bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of laboratory experiments to determine critical moisture condition of CLT constructions
Authors: Olsson Lars , Lång Lukas , Bok Gunilla , Mjörnell Kristina 
Published: December 2023

Abstract
There is an increased interest in using Cross-laminated timber (CLT) in construction, but many buildings are erected without weather protection, which poses a risk of moisture impact if wood is exposed to precipitation during construction. The construction industry argues that there are no documented critical moisture levels for CLT and no specific test method. In the study, a laboratory test set-up was developed to study mould growth under realistic and controlled climatic conditions after exposure to distilled water and spore suspension. In the experiments, small test specimens of CLT structures were exposed to distilled water for 1 day or 1 week. During the development of the method it was found that exposed for one day and then given the opportunity for open drying did not give rise to mould growth. On the other hand, growth occurred on surfaces that could not dry immediately, for example at connection points. For specimens exposed for one week, mould growth arose regardless of whether the surfaces could dry immediately or not. The conclusions apply primarily to the climates studied. The methodology needs to be further developed, with other scenarios being studied, and calibrated against samples exposed to outdoor air, dust, dirt and rainwater.
Impact of different water penetration criteria and cavity ventilation rates on the risk of mold growth in timber frame walls with brick veneer cladding
Authors: Kahangi Shahreza S , Abdul Hamid A 
Published: December 2023

Abstract
The present paper investigates the impact of different water penetration criteria on the risk for damage in a common type of building envelope in Nordic countries, timber frame walls with brick masonry veneer. The studied walls are evaluated based on one damage criterion, the risk of mold growth. The study investigates several parameters: water penetration criterion, type of moisture source (uniformly distributed or point source) and its position in the wall assembly, air change rate (ACR) (representing different workmanship scenarios), wind-driven rain (WDR) coefficient, and locations (Gothenburg and Rensjön, with different average annual rainfall and temperature). Two criteria on how to implement water penetration are compared: a) a commonly accepted reference model that assumes one percent of all wind-driven rain deposited on the façade to penetrate the clay brick cladding, and b) a new criterion stating that 3.8% of WDR penetrates when the water content of the brick veneer cladding is above 90% of its saturation capacity. The simulation is done for a thirteen-year period with WUFI Pro and WUFI 2D. The results indicate the greater importance of implementing water penetration compared to ventilation in cavities. Further, the findings suggest that the moisture source’s location significantly impacts the mold growth risk. The results also show that the choice of the WDR coefficient affects the risks, which suggests that this factor needs accurate quantification for hygrothermal analyses. The results in this study suggest that an effective measure for the design/maintenance of such walls should incorporate: a) limiting the amount of water penetrating through the cladding, particularly stopping water from reaching the sensitive elements, i.e., timber studs, b) removing extruded mortar stemming from poor workmanship, if any, which may act as a capillary bridge.
Experimental and Numerical Investigation of Mould Growth Risk on Wooden Load-Bearing Structure in Hemp-lime Concrete Facades
Authors: Petersen S , Svendsen S , Hahn-Hundsdahl M 
Published: December 2023

Abstract
The need for reducing the environmental impact of the production of building materials has accelerated the emergence of new types of bio-based façade systems. Some of these systems are claimed to have hygro-thermal properties that eliminate the need for a dedicated air and/or vapour barrier as a part of the façade buildup. This paper presents a risk assessment of moisture-related deterioration of the wooden load-bearing structure in an existing hemp-lime concrete building façade system constructed without a dedicated air or vapour barrier in Aarhus, Denmark. Destructive investigation found no mould on structure. The façade was then modelled in WUFI 2D and calibrated using time series data from field measurements of temperature and relative humidity internally in the construction and in its surroundings. The calibrated WUFI model was used to simulate the annual moisture cycle using different initial conditions and weather data. The simulation output was analysed for the risk of mould growth at the wooden load-bearing structure using the Mould Growth Index. Results indicate that the initial moisture content of materials, the position of the wood structure, and the season of construction completion is important to consider to minimise risk of mould growth in the build-up.
Equilibrium Moisture Content of High Strength Concrete Used in Hollow Core Slabs
Authors: Vänttinen Kari , Tuominen Olli , Tuominen Eero , Valovirta Ilkka , Karjala Pauli , Tuurala Ilkka , Vinha Juha 
Published: December 2023

Abstract
The aim of this study was to measure equilibrium moisture content of hollow core slabs on both hygroscopic and capillary ranges. Because of the fabrication method of hollow core slabs, concrete grades and compacting methods used in the production differ from those used with reinforced concrete structures and elements. Test samples were taken from two slabs delivered by different manufacturers. Both slabs had similar geometry and were made of C50/60 grade concrete. Hygroscopic moisture equilibrium values were determined in climate chambers. Thin test specimens were used to perform tests within a reasonable time. Hygroscopic moisture equilibrium was measured at high relative humidities (RH), from 85 to 97 % RH. These measurements could be connected to the measurements of the retention curve done by a pressure plate. Measurements done in climate chambers and by pressure plate provided coherent results within the accuracies of these two methods. The results of two concrete slabs representing two different manufacturers differed significantly from each other, indicating the deviation of hygrothermal material properties even if the studied slabs were almost identical in many respects. Measured data is especially useful in modelling as well as analysing moisture damages.
Ruggedness test made with mortars by free water intake test
Authors: Tuominen Eero , Vinha Juha 
Published: December 2023

Abstract
Capillary movement in porous building materials is modelled by unsaturated flow. Material property needed for the calculations is liquid water diffusivity which is usually estimated by water absorption coefficient and capillary saturation moisture content. While determining of water absorption coefficient can be done according to EN-ISO 15148:2002 there is still lack of knowledge about sources of uncertainty in the experiment. In this paper author presents results of ruggedness tests done with mortar. The sources of errors investigated here was the shape and water inflow area of the specimen. Some specimens were also deprived of side sealing and sealing of upper surface as it was known to have impact on results. Results shows there is no considerable impact on measured capillary properties if the specimen sides are sealed or not. Nor does affect the immersed surface area of the specimen. The shape of the immersed surface instead has significant impact on values of both water absorption coefficient and capillary saturation of the specimen.
Measurement of water vapor transmission properties using the cup method – error caused by air buoyancy
Authors: Richter Jan , Staněk Kamil , Kopecký Pavel , Tywoniak Jan 
Published: December 2023

Abstract
The determination of water vapor transmission properties is commonly performed using the cup method. The method is based on periodic weighing of the cup assembly over time. If the air density surrounding the balance differs between weighings, measured change of mass is affected by the difference of ambient air buoyant force. For the correction of this effect can be used a mathematical formula presented in the literature and standards. The ASTM E96 states that this correction is important if observing changes of water vapor mass 0–100 mg. This paper therefore analyses possible errors of measured water vapor transmission properties based on a single 100 mg mass change without applying the buoyancy correction. It was found that for most common samples of building materials (sd < 3 m) and regular sizes of cup assemblies the error of a single mass change measurement can be up to ca. ±13 %, while assemblies with higher volume, higher mass, or more vapor tight samples can experience an error up to ±26 %. However, the vapor transmission properties are usually determined based on five consecutive weight changes. In that case the error can be up to five times lower (±2.5–5 %). Regarding the formula of the buoyancy correction the most important parameter was found to be the chosen volume of the cup assembly which, however, depends on particular setup and sample air-permeance. Only two extreme scenarios regarding this topic were analyzed while the full understanding of the accurate correction is still unsolved in its complexity.
Weather protection at the construction site: work environment and conditions for moisture and mould growth on massive timber
Authors: Bolmsvik Å , Eriksson O , Tengberg C Svensson , Johansson P 
Published: December 2023

Abstract
During the last decade, the use of timber (especially massive timber) has increased worldwide, mainly driven by anticipated environmental benefits. However, there is debate on how to handle the susceptibility against microbial growth for wooden constructions, especially during the construction phase. Sometimes full weather protection is used to avoid exposing the wooden material to outdoor conditions, but oftentimes the structures are fully exposed to precipitation. In an earlier study, one construction site using a full weather protection was studied, and the results showed promising results on the improved hygrothermal conditions and reduced risk of mould growth. Moreover, the site contractor also indicated improved work environment and productivity, however, this was not included in that study. This present study aims to investigate the effects of using full weather protection during construction in seven different construction projects to follow-up and broaden the earlier single project study. The studied aspects include the hygrothermal conditions, potential of mould growth, and influence on the work environment.
Temperature and relative humidity were measured and analysed. Samples of cross-laminated timber (CLT) were analysed using a microscope, and the results are compared to theoretical mould growth potential. This is measured both inside the weather protection and outside at the seven construction projects. Furthermore, a work environment questionnaire is distributed to workers at the sites to collect the perceived work environment using a full weather protection.
The results of the study partly confirm the conclusions from the earlier study, i.e., reducing the risk of mould growth and causing a slightly warmer and dryer conditions than outside. In addition, the results indicate an improved work environment. The majority of the interviewees wishes a weather protection in their next project regarding the work environment.
Karsten tube analysis for joint mortar identification in masonry
Authors: Stenholt-Jacobsen Rasmus , Hansen Kurt Kielsgaard , Rörig-Dalgaard Inge 
Published: December 2023

Abstract
The present work examines the Karsten tube penetration test to identify mortar types in existing masonry, for mortars containing air-lime or hydraulic binders. Mortar type identification is e.g. of relevance for the reusability of the fired clay bricks in the masonry, where a hydraulic binder content makes the mortar removal process significantly more difficult. The Karsten tube test makes it possible to make a simple and non-destructive mortar analysis on-site assessing the water absorption of the mortar, via the surface of the mortar joint alone. The present approach considers both the effect of the surrounding bricks and the surface finish of the pointing. Furthermore, the setup masks the brick surface exposed under the Karsten tube to focus the exposure on the mortar. Three different mortar types in existing masonry were tested: air-lime mortar, air-lime/hydraulic lime mortar and air-lime/cement mortar. The results showed linear water absorptions, which were clearly distinguishable for the hydraulic and non-hydraulic binders during the 15-minute tests. The measurement results in the present work document how the Karsten tube penetration test can be used for simple and non-destructive identification of joint mortar types determining whether the masonry was constructed with air-lime mortar or mortar containing hydraulic binders.
Modelling Rain Water Ingress in Hygrothermal Simulations
Authors: Van Den Bossche Nathan , Van Linden Stéphanie 
Published: December 2023

Abstract
The hygrothermal response of building envelope components is often studied by means of numerical Heat-Air-Moisture (HAM) simulation models. There models aim to capture the most important physics that affect the transport and storage of heat and moisture due to climatic excitations. For a lot of climates and components the wind driven rain load is the main driver for moisture uptake in the construction, and as well, the trigger of important degradation phenomena e.g., freeze-thaw damage, mold growth, wood decay, corrosion, salt transport, algae growth. When building components are subjected to wind driven rain loads and driving rain wind pressures, capillary uptake in porous materials is typically considered in models, but rain water often infiltrates directly into different layers of the construction and these infiltrations may have a significant impact on the hygrothermal behavior. This paper offers a straightforward methodology to take the rain water management of building envelope components into account in hygrothermal simulations. For different types of façade systems a categorical approach is presented to simulate rain water ingress into the different layers. Next to that, also the drainage and retention is discussed in detail. Finally, this methodological approach is embedded in the SAMiRA-framework, which comprises 3 performance levels for each input parameter of the simulations: (i) Superior, (ii) Advanced, (iii) Minimum Requirement Approach. Hence, 3 different levels are offered to implement rainwater infiltration in hygrothermal simulations.
Assessing Statistical Indices for Calibrating Building Performance Simulation Models via Continuous Time Series
Authors: Freudenberg P. , Dresel M. D. , Batayneh Z. 
Published: December 2023

Abstract
In engineering planning practice, building simulation is becoming increasingly crucial for evaluating buildings’ energetic and thermal behaviour. The appropriate application in the form of models that represent reality precisely, therefore, faces the challenge of realistic parameter specification for uncertain BES model properties. Many of them can only be restricted to a probable range of values. Additional knowledge can be obtained for the case of available measurement data via inverse modelling. This approach minimises cost function values representing discrepancies between associated time series (measured and simulated data sets). Much research has been published in this field for energy consumption characteristics. These approaches differ in several aspects from measured continuous physical state quantities. This article applies general cost indices to air temperature measurement series. For isolated effects such as time delay and amplitude attenuation, the impact on the characteristic values is examined, and their response is evaluated. This survey leads to the conclusion that there is no single parameter suitable for identifying all effects, and a combination is recommended. A new proposal is made for such a combined statistical index, and exemplary applied for measured temperature curves from a castle near Potsdam.
Predicting the performance of hybrid ventilation in buildings using a multivariate attention-based biLSTM Encoder – Decoder
Authors: Chaudhary Gaurav , Johra Hicham , Georges Laurent , Austbø Bjørn 
Published: December 2023

Abstract
Hybrid ventilation is an energy-efficient solution to provide fresh air for most climates, given that it has a reliable control system. To operate such systems optimally, a high-fidelity control-oriented modesl is required. It should enable near-real time forecast of the indoor air temperature based on operational conditions such as window opening and HVAC operating schedules. However, physics-based control-oriented models (i.e., white-box models) are labour-intensive and computationally expensive. Alternatively, black-box models based on artificial neural networks can be trained to be good estimators for building dynamics. This paper investigates the capabilities of a deep neural network (DNN), which is a multivariate multi-head attention-based long short-term memory (LSTM) encoder-decoder neural network, to predict indoor air temperature when windows are opened or closed. Training and test data are generated from a detailed multi-zone office building model (EnergyPlus). Pseudo-random signals are used for the indoor air temperature setpoints and window opening instances. The results indicate that the DNN is able to accurately predict the indoor air temperature of five zones whenever windows are opened or closed. The prediction error plateaus after the 24th step ahead prediction (6 hr ahead prediction).
Cooling Demand and Indoor Temperatures of a Detached House in Southern Finland: Feasibility of a Monthly calculation Method
Authors: Rantanen Olli , Järvistö Socorro , Valovirta Ilkka , Vinha Juha 
Published: December 2023

Abstract
The aim of this study was to compare dynamic thermal modelling with a monthly calculation method based on a European standard and Finnish regulations. Effect of thermal insulation level of a building envelope, solar shading, solar heat gain coefficient and window area on cooling demand were also studied. Increasing the thermal insulation of building shell increased indoor temperatures and hence cooling demand considerably. Solar shading by blinds between window panes decreased indoor temperatures effectively, indicating the performance of passive cooling in Finnish climate. There were rather large differences between calculated indoor temperatures and cooling demands between the two methods although both methods were able to take into account differences between variations in building shell. According to the study, the monthly calculation method underestimates the cooling need which can be significant considering the energy consumption of buildings. Therefore, it is recommended to investigate both summer temperatures and the cooling energy needs of detached houses by modelling.
How reliable is the co-heating test?
Authors: Ritosa K , Saelens D , Roels S 
Published: December 2023

Abstract
The predicted or designed envelope’s energy performance often differs from the in-reality achieved one and this phenomenon, known as the building fabric performance gap, is usually caused by poor workmanship or material properties differing from ones specified in the design phase. To bridge this gap, and quantify the achieved envelope’s thermal characteristics, different methodologies based on dedicated on-site monitoring campaigns are applied. One of the recognized methods for evaluating the building’s Heat Loss Coefficient (HLC) is the co-heating test, during which a vacated house is submitted to elevated temperatures while the delivered heat and the indoor and outdoor environments are precisely monitored. In recent years, researchers are turning towards non-intrusive methods and to validate them the co-heating test is often recognized as the benchmark. However, the validity of this approach is hard to prove since the reference is undefined, therefore, the aim of this work is to evaluate the reliability of the HLC estimation by the co-heating test. Since in this investigation actual reference values are required, such an assessment was performed by applying the co-heating testing procedure and established statistical models to artificially generated data which resemble ideal monitoring campaigns. In this work, the prescribed co-heating testing procedure and statistical models are applied to a simulated sample size of single-family dwellings characteristic of Flanders. The main aim here is to assess the trends in the results when different estimation approaches are applied to the same ideal monitoring dataset. Moreover, the analysis can be performed on a large sample size and, since indoor conditions are prescribed, outdoor conditions can be manipulated in a way to isolate the effect of different weather parameters on the estimation.
A review of the 1-2 apartment residential building stock in Lithuania based on an analysis of Energy Performance Certificates
Authors: Monstvilas E , Borg Simon Paul , Norvaišienė R , Banionis K , Bliūdžius R 
Published: December 2023

Abstract
One of priorities of the EU’s climate change policy is the energy performance of buildings. This is reflected primarily through the series of Directives the EU has enacted along the years, but is most precisely conveyed in the Energy Performance of Buildings Directive (EPBD). As part of the European Union, Lithuania has enacted its own long-term strategy aimed at transforming the current building stock in one which is more energy efficient. Building energy certification, legalized in accordance with the requirements of the directive is the primary tool used to evaluate the energy-efficiency of a building, which includes determination of the energy consumption of a building and subsequently assigning it with an energy performance class. Energy performance certificates (EPC) are obligatory for new and existing buildings in all European Union (EU) member states and provide not only a description of the energy performance characteristics of individual buildings, but are also useful source of legal information for determination of the achievements of building energy efficiency improvement strategy. Despite the current wide spread presence of EPC analyses in other European countries, similar information on the national EPC register of Lithuania is still hardly present in research studies. To this effect this paper presents a detailed overview of the stock of Lithuanian residential 1-2 apartments buildings using data from the national EPC register. The results obtained present the impact of the implementation of EPBD on Lithuanian residential 1-2 apartments buildings, including changes in thermal insulation of building elements, heating system typology, energy consumption and CO2 emissions.