -4 to -11 deg. C and the maximum probability was appeared at -7.5 deg. C. The average increment of ice content at every temperature closed to the 40 % volume of pore water until the thermodynamically-based freezing point. Moreover, the proposed method that can calculate the probability distributions of the instantaneous increment of ice content for any lowest achieving temperature from pore size distribution had good agreements with the measurement results.
Importance of Microscale Climate Simulations in City Scale Overheating Assessments
Authors: Shu C , Gaur A , Bartko M , Laouadi A , Ji L , Lacasse M , Wang L (L)
Published: December 2021

This study demonstrates the importance of high-resolution climate simulations when conducting city-scale outdoor heat wave alert and indoor overheating assessments. This is done by modelling urban climate of the Ottawa and Montreal cities at 1 km and 25 km, typical for regional climate modelling respectively, over the summer of 2018 when an extreme heat event caused around 100 deaths in these cities. It is shown that urban climate characteristics (higher temperatures, lower wind speeds, lower relative humidity in the urban core than surroundings) are better simulated at 1 km than at 25 km spatial resolution. Indoor conditions are simulated for an archetype model of a single detached house using EnergyPlus software for two locations within the cities: a) city center and b) airport location. It is shown that the simulated indoor air temperature in the building is highly correlated with the outdoor air temperature. Furthermore, it is found that the maximum indoor air temperature difference of the city center and the airport can be as high as 8°C in Montreal and 9°C in Ottawa. Such intra-urban differences in overheating in buildings will be ignored if microscale simulations are not performed, highlighting their importance for building overheating assessments in cities.
Mitigation measures for urban heat island and their impact on pedestrian thermal comfort
Authors: Kubilay A , Strebel D , Derome D , Carmeliet J
Published: December 2021

A multiscale coupled model is presented that allows for the detailed analysis of the local impact of urban heat island mitigation measures. The model uses coupled computational fluid dynamics (CFD) simulations with unsteady heat and moisture transport (HAM) in porous urban materials in order to take into account the dynamic heat and moisture storage in the built environment. A realistic case study is performed for a public urban square in the City of Zurich during heat wave conditions. The impacts of two different mitigation strategies, i.e. adding artificial wetting of pavements and adding vegetation, on pedestrian thermal comfort are evaluated and compared with the existing situation. The results show an improvement in thermal comfort in both conditions. The improvement resulting from the addition of trees is larger and lasts longer due to shadowing effects, even though a reduced ventilation and an increased relative humidity by trees have an adverse effect on the thermal comfort.
An automated workflow for informing urban greening based on photosynthetic radiation modelling
Authors: Kyropoulou M , Subramaniam S , Hoffmann S
Published: December 2021

The deliberate introduction of vegetation in urban environments, referred to as urban greening, is known to improve outdoor thermal comfort and mitigate the effects of Urban Heat Island in cities. Urban greening can be applied on ground level or elevated parks, roof tops, and building facades. The main parameters that affect plant growth are space, light, water, humidity, oxygen, carbon dioxide, mineral elements, and temperature. Of these parameters, light and temperature are the ones more unlikely to be supplemented in a non-controlled urban setting. This research presents the development of an automated workflow that facilitates design decisions on vegetation growth potential and vegetation species selection within their climatic and geometrical context. This novel scripting-based prototype uses hourly radiation results to extract location specifications, such as photoperiod, hardiness zone, and hourly annual Daily Light Integral values on a user-defined grid. It then seamlessly compares the data against seasonal light and soil temperature requirements of listed cultivars to evaluate their suitability within the constraints of the analysis area. A basic plant dataset is created that is open to expansion based on plants growth data availability. This automated workflow can be employed by agriculturalists, urban planners, and landscape designers to perform vegetation selection for applications such as urban greening in dense contexts or vertical farms.
Generating Residential Layout Based on AI in the View of Wind Environment
Authors: Ying X Y , Qin X Y , Chen J H , Gao J
Published: December 2021

There is a contradiction between the high-density residential area development form and comfortable outdoor physical environment. The existing studies on wind environment of high-rise residential areas only provide the guidance for the simple general layouts, which cannot cope with the fact that most high-rise residential areas are mixed of point buildings and board buildings, and it would cost a lot of time and resources to carry out computer simulation of each layout. This paper presents a new tool, which uses the automatic optimization function of genetic algorithm and the prediction function of fully convolutional neural network to integrates three functions: the automatic generation of high-rise residential layout, the simulation of wind environment and the comparison for optimization, to learn plan scheduling and obtain the optimal solution for high-rise residential layout under specific plot ratio and plot conditions, provides guidance for today’s fast-paced architectural design.
A climate-based moisture index approach for hygrothermal analysis in Australia
Authors: Javed Haniya , Brambilla Arianna , Strang Marcus
Published: December 2021

In Australia, one-third of new constructions are affected by condensation and about 50% of buildings suffer from mould risk, mainly due to inappropriate design and management strategies. Despite the potential structural damage and serious health hazards, there is a lack of preventive moisture management strategies at the legislative level. The first hygrothermal management provisions were adopted in the National Construction Code only in 2019, with very general indications that correlate the breathability of the membranes with the climate zone. However, the building code identifies only eight zones for the entire Australia, which were originally developed for thermal analysis and energy efficiency provisions. The result is a coarse climate grid that clusters locations with highly variable humidity conditions. This paper undertakes a semi-empirical approach to identify whether the current climate zones are suitable for hygrothermal purposes. This research represents the first step towards an Australian-specific moisture risks management framework, and it advances the discussion about the suitability of the current hygrothermal design and construction policy and practices. The outcomes reveal the highly variable moisture indices obtained for the different representative cities, affirming the inappropriate use of existing climate zone clustering for hygrothermal assessment purposes.
Utilization of Climate Files Predicting Future Weather in Dynamic Building Performance Simulation – A review
Authors: Nielsen C N , Kolarik J
Published: December 2021

As the climate is changing and buildings are designed with a life expectancy of 50+ years, it is sensible to take climate change into account during the design phase. Data representing future weather are needed so that building performance simulations can predict the impact of climate change. Currently, this usually requires one year of weather data with a temporal resolution of one hour, which represents local climate conditions. However, both the temporal and spatial resolution of global climate models is generally too coarse. Two general approaches to increase the resolution of climate models - statistical and dynamical downscaling have been developed. They exist in many variants and modifications. The present paper aims to provide a comprehensive overview of future weather application as well as critical insights in the model and method selection. The results indicate a general trend to select the simplest methods, which often involves a compromise on selecting climate models.