Journal articles on the topic 'Hygrothermal and energy performance'
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1
Blumberga, Andra, Ritvars Freimanis, Edite Biseniece, and Agris Kamenders. "Hygrothermal Performance Evaluation of Internally Insulated Historic Stone Building in a Cold Climate." Energies 16, no. 2 (January 12, 2023): 866. http://dx.doi.org/10.3390/en16020866.
Abstract:
In most cases, internal insulation is the only solution to improve the energy efficiency of historic buildings. However, it is one of the most challenging and complex energy efficiency measures due to changes in boundary conditions and hygrothermal behavior of the wall, particularly in cold climates. This study presents the long-term monitoring of the hygrothermal performance of an internally insulated historic stone wall building. The study aimed to assess the hygrothermal behavior of the dolomite wall if mineral wool insulation is applied internally on the north-east wall in the rooms with and without high internal moisture load. The measurements included temperature, relative humidity, water content, and heat flux. Monitoring results are compared with 1D hygrothermal simulations and a building energy consumption simulation. The in situ measurement results and hygrothermal assessment shows energy consumption decreased by 55% with relative humidity under the insulation staying belove 60% for most of the time, with short periods of increase over 80%. Energy consumption simulation shows an energy saving potential of up to 72% in the case of proper energy management.
2
Lawrence, Mike, Enrico Fodde, Kevin Paine, and Pete Walker. "Hygrothermal Performance of an Experimental Hemp-Lime Building." Key Engineering Materials 517 (June 2012): 413–21. http://dx.doi.org/10.4028/www.scientific.net/kem.517.413.
Abstract:
The use of hemp-lime as a construction technique is a novel approach which combines renewable low carbon materials with exceptional hygrothermal performance. The hemp plant can grow up to 4m over a four month period, with a low fertilizer and irrigation demand, making it very efficient in the use of time and material resources. All parts of the plant can be used the seed for food stuffs, the fibre surrounding the stem for paper, clothing and resin reinforcement, and the woody core of the stem as animal bedding and aggregate in hemp-lime construction. The unique pore structure of the woody core (shiv) confers low thermal conductivity and thermal and hygric buffering to hemp-lime. The construction technique promotes good air tightness and minimal thermal bridging within the building envelope. All these factors combine to produce low carbon, hygrothermally efficient buildings which are low energy both in construction and in use, and offer opportunities for recycling at end of life. This paper reports on the hygrothermal performance of an experimental hemp-lime building, and on the development of a computerized environmental model which takes account of the phase change effects seen in hemp-lime.
3
Olaoye, Toba Samuel, Mark Dewsbury, and Hartwig Kunzel. "A Method for Establishing a Hygrothermally Controlled Test Room for Measuring the Water Vapor Resistivity Characteristics of Construction Materials." Energies 14, no. 1 (December 22, 2020): 4. http://dx.doi.org/10.3390/en14010004.
Abstract:
Hygrothermal assessment is essential to the production of healthy and energy efficient buildings. This has given rise to the demand for the development of a hygrothermal laboratory, as input data to hygrothermal modeling tools can only be sourced and validated through appropriate empirical measurements in a laboratory. These data are then used to quantify a building’s dynamic characteristic moisture transport vis-a-vis a much more comprehensive energy performance analysis through simulation. This paper discusses the methods used to establish Australia’s first hygrothermal laboratory for testing the water vapor resistivity properties of construction materials. The approach included establishing a climatically controlled hygrothermal test room with an automatic integrated system which controls heating, cooling, humidifying, and de-humidifying as required. The data acquisition for this hygrothermal test room operates with the installation of environmental sensors connected to specific and responsive programming codes. The room was successfully controlled to deliver a relative humidity of 50% with ±1%RH deviation and at 23 °C temperature with ±1 °C fluctuation during the testing of the water vapor diffusion properties of a pliable membrane common in Australian residential construction. To validate the potential of this testing facility, an independent measurement was also conducted at the Fraunhofer Institute of Building Physics laboratory (IBP) Holzkirchen, Germany for the diffusion properties of the same pliable membrane. The inter-laboratory testing results were subjected to statistical analysis of variance, this indicates that there is no significant difference between the result obtained in both laboratories. In conclusion, this paper demonstrates that a low-cost hygrothermally controlled test room can successfully replace the more expensive climatic chamber.
4
Pungercar, Vesna, and Florian Musso. "Hygrothermal Performance of Salt (NaCl) for Internal Surface Applications in the Building Envelope." Materials 15, no. 9 (May 2, 2022): 3266. http://dx.doi.org/10.3390/ma15093266.
Abstract:
Salt (NaCl), as a by-product from the potash and desalination industry, can be the solution to the scarcity of building materials and might replace more energy-consuming materials. However, salt carries the risk of deliquescence in humid environments. This study conducted fundamental research on the hygrothermal performance of salt for internal surface applications in the building envelope in six different climate conditions. In addition, salt’s performance was also compared with that of gypsum in similar applications. The simulation models (using WUFI®Pro, WUFI®Plus) and in situ measurements were applied to investigate the hygrothermal consequences of the incorporation of salt on the thermal envelope, indoor environment, and energy consumption. Our studies revealed that salt provided the best hygrothermal responses without Heating, Ventilation, and Air Conditioning (HVAC) in very hot-dry and the worst in very hot-humid climates. With an energy-efficient thermal envelope and HVAC, salt can also find an indoor application in temperate, continental, and subpolar climates. In comparison to gypsum, salt has a slightly higher energy demand (heating, cooling, and dehumidification) due to its higher thermal conductivity and moisture resistance. This study fills the knowledge gap on salt’s hygrothermal performance and shows the potential in its utilization.
5
Heracleous, C., R. Panagiotou, I. Ioannou, A. Michael, and M. Philokyprou. "Hygrothermal Performance of Adobe Structures." IOP Conference Series: Earth and Environmental Science 1196, no. 1 (June 1, 2023): 012059. http://dx.doi.org/10.1088/1755-1315/1196/1/012059.
Abstract:
Abstract Vernacular architecture incorporates many cooling and heating passive design strategies related to the structural envelope, the different architectural arrangements and the way of living of the inhabitants. Adobe walls are considered to be high thermal mass masonries, as they have the ability to store thermal energy. The high thermal inertia of these materials regulates indoor temperature variations through considerable time lags, thus contributing to the improvement of thermal comfort conditions. This study deals with the environmental behaviour of an adobe historic building in the rural area of Nicosia, Cyprus. The aim of this study is the investigation of the hygrothermal performance of the external adobe masonry walls of the structure under study. For this purpose, in-situ long-term monitoring is currently being carried out, focusing on the indoor and outdoor environmental conditions of a south wall of a room which has two exposed surfaces, the north towards the street and the south towards a courtyard. The south wall is being monitored with temperature/moisture sensors, installed at various locations along its thickness and height. In situ monitoring is complemented with laboratory measurements of the thermophysical (thermal conductivity, porosity, and sorptivity) properties of the main masonry material (adobes). Rising damp height, time of wetness, thermal inertia and decrement factor have all been calculated based on the laboratory and in-situ measurements. The results are analysed in terms of existing standards and analytical equations. The findings of this research may be used to evaluate the overall thermal performance of historic adobe buildings and the effectiveness of adobe walls in the improvement of indoor comfort conditions.
6
Nagy, Balázs, and Tamás K. Simon. "Energy and hygrothermal performance of builtin mineral wool thermal insulations." MATEC Web of Conferences 163 (2018): 08001. http://dx.doi.org/10.1051/matecconf/201816308001.
Abstract:
The paper analyses the monitoring measurement results on energy performance and hygrothermal behaviour of built-in rock and glass mineral wool thermal insulations in an energy efficiently refurbished typical single-family dwelling house in Hungary. The experimental monitoring measurements included an external weather station; internal air condition measurements; temperature, relative humidity and heat flux sensors in the layers of the facade and attic. An energy meter was installed into the heating systems. Apart from the insulated one, the energy consumption of an uninsulated but identical family house close by to the refurbished one was monitored as control. In the paper, apart from comparing the energy performance of the monitored buildings, the conjugated heat and moisture behaviour of the built-in mineral wool insulations were examined and compared to their design values and conditions. The temperature and moisture correction factors were evaluated. The paper presents laboratory measurements on the thermal conductivity of built-in and etalon mineral wool insulation samples also. The circumstances were set according to the experienced built-in conditions in the monitored buildings and compares the energy and hygrothermal performance of new and aged insulations.
7
Ganguly, Shashwat, Fan Wang, and Michael Browne. "Comparative methods to assess renovation impact on indoor hygrothermal quality in a historical art gallery." Indoor and Built Environment 28, no. 4 (July 8, 2018): 492–505. http://dx.doi.org/10.1177/1420326x18785791.
Abstract:
This paper presents a set of methods for renovation impact assessment of indoor hygrothermal conditions in a culturally significant historical building, functioning as an art gallery. A new parameter, Renovation Impact Index (RII), was developed and used for the assessment. The RII is defined as the performance gradient of indoor hygrothermal conditions over two annual periods, the year before and the year after the renovations. The performances of the two most critical parameters to artwork conservation – temperature (T) and relative humidity (RH) – were assessed with respect to conservation specifications. RII was defined over two windows: tight set points specified in the BS 5454 : 2000 Conservation Standard and a relaxed strategy for energy saving potential. ‘Global’ Performance Index was obtained as a combined effect of T and RH. A seasonal analysis was undertaken for detailed study of renovation impact on individual seasons. Results identified the positive effects of the renovation solutions, with the indoor environment then being less influenced by outdoor weather changes. In addition to energy savings of 27%, the positive RII estimate showed quantitative improvement in hygrothermal performance. The proposed methods can be extended to other renovation projects in similar buildings to assist building managers to target future improvements.
8
Pedroso, Marco, Maria da Glória Gomes, José Dinis Silvestre, Ahmed Hawreen, and Inês Flores-Colen. "Thermophysical Parameters and Hygrothermal Simulation of Aerogel-Based Fibre-Enhanced Thermal Insulating Renders Applied on Exterior Walls." Energies 16, no. 7 (March 27, 2023): 3048. http://dx.doi.org/10.3390/en16073048.
Abstract:
Aerogel-based renders have been the subject of research in the last few years due to their high thermal insulation characteristics and the need for buildings to become more energy-efficient. This study compares the hygrothermal behaviour of an aerogel-based render (reference) with the same base formulation, replacing the powder with three different fibres (aramid 0.5%, sisal 0.1%, and biomass 0.1%, by total volume) that can be used in buildings’ envelopes. The experimental programme allowed us to characterise and compare the thermophysical properties of the different formulations and then simulate the hygrothermal performance of these solutions when applied to walls for different climatic conditions, considering additional parameters such as total water content, drying potential, water content levels, and thermal insulating performance. These thermophysical parameters were then included in hygrothermal numerical simulations. The results allowed us to verify that the incorporation of fibres improved the hygrothermal properties due to lower capillary absorption and higher water vapour permeability. These renderings showed a high potential for application to building envelopes in different climatic conditions, improving their energy efficiency by up to 20% when compared to other conventional solutions.
9
Muñoz-González, Carmen, Ángel León-Rodríguez, Rafael Suárez Medina, and Catherine Teeling. "Hygrothermal Performance of Worship Spaces: Preservation, Comfort, and Energy Consumption." Sustainability 10, no. 11 (October 23, 2018): 3838. http://dx.doi.org/10.3390/su10113838.
Abstract:
The energy problem, one the most important on a global scale, greatly affects the environment. Much of the current energy consumption occurs in existing buildings, including heritage buildings with varying protected status. Energy intervention and heritage conservation conflict to some extent, as research focuses more on the search for improved energy efficiency solutions for materials and systems than on their application to heritage buildings. This study describes experimental research on environmental conditioning techniques in spaces of worship in a temperate climate in southern Spain. Buildings were monitored and assessed in the implementation of different environmental techniques—active and combined (passive and active)—with the aim of improving the thermal comfort conditions of the faithful while preserving the cultural heritage of these buildings. The need for a control system of RH and the air system was concluded, as well as radiant floors and radiators, which, in the considered case studies, would barely affect the artworks. 24- and 12-h operation are better suited to heritage preservation than occasional use. All operation schedules are valid for thermal comfort.
10
Salonvaara, Mikael, Philip Boudreaux, Andre Desjarlais, Florian Antretter, and Eric Werling. "Validation of Hygrothermal Simulations with Wall Performance Experiments in an Environmental Chamber." E3S Web of Conferences 172 (2020): 04010. http://dx.doi.org/10.1051/e3sconf/202017204010.
Abstract:
Oak Ridge National Laboratory is developing a web tool, built on a rule-based expert system, that aids stakeholders in designing energy-efficient moisture-durable walls. Currently, the tool’s expert system database is mostly populated with expert opinion, but work is being done to incorporate durability assessment based on stochastic hygrothermal modeling. Chamber experiments have been conducted to validate the hygrothermal models. The measured temperature and humidity have been compared with those predicted by the hygrothermal model. Experiments and comparison to one-dimensional hygrothermal modeling results were completed with two walls, a Structural Insulated Panel (SIP) based wall and a Concrete Masonry Unit (CMU) based wall. The two walls were succumbed to typical Chicago weather in ORNL’s Heat, Air and Moisture chamber. The walls were sequentially exposed to different scenarios, including diffusion, wetting, air leakage and solar radiation. For the most part, the hygrothermal simulations can be successfully used to predict the performance of these wall systems for the moisture transport phenomenon. Errors between measured and simulated values decreased as measurements got closer to the interior side of the wall. The root mean square error was larger for relative humidity (up to 17.5%-RH for CMU) than for temperature (up to 4.5°C for CMU wall). The errors were larger for the CMU wall than the wood frame wall. The phenomenon, including liquid water, caused large discrepancies between measurement and simulation results, and simulated results showed slower drying of materials than measured results. The one-dimensional nature of the simulation model made simulating air leaks difficult but not impossible.
11
Perez-Bezos, Silvia, Anna Figueroa-Lopez, Matxalen Etxebarria-Mallea, Xabat Oregi, and Rufino Javier Hernandez-Minguillon. "Assessment of Social Housing Energy and Thermal Performance in Relation to Occupants’ Behaviour and COVID-19 Influence—A Case Study in the Basque Country, Spain." Sustainability 14, no. 9 (May 6, 2022): 5594. http://dx.doi.org/10.3390/su14095594.
Abstract:
Evidence shows that people have a major impact on building performance. Occupants’ impact is especially important in social housing, where their occupants may present greater vulnerabilities, and their needs are not always considered. This study aims to analyse the socio-demographic influence in social rental housing concerning hygrothermal comfort and energy consumption in a case study located in Vitoria, Spain during the first 4-month period of 2020 and 2021 (during and after COVID-19 lockdown). An innovative data management system is included, where the users and administration can see in real-time the temperature and consumption in the dwellings. A 2-phase method has been applied; phase 1 is associated with outdoor climate conditions, building properties and social profile. Phase 2 determined the results in energy consumption, indoor hygrothermal comfort and occupant energy-use pattern. The results show that the comfort levels and energy consumption vary according to the analysed social profiles, as well as the heating activation periods and domestic hot water system usage. In conclusion, socio-demographic characteristics of social housing households influence the hygrothermal comfort of their dwellings, occupants’ behaviour and heating and domestic hot water energy consumption.
12
Yu, Shui, and Xu Zhang. "The Research on Hygrothermal Characterization of Eco-Fiber Materials." Advanced Materials Research 450-451 (January 2012): 786–90. http://dx.doi.org/10.4028/www.scientific.net/amr.450-451.786.
Abstract:
The development and research of new thermal insulation materials become a hot point due to the demand of building energy efficiency and high hygrothermal environment. Although there are many kinds of insulation materials in Chinese market, most of them are made from oil. It is very important to develop new thermal insulation materials to decrease the emission of CO2 and the use of non-renewable energy. The new materials have the function of reducing carbon emissions, improving the insulation performance of building envelope and indoor hygrothermal environment. However the research on hygrothermal characteristic of eco-fiber production is still kind of new work, such as water vapor permeability, thermal conductivity, water absorption coefficient, and isothermal sorption curve and so on, especially water absorption coefficient which doesn’t obey the classical model, according to the classical standards.
13
Salonvaara, Mikael, Andre Desjarlais, Antonio J. Aldykiewicz, Emishaw Iffa, Philip Boudreaux, Jin Dong, Boming Liu, et al. "Application of Machine Learning to Assist a Moisture Durability Tool." Energies 16, no. 4 (February 18, 2023): 2033. http://dx.doi.org/10.3390/en16042033.
Abstract:
The design of moisture-durable building enclosures is complicated by the number of materials, exposure conditions, and performance requirements. Hygrothermal simulations are used to assess moisture durability, but these require in-depth knowledge to be properly implemented. Machine learning (ML) offers the opportunity to simplify the design process by eliminating the need to carry out hygrothermal simulations. ML was used to assess the moisture durability of a building enclosure design and simplify the design process. This work used ML to predict the mold index and maximum moisture content of layers in typical residential wall constructions. Results show that ML, within the constraints of the construction, including exposure conditions, does an excellent job in predicting performance compared to hygrothermal simulations with a coefficient of determination, R2, over 0.90. Furthermore, the results indicate that the material properties of the vapor barrier and continuous insulation layer are strongly correlated to performance.
14
Ramos, N. M. M., I. M. Ribeiro, P. Santos, João M. P. Q. Delgado, and V. P. de Freitas. "Optimisation of Envelope Insulation for the Retrofit of an Educational Building." Defect and Diffusion Forum 312-315 (April 2011): 1137–42. http://dx.doi.org/10.4028/www.scientific.net/ddf.312-315.1137.
Abstract:
This paper presents ongoing work for the definition of an optimal design strategy for retrofitting educational buildings. The term “optimal design” refers to the selection of different retrofitting solutions to ensure an energy efficient building that can be developed which will not compromise hygrothermal comfort, indoor air quality, health and durability. In this paper, a selection model of thermal insulation thickness of envelope elements is developed, aiming the control of surface condensation and upgrade of hygrothermal comfort. The mathematical formulation of this model leads to a nonlinear program with linear objective function. The software Gmas/Minos was chosen to solve the optimization problem and to develop a calculation program to solve this specific application. The software Energy-Plus developed by the US Department of Energy was used to simulate hygrothermal performance of the building, providing results for a comparison with the developed simulation tool. The paper presents an example of an optimal design problem for a specific classroom of a retrofit educational building.
15
Paiho, Ojanen, Seppä, and Paavola. "Critical Performance Aspects of Retrofitting Apartment Buildings Using a Multifunctional Façade System." Buildings 9, no. 8 (August 13, 2019): 184. http://dx.doi.org/10.3390/buildings9080184.
Abstract:
There is huge market potential for energy refurbishment solutions in European buildings. This paper analyzes the challenges related to using a multifunctional energy efficient façade system, the “Meefs” system, in retrofitting multi-family apartment buildings. Similar challenges often occur also in other comparable façade renovation solutions. The focus is on hygrothermal performance even as other aspects are also discussed. After introducing the hygrothermal performance challenges of the Meefs system, numerical case analyses are performed in three different climatic conditions. The results for 26 cases are presented. A core result is that the drying of any exterior renovation system is mandatory to guarantee safe operation in different European climate conditions. This emphasizes proper design needs in all climates. Based on the analyses, design recommendations can be given for the Meefs system. In Central and Northern European climates, the system contains challenges which may hinder implementation in practice.
16
Yu, Shui, Mark Bomberg, and Xu Zhang. "Integrated methodology for evaluation of energy performance of the building enclosures: Part 4 – material characterization for input to hygrothermal models." Journal of Building Physics 35, no. 3 (September 20, 2011): 194–212. http://dx.doi.org/10.1177/1744259111420071.
Abstract:
Reviewing hygrothermal input data published in handbooks such as ASHRAE or ASTM, one often finds large range of variability in hygric properties of construction materials. Two factors that cause variability of these results are uncertainty of the test method and inadequate characterization of the material sample. Adequate characterization of the tested sample, despite being one of the most critical aspects of any material property measurement, is however frequently neglected. Yet, performing a high-precision test when the sample is not adequately characterized does not tell us what material was tested and therefore is not precise. Typically porous materials are characterized with geometrical properties such as mean pore size and pore-size distribution, but this approach bring as many new questions as it addresses. In this context, a position paper from CIB W40 written almost 10 years ago proposed using critical hygrothermal characteristics for material characterization as well as for the input to the models. Yet, with a few recently completed PhD, revisiting this issue may support the use of hygrothermal models for field performance calculations.
17
Ma, Xinyue, and Junyou Shi. "Effectiveness of Surface Treatment on Bonding Performance of Starch-Based Aqueous Polymer Isocyanate Wood Adhesive." Polymers 15, no. 4 (February 16, 2023): 988. http://dx.doi.org/10.3390/polym15040988.
Abstract:
The surface of a bonding material plays a key role in the bonding performance of an adhesive. Herein, we evaluated the effect of substrate surface treatment methods (sandpaper polished, chemical oxidation, and coupling agent) on the adhesive properties of starch-based aqueous polymer isocyanate (API) wood adhesive during hygrothermal aging. The birch substrate was processed with three different surface treatments, and the change of surface was analyzed by X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared spectroscopy (FT-IR), and Energy Dispersive Spectroscopy (EDS) methods. The results showed that the surface treatment had a great influence on the change of the shear strength of glued wood under hygrothermal conditions, and the silane coupling agent treatment could effectively reduce the decrease in the compressive shear strength of the adhesive. An XPS analysis indicated that the chemical oxidation modified wood surface polarity, and the coupling agent treatment in the wood surface formed a transition layer. After hygrothermal aging treatment, due to the different surface treatment of adhesive joint surface binding energy, the internal water absorption rate of starch-based API adhesives exhibited different failure modes of the adhesive joint. These findings indicate that the surface treatment effectively improved the durability of the adhesive joints.
18
Kaboré, Aguerata, Wahid Maref, and Claudiane M. Ouellet-Plamondon. "Hygrothermal Performance of the Hemp Concrete Building Envelope." Energies 17, no. 7 (April 4, 2024): 1740. http://dx.doi.org/10.3390/en17071740.
Abstract:
The search for environmentally friendly and low-carbon-footprint construction materials continues progressively. Researchers are now interested in innovative materials that connect with the principles of sustainable construction, and materials such as hemp concrete prove to be promising. This article presents the results of a study that aimed to evaluate the hygrothermal performance of hemp concrete integrated into the building envelope using the hygrothermal tool WUFI Pro 6.2. The simulation model was compared and verified with existing models before its utilization for this study. The results of this verification were in good agreement, which gave us more confidence in its application for further parametric studies of building envelopes in hot climate zones. Three wall systems were simulated: (i) a wall system with hemp concrete, (ii) a compressed earth block wall, and (iii) a cement block wall. The most important variables used in the simulations were the hygrothermal properties of the materials or wall components and the incident solar radiation. The simulation results showed that hemp concrete has good thermal performance and temperature and humidity regulation capabilities of the building envelope. The interior surface temperatures of the hemp concrete walls were between 22.1 °C and 24.6 °C compared to the compressed earth block and cement block walls, where the surface temperatures were between 22.0 °C and 27 °C and between 21.2 °C and 28.7 °C, respectively, and between 23 °C and 45 °C for the exterior temperatures. These values remain the same with the increase in exterior temperatures for hemp concrete walls. In conclusion, hemp concrete could be a great alternative material for use in construction for hot climate zones.
19
Koh, Chuen Hon (Alex), and Dimitrios Kraniotis. "Hygrothermal performance, energy use and embodied emissions in straw bale buildings." Energy and Buildings 245 (August 2021): 111091. http://dx.doi.org/10.1016/j.enbuild.2021.111091.
20
Abdellatef, Yaser, Mohammad Amil Khan, Asif Khan, Mehdi Iftekharul Alam, and Miroslava Kavgic. "Mechanical, Thermal, and Moisture Buffering Properties of Novel Insulating Hemp-Lime Composite Building Materials." Materials 13, no. 21 (November 6, 2020): 5000. http://dx.doi.org/10.3390/ma13215000.
Abstract:
Hempcrete is a sustainable biocomposite that can reduce buildings’ embodied energy while improving energy performance and indoor environmental quality. This research aims to develop novel insulating hemp-lime composites using innovative binder mixes made of recycled and low-embodied energy pozzolans. The characterization of composites’ mechanical and hygrothermal properties includes measuring compressive strength, splitting tensile strength, thermal conductivity, specific heat capacity, and moisture buffer capacities. This study also investigates the impact of sample densities and water content on compressive strength at different ages. The findings suggest that mixes with a 1:1 binder to hemp ratio and 300−400 kg/m3 density have hygrothermal and mechanical properties suitable for insulating infill wall applications. Hence, compressive strengths, thermal conductivity, and specific heat capacity values range from 0.09 to 0.57 MPa, 0.087 to 0.10 W/m K, and 1250 to 1557 J/kg K, respectively. The average moisture buffer value for all hempcrete samples of 2.78 (gm/m2 RH%) indicates excellent moisture buffering capacity. Recycled crushed brick pozzolan can enhance the hygrothermal performance of the hemp-lime composites. Thus, samples with 10% crushed brick have the lowest thermal conductivity considering their density and the highest moisture buffer capacity. The new formulas of hydrated lime and crushed brick have mechanical properties comparable to metakaolin and hydraulic lime formulas.
21
Salonvaara, Mikael, Seungjae Lee, Emishaw Iffa, Philip Boudreaux, Simon Pallin, André Desjarlais, and Antonio Aldykiewicz. "Selecting durable building envelope systems with machine learning assisted hygrothermal simulations database." Journal of Physics: Conference Series 2069, no. 1 (November 1, 2021): 012230. http://dx.doi.org/10.1088/1742-6596/2069/1/012230.
Abstract:
Abstract Hygrothermal simulations provide insight into the energy performance and moisture durability of building envelope components under dynamic conditions. The inputs required for hygrothermal simulations are extensive, and carrying out simulations and analyses requires expert knowledge. An expert system, the Building Science Advisor (BSA), has been developed to predict the performance and select the energy-efficient and durable building envelope systems for different climates. The BSA consists of decision rules based on expert opinions and thousands of parametric simulation results for selected wall systems. The number of potential wall systems results in millions, too many to simulate all of them. We present how machine learning can help predict durability data, such as mold growth, while minimizing the number of simulations needed to run. The simulation results are used for training and validation of machine learning tools for predicting wall durability. We tested Artificial Neural Network (ANN) and Gradient Boosted Decision Trees (GBDT) for their applicability and model accuracy. Models developed with both methods showed adequate prediction performance (root mean square error of 0.195 and 0.209, respectively). Finally, we introduce how the information supports guidance for envelope design via an easy-to-use web-based tool that does not require the end-user to run hygrothermal simulations.
22
Gholami, Mansoureh, Alberto Barbaresi, Patrizia Tassinari, Marco Bovo, and Daniele Torreggiani. "A Comparison of Energy and Thermal Performance of Rooftop Greenhouses and Green Roofs in Mediterranean Climate: A Hygrothermal Assessment in WUFI." Energies 13, no. 8 (April 19, 2020): 2030. http://dx.doi.org/10.3390/en13082030.
Abstract:
In urban areas, a considerable proportion of energy demand is allocated to buildings. Since rooftops constitute one-fourth of all urban surfaces, an increasing amount of attention is paid to achieving the most efficient shapes and component designs compatible with every climate and urban context, for rooftops of varying sizes. In this study, three types of rooftop technologies, namely insulated, green roof, and rooftop greenhouse, are evaluated for energy and thermal performance using computer simulations. Water surface exposure, absorption, and intrusion are the three important factors in the calculation of hygrothermal models that impact energy consumption and building envelope performance; however, a few studies are specifically focused on providing realistic results in multi-dimensional hygrothermal models and the assessment of the impact of moisture in roofing solutions. This paper aims at evaluating the performance of three different roofing technologies through a two-dimensional hygrothermal simulation in software WUFI. To accomplish this, a precise localized microclimate model of a complex urban context on the scale of a neighborhood was employed to evaluate the cooling and heating loads of the buildings, the impact of the water content in the green roof on the thermal behavior of the roof surface, and the feasibility of designing a building with nearly zero cooling needs. A two-story building in the city center of Bologna, Italy is modelled. Simulation results have shown that during the cooling period, the performance of the designed rooftop greenhouse is the most effective by 50% reduction in cooling loads. Besides, the impact of moisture in green roofs has been detected as a negative factor for thermal and energy performance of the building in the Mediterranean climate. The results ultimately highlighted the capability of passively-designed rooftop greenhouses to create a building with nearly zero cooling needs.
23
Pihelo, P., and T. Kalamees. "Hygrothermal Performance of Prefabricated Insulation Elements for Serial Renovation of Apartment Buildings in a Moderately Continental German Climate." Journal of Physics: Conference Series 2654, no. 1 (December 1, 2023): 012001. http://dx.doi.org/10.1088/1742-6596/2654/1/012001.
Abstract:
Abstract The reduction of energy use in the buildings is expected to be reached by fulfilling several requirements of the low- and nearly-zero energy buildings (nZEB) policy. The improvement of the energy performance of the building envelope and the service systems of the existing buildings offers great potential for energy savings as the annual replacement of the existing stock is only 1 to 2%. The efficient way to accomplish the purpose and global goals of the nZEB is to apply the integrated design process, development, and application of prefabricated insulation elements on a large scale. In this project, in the Berlin area of Germany, prefabricated timber frame insulation elements were designed for the external insulation of the envelope of the apartment building in the serial renovation process, with the thermal transmittance of the external envelope U external-wall = 0.14–0.16 W/(m2·K). In the current study, the potential hygrothermal risks and their effect on highly insulated multi-story apartment building envelope were analyzed. The study contained a set of hygrothermal analyses to ensure the moisture safety of highly insulated facade structures and the selection of materials from the perspective of hygrothermal performance and low risk of degradation. This research found that the risk of mold growth is high if timber elements are installed without protective measures against drying-out built-in moisture, wind-driven rain, and other weather conditions. The initial moisture content of the external concrete slab, to be considered critical, is 90 kg/m3, and the drying out period is longer than the covered with new layers constructions can sustain if a proper vapor control layer is not added between the existing moist wall and installed insulation elements. Furthermore, the wind barrier layer with high thermal resistance and vapor permeability of the installed insulation element helps to minimize the risk of mold growth. A careful analysis and selection of materials allow to design moisture-safe timber frame insulation elements and provide low thermal transmittance of renovated building envelopes. The results showed that before the final design and installation of the insulation elements, a thorough hygrothermal analysis of the original external envelope with actual climatic conditions and moisture loads must be realized.
24
Bagarić, M., I. Banjad Pečur, and B. Milovanović. "Application of developed facade panel from recycled CDW: A case study." Journal of Physics: Conference Series 2069, no. 1 (November 1, 2021): 012187. http://dx.doi.org/10.1088/1742-6596/2069/1/012187.
Abstract:
Abstract Using waste materials for production of sustainable exterior façade panel, that can be recycled at the end of its life cycle as part of a circular economy model, can significantly reduce environmental footprint of buildings and help preserve natural resources. The envelope system under consideration is a ventilated prefabricated wall panel from recycled construction and demolition waste (CDW). In this paper, hygrothermal simulations together with field monitoring of hygrothermal performance, energy consumption, indoor comfort and air quality in real environment conditions have been presented. Results show that developed panel is a robust, moisture-safe panel suitable for constructing energy high performing buildings. Thermal discomfort in summer is related to the architectural design of the building.
25
Valluzzi, Maria Rosa, Elisa Saler, Alberto Vignato, Matteo Salvalaggio, Giorgio Croatto, Giorgia Dorigatti, and Umberto Turrini. "Nested Buildings: An Innovative Strategy for the Integrated Seismic and Energy Retrofit of Existing Masonry Buildings with CLT Panels." Sustainability 13, no. 3 (January 23, 2021): 1188. http://dx.doi.org/10.3390/su13031188.
Abstract:
The Italian building heritage is aged and inadequate to the high-performance levels required nowadays in terms of energy efficiency and seismic response. Innovative techniques are generating a strong interest, especially in terms of multi-level approaches and solution optimizations. Among these, Nested Buildings, an integrated intervention approach which preserves the external existing structure and provides a new structural system inside, aim at improving both energy and structural performances. The research presented hereinafter focuses on the strengthening of unreinforced masonry (URM) buildings with cross-laminated timber (CLT) panels, thanks to their lightweight, high stiffness, and good hygrothermal characteristics. The improvement of the hygrothermal performance was investigated through a 2D-model analyzed in the dynamic regime, which showed a general decreasing in the overall thermal transmittance for the retrofitted configurations. Then, to evaluate the seismic behavior of the coupled system, a parametric linear static analysis was implemented for both in-plane and out-of-plane directions, considering various masonry types and connector spacings. Results showed the efficiency of the intervention to improve the in-plane response of walls, thus validating possible applications to existing URM buildings, where local overturning mechanisms are prevented by either sufficient construction details or specific solutions.
26
Bakkour, Amer, Salah-Eddine Ouldboukhitine, Pascal Biwole, Gael Godi, and Sofiane Amziane. "Experimental and Numerical Investigation of Hygrothermal Transfer through Bio-Based Materials: An Application to Wood–Cement Walls." Buildings 13, no. 12 (November 29, 2023): 2986. http://dx.doi.org/10.3390/buildings13122986.
Abstract:
In the context of the energy transition, new construction materials are emerging, notably bio-based materials such as wood concrete. This paper investigates the hygrothermal performance of walls constructed with wood–cement concrete. First, the thermal properties of wooden concrete, namely thermal conductivity, effusivity, and diffusivity, are experimentally characterized in both dry and wet conditions. Second, in situ measurements are carried out on a house in Lyon, a city in France, constructed with mono-layered wood–cement walls. This involves monitoring the temperature and relative humidity levels both inside and outside the building, as well as at three distinct positions within the wood walls over a 6-month period (from 20 April 2023 to 20 October 2023). The hygrothermal analysis at the center of the wall reveals that the wood wall effectively moderates fluctuations in the external temperature and relative humidity. Following this, a numerical study is performed to check the reliability of the adopted Reduced Heat, Air, and Mass (HAM) model to reproduce the hygrothermal performance of the wood–cement wall. The results show a strong agreement between the simulated and measured data, confirming the applicability of the ‘Reduced HAM’ model for the prediction of the hygrothermal behavior of wood–cement walls.
27
Liuzzi, Stefania, Simona Rigante, Francesco Ruggiero, and Pietro Stefanizzi. "Straw Based Materials for Building Retrofitting and Energy Efficiency." Key Engineering Materials 678 (February 2016): 50–63. http://dx.doi.org/10.4028/www.scientific.net/kem.678.50.
Abstract:
This work aimed to measure the hygrothermal properties of some different straw-based mix that could be used as building materials (panels or bricks). Straw is used to improve the hygrothermal performances of the final products. Several mix were produced adding different percentages of straw. Two types of fibers were used: wheat straw and bean straw. The results indicated that increasing the percentages of straw greater effects on the change of thermal properties can be appreciated. Furthermore the results also reveal that the specimen produced by water glass and straw, without binder, has the highest values of hygric properties and thermal insulation.
28
Talvik, Martin, Simo Ilomets, Paul Klõšeiko, Targo Kalamees, Mattias Põldaru, and Dariusz Heim. "Hygrothermal Performance of Thick PCM Mortar behind PV Panels in Energy-Activated ETICS Facades." Buildings 13, no. 6 (June 20, 2023): 1572. http://dx.doi.org/10.3390/buildings13061572.
Abstract:
The concept of integrating PV panels into traditional ETICS facades has been developing for several years. Problems concerning the options for passively controlling the temperatures of PV panels with PCM and directing excess moisture out of the wall via diffusion channels have been previously studied theoretically. During this study, real wall-scale experiments were conducted to test the thermal and hygrothermal performance of the wall system in an extreme climatic environment, as well as in a real outdoor environment in Tallinn, Estonia. Finally, a simulation model was calibrated according to the measured data. It was found that in case of test walls with diffusion channels, it was possible to keep the moisture content of PCM mortar under 0.11 m3/m3. Excess water drained out via channels leading to the external environment. Without diffusion channels, the moisture content rose as high as 0.18 m3/m3. Both the experiments and hygrothermal modelling showed that the high moisture content of PCM mortar, caused by water leakage, dropped to 0.08 m3/m3 over 10 solar cycles as moisture escaped via the diffusion channels. PCM mortar with a moisture content of 0.08 m3/m3 endured extreme rain and freeze-thaw cycles without visual damage, and PV panels retained their electrical production capabilities.
29
Bajzecerová, Viktória, Eva Kormaníková, and Ján Kanócz. "Hygrothermal performance of timber-concrete composite panels – theoretical investigation." MATEC Web of Conferences 310 (2020): 00038. http://dx.doi.org/10.1051/matecconf/202031000038.
Abstract:
The concrete layer as a part of the timber-concrete composite (TCC) element makes it possible to maintain the accumulated heat and thus reduce the energy required for heating. Especially for buildings used for a sauna, swimming pools or wellness. In the TCC cross-section due to uneven thermal and humidity deformation of both materials, additional stresses occur. It can lead to the failure of partial cross-sections or composite connection. The aim of the research is to investigate the influence of changing humidity and temperature conditions of the environment on the composite adhesively bonded TCC panels without the influence of other phenomena such as mechanical stress or the effect of concrete shrinkage. The paper presents the results of the preliminary theoretical investigation before the realization of measurements on prepared specimens.
30
Freimanis, Ritvars, Ruta Vanaga, Viesturs Balodis, Zigmars Zundans, and Andra Blumberga. "Hygrothermal Assessment of Insulation Systems for Internal Insulation of Solid Masonry Walls under Various Conditions." Buildings 13, no. 10 (October 3, 2023): 2511. http://dx.doi.org/10.3390/buildings13102511.
Abstract:
Energy efficiency renovation of building stock is an essential aspect of the climate change mitigation strategies in many countries. A large proportion of building stock is historical buildings. For this building stock, developing technology for safe internal insulation of external walls is crucial, preventing possible moisture damage to the building structures. Internal insulation is a risky technique as it has a high impact on the hygrothermal behavior of the wall. This study assesses the hygrothermal performance of massive masonry walls with 17 interior insulation systems exposed to different external boundary conditions, including a steady-state cycle, dynamic dry cycle, wind-driven cycle, and drying cycle. During the steady state cycle, the highest increase of moisture was observed under capillary active materials ranging from 39 to 119% increase in absolute moisture, with the exception of cellulose with an increase of only 7%. All the vapor-tight insulation systems showed no increase in absolute moisture during the steady-state cycle, with the exception being mineral wool in combination with a vapor barrier that showed a 30% increase in ablute humidity. In addition, relative moisture changes in masonry were measured. Results show that tested insulation systems exhibit similar thermal performance while having different moisture performance. Vapor-tight and vapor-open insulation systems exhibit different hygrothermal behavior under various test cycles depending on material vapor diffusion resistance. Numerical simulations are sensitive to the hygrothermal properties of materials.
31
Giada, Giuffrida, Rosa Caponetto, and Francesco Nocera. "Hygrothermal Properties of Raw Earth Materials: A Literature Review." Sustainability 11, no. 19 (September 27, 2019): 5342. http://dx.doi.org/10.3390/su11195342.
Abstract:
Raw earth historic and contemporary architectures are renowned for their good environmental properties of recyclability and low embodied energy along the production process. Earth massive walls are universally known to be able to regulate indoor thermal and hygroscopic conditions containing energy consumptions, creating comfortable interior spaces with a low carbon footprint. Therefore, earth buildings are de facto green buildings. As a result of this, some earthen technologies have been rediscovered and implemented to be adapted to the contemporary building production sector. Nevertheless, the diffusion of contemporary earthen architecture is decelerated by the lack of broadly accepted standards on its anti-seismic and thermal performance. Indeed, the former issue has been solved using high-tensile materials inside the walls or surface reinforcements on their sides to improve their flexural strength. The latter issue is related to the penalization of earth walls thermal behavior in current regulations, which tent to evaluate only the steady-state performance of building components, neglecting the benefit of heat storage and hygrothermal buffering effect provided by massive and porous envelopes as raw earth ones. In this paper, we show the results of a paper review concerning the hygrothermal performance of earthen materials for contemporary housing: great attention is given to the base materials which are used (inorganic soils, natural fibers, and mineral or recycled aggregates, chemical stabilizers), manufacturing procedures (when described), performed tests and final performances. Different earth techniques (adobe, cob, extruded bricks, rammed earth, compressed earth blocks, light earth) have been considered in order to highlight that earth material can act both as a conductive and insulating meterial depending on how it is implemented, adapting to several climate contests. The paper aims to summarize current progress in the improvement of thermal performance of raw earth traditional mixes, discuss the suitability of existing measurement protocols for hygroscopic and natural materials and provide guidance for further researches.
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Nasr, Yara, Henri El Zakhem, Ameur El Amine Hamami, Makram El Bachawati, and Rafik Belarbi. "Comprehensive Review of Innovative Materials for Sustainable Buildings’ Energy Performance." Energies 16, no. 21 (November 3, 2023): 7440. http://dx.doi.org/10.3390/en16217440.
Abstract:
The building sector, one of the most energy-consuming, is among the most current topics due to the maturing concerns about the anthropogenic factor’s impact on CO2 quantities in the atmosphere and its association with global temperature rise. Using sustainable building materials is a promising alternative in building envelope applications to improve in-use energy efficiency. These materials, having a low environmental impact, the advantage of being renewable, and low embodied energy, contribute to global sustainability. This comprehensive literature review presents a broad overview of these materials’ hygrothermal characteristics, thermal performance, and energy use. The main goal is to compile the most important research findings on these materials’ capabilities for building construction and their contributions and effects on energy performance and thermal insulation.
33
Cacabelos-Reyes, Antón, José Luis López-González, Arturo González-Gil, Lara Febrero-Garrido, Pablo Eguía-Oller, and Enrique Granada-Álvarez. "Assessing the Energy Demand Reduction in a Surgical Suite by Optimizing the HVAC Operation During Off-Use Periods." Applied Sciences 10, no. 7 (March 25, 2020): 2233. http://dx.doi.org/10.3390/app10072233.
Abstract:
Hospital surgical suites are high consumers of energy due to the strict indoor air quality (IAQ) conditions. However, by varying the ventilation strategies, the potential for energy savings is great, particularly during periods without activity. In addition, there is no international consensus on the ventilation and hygrothermal requirements for surgical areas. In this work, a dynamic energy model of a surgical suite of a Spanish hospital is developed. This energy model is calibrated and validated with experimental data collected during real operation. The model is used to simulate the yearly energy performance of the surgical suite under different ventilation scenarios. The common issue in the studied ventilation strategies is that the hygrothermal conditions ranges are extended during off-use hours. The maximum savings obtained are around 70% of the energy demand without compromising the safety and health of patients and medical staff, as the study complies with current heating, ventilation and air conditioning (HVAC) regulations.
34
Hansen, Thor, Eva Møller, and Ruut Peuhkuri. "Towards moisture safe ventilated cold attics – Monitored conditions in a full-scale test building." E3S Web of Conferences 172 (2020): 23003. http://dx.doi.org/10.1051/e3sconf/202017223003.
Abstract:
Existing building stock in Europe accounts for approx. 40% of the total energy consumption. Upgrading the thermal insulation of the existing buildings is an important measure to reduce heat losses through the building envelope. In some cases, increasing the thermal resistance of the construction may compromise the hygrothermal performance of the retrofitted construction. In particular, if vapour barrier is necessary for the good performance and it is practically difficult, if not even impossible, to install a well-sealed air- and vapour tight layer. To investigate the robustness of the hygrothermal performance of ventilated cold attics – with or without a vapour barrier – a monitoring campaign in a full-scale test building was set up. Also role of number of other parameters like moisture buffering capacity of the insulation material and thermal resistance was investigated. This paper presents part of this measuring campaign, which includes conditions both in the attic space and inside the insulation layer. The monitored data covers a period with two winters. The results show that it in temperate climate is practically indifferent for the hygrothermal performance of the monitored, well-ventilated attics with air-tight ceilings whether there is a vapour barrier or not and if the insulation material has moisture buffering capacity or not.
35
Boukhelf, Fouad, Abdelkrim Trabelsi, Rafik Belarbi, and Mohamed Bachir Bouiadjra. "Experimental and numerical modelling of hygrothermal transfer: Application on building energy performance." Energy and Buildings 254 (January 2022): 111633. http://dx.doi.org/10.1016/j.enbuild.2021.111633.
36
Martín-Garín, Alexander, José Antonio Millán-García, Jon Terés-Zubiaga, Xabat Oregi, Iñigo Rodríguez-Vidal, and Abderrahmane Baïri. "Improving Energy Performance of Historic Buildings through Hygrothermal Assessment of the Envelope." Buildings 11, no. 9 (September 15, 2021): 410. http://dx.doi.org/10.3390/buildings11090410.
Abstract:
The intervention on historic buildings through building energy retrofitting has become one of the current challenges of improving energy efficiency. Nonetheless, this building typology presents certain complexities. Among them, one of the most relevant is the protection on their façades due to the historical and/or artistic values of a given façade and, therefore, the addition of external thermal insulation is restricted. However, at the same time, in several of those buildings indoor surfaces do not present that architectural value, and then internal thermal insulation becomes a promising strategy for improving their thermal performance. Nevertheless, its application must be carefully evaluated to avoid possible pathologies caused by moisture problems. This paper aims to identify constructive solutions for interior insulation of walls free from moisture problems. For this purpose, a comprehensive analysis of a series of constructive solutions based on internal insulation has been carried out through hygrothermal simulations. The results show how the application of water-repellent impregnation becomes essential to guaranteeing the integrity of the envelope. In addition, the combination of insulations with or without inner membranes, such as smart vapor retarders or vapor diffusion barriers, has been evaluated detecting the solutions that best fit the objective. Finally, taking advantage of the great potential of 2D simulation tools, the post-processing of the data has been performed to apply the wood decay model, and thus assess the behavior of a very conflictive point in this type of intervention, i.e., the wooden beam-ends. The results in this critical point have shown how the application of the proposed constructive solutions becomes essential to guarantee the integrity of the element and how the application of traditional solutions could lead to a hazard that must be avoided.
37
Freire, Roberto Z., Gustavo H. C. Oliveira, and Nathan Mendes. "Development of regression equations for predicting energy and hygrothermal performance of buildings." Energy and Buildings 40, no. 5 (January 2008): 810–20. http://dx.doi.org/10.1016/j.enbuild.2007.05.014.
38
Pihelo, Peep, Kalle Kuusk, and Targo Kalamees. "Development and Performance Assessment of Prefabricated Insulation Elements for Deep Energy Renovation of Apartment Buildings." Energies 13, no. 7 (April 3, 2020): 1709. http://dx.doi.org/10.3390/en13071709.
Abstract:
A need for the refurbishment and renewal of the existing building stock has been in focus for many decades, principally because of excessive global energy consumption and pollution. This paper presents a methodology and the results of analysis of choices of realizable sets of timber frame prefabricated insulation elements for major renovation of apartment buildings. Numerous combinations of elements with different characteristics were analyzed by applying measurements, interviews, and building performance simulation software, and thereupon their performance, installation eligibility, and concurrent cost levels were compared. Mineral wool board with a special wind barrier facing was found to be the best material as a wind barrier from the perspective of hygrothermal performance. An air and vapor barrier should have sufficient vapor permeability to allow dry-out of constructional moisture. It is possible to renovate apartment buildings to meet the nZEB energy performance requirements and their moisture safety can be guaranteed without paying high relative difference cost. Calculations showed that the global cost was lower for solutions with some mold growth risk. Great care is needed when decreasing costs without simultaneous hygrothermal analyses. The facade cladding was found to have the highest influence on the initial cost of the prefabricated insulation element.
39
Li, Shuangshuang, and Jianping Lin. "Method and Mechanism for Adhesion Recovery of Laser-Treated Aluminum Surface Exposed to Hygrothermal Environment." Journal of Physics: Conference Series 2437, no. 1 (January 1, 2023): 012059. http://dx.doi.org/10.1088/1742-6596/2437/1/012059.
Abstract:
Abstract Laser treatment is used to improve the surface adhesion performance of metal materials, including aluminum alloy. However, the adhesion performance of laser-treated aluminum alloy is reduced after the hygrothermal exposure during storage before bonding, obtaining the reliable surface adhesion is a challenge. In this paper, the nanosecond laser-treated aluminum alloy was exposed in a hygrothermal environment with 80°C 95%R.H. for 48h. Scanning electron microscopy, transmission electron microscopy and adhesion strength testing were used to characterize the physical/chemical properties and adhesion reduction of the aluminum surface. Subsequently, a simple and effective method of heat treatment was proposed to recover the adhesion strength. Finally, molecular dynamics (MD) simulation was utilized to explore the underlying recover mechanism. The experimental results revealed a AlOOH layer with ~410 nm thickness was generated on the laser-treated aluminum surface after hygrothermal exposure, which reduced the adhesion strength by 38% (from 30.9MPa to 18.9MPa). After heating at 120 °C for 24 hours, the adhesion strength (30.4MPa) of aluminum surface recovered to the level before hygrothermal exposure. MD results suggested that there are two mechanisms for the adhesion recovery by heat treatment: 1) the atomic kinetic energy of AlOOH increased and the structural order decreased, which strengthened its electrostatic and hydrogen bond interactions with adhesive molecules; 2) the mechanical property of AlOOH were enhanced.
40
Soulios, Vasilis, Ernst Jan de Place Hansen, and Ruut Peuhkuri. "Hygrothermal simulation assessment of internal insulation systems for retrofitting a historic Danish building." MATEC Web of Conferences 282 (2019): 02049. http://dx.doi.org/10.1051/matecconf/201928202049.
Abstract:
The built environment is accountable for 1/3 of the European energy consumption. Thermal insulation is a key factor affecting the energy performance of buildings. Historic buildings typically were made with solid external walls of brick masonry or natural stone, rarely insulated afterwards. Often the buildings have worth-preserving façades making internal insulation the only feasible technique, however significantly modifying the hygrothermal performance of the façade. The research objective of this paper is to simulate the hygrothermal performance of solid masonry walls in an old Danish hospital that will be internally insulated following the Danish requirement (U-value) for external walls (change of use of buildings) and transformed into dwellings, involving different insulation systems. Heat loss and masonry moisture content level after adding internal insulation and the possible effects of hydrophobization on the moisture content is simulated. Simulations show an increased moisture content in the original wall when adding internal insulation implying an increased risk for moisture-related damage (mould growth, frost damage and interstitial condensation). The results also show that hydrophobic impregnation of the internally insulated facades may be vital in avoiding moisture problems and securing a moisture-safe energy renovation of buildings like the one studied.
41
Pihelo, Peep, and Targo Kalamees. "Development of prefabricated insulation elements for buildings with aerated autoclaved concrete walls." E3S Web of Conferences 172 (2020): 18001. http://dx.doi.org/10.1051/e3sconf/202017218001.
Abstract:
An extensive need for the refurbishment and renewal of existing building stock has been the focus of consideration for many decades, principally because of the high global energy consumption and pollution levels. This paper presents the results of the analysis of certain sets of timber frame prefabricated insulation elements for the major renovation of an apartment building. The hygrothermal measurements were taken, and a series of combinations with elements were analysed using building performance simulation software to compare the main hygrothermal properties. The critical initial moisture content for the surface section of the aerated autoclaved concrete (AAC) panel is w = 65 kg/m3 at a depth of 15 mm and w = 39 kg/m3 at a depth of 70 mm. The results showed that before the design and installation of insulation elements, thorough hygrothermal analysis of the original external envelope, with actual climatic conditions and moisture loads, must be realized.
42
Conley, B., M. Carver, and S. Brideau. "Hygrothermal Monitoring of Two Pilot Prefabricated Exterior Energy Retrofit Panel Designs." Journal of Physics: Conference Series 2069, no. 1 (November 1, 2021): 012028. http://dx.doi.org/10.1088/1742-6596/2069/1/012028.
Abstract:
Abstract NRCan undertook a proof-of-concept project to retrofit a small building with prefabricated wall panels in 2017 in Ottawa, Canada. The retrofit used two wall panel designs: nailbase and woodframe. The Nailbase panel consisted of fiberglass batt, an expanded polystyrene (EPS) core, oriented strand board (OSB) sheathing, a rainscreen, and cladding. The Woodframe panel also featured OSB sheathing and included a 90 mm stand-off gap filled with dense-packed, fibrous insulation. A side-by-side comparison of cost, constructability, and performance was performed. The wall assemblies were instrumented to monitor the temperature, relative humidity, and moisture content of sensitive layers. The data was used to evaluate the hygrothermal performance, moisture accumulation, and risk of associated problems such as mould growth. This paper presents the monitored hygrothermal data from 2017 to 2021, compares the two approaches and assesses their feasibility. During construction, some of the fibrous insulation may have been wetted by wind-driven snow before completion. The data showed that this moisture was able to dissipate without significant risk. The sheathing of the Woodframe panel experienced a higher peak moisture content during the dry-out period. Otherwise, both panel designs showed limited potential for mould growth on monitored surfaces over the monitored period.
43
Kim, Sughwan, Daniel Zirkelbach, and Hartwig M. Künzel. "Review of Methods to Create Meteorological Data Suitable for Moisture Control Design by Hygrothermal Building Envelope Simulation." Energies 16, no. 7 (April 6, 2023): 3271. http://dx.doi.org/10.3390/en16073271.
Abstract:
Hygrothermal simulations have become essential for sustainable and resilient building design because moisture is the major cause of problems in buildings. Appropriate meteorological input data are important to obtain meaningful simulation results. Therefore, this article reviews different methods to create Hygrothermal Reference Years (HRY) as severe or average climate inputs. The current standards define HRYs solely based on outdoor temperature, although moisture problems are caused by a combination of climate parameters, including driving rain and other loads. Therefore, there are also methods considering several impact parameters. The existing methods can be classified into two categories: construction-independent and construction-dependent methods. The former determines HRY based on a weather data analysis and is useful for large-scale parametric studies comprising many climatic parameters acting on buildings. The latter is based in addition to computer simulations to verify the HRY also in the context of specific construction types. It is a more comprehensive approach since the moisture responses of constructions are the decisive outcome for performance predictions. The advantages and disadvantages of the different methods are summarized and compared. Lastly, further research questions and simplifications aimed at practitioners are pointed out to arrive at reliable hygrothermal building performance predictions.
44
Ishikawa, Kazuki, Chiemi Iba, Daisuke Ogura, Shuichi Hokoi, and Misao Yokoyama. "Hygrothermal Analysis of a Museum Storage Room for Metal Cultural Artifacts: Quantification of Factors Influencing High Humidity." Energies 14, no. 11 (June 4, 2021): 3309. http://dx.doi.org/10.3390/en14113309.
Abstract:
Several methods for appropriate control of the hygrothermal environment in museums to prevent the deterioration of cultural artifacts were presented in previous studies. However, few detailed hygrothermal simulation models have been used considering the hygrothermal performance of building components and airflow through gaps. Furthermore, hygrothermal properties of a type of storage facility with buffer spaces prevailing in Japan have not been quantitatively evaluated. The objectives of this study were to develop a detailed numerical model of a museum storage room with buffer spaces exhibiting high humidity during summer and to quantitatively evaluate the potential factors causing it; the inflow of humid outdoor air and indirect cooling caused by the air-conditioning system of a surrounding room. We analyzed the simulated temperature and humidity for various cases in which each influencing factor was suppressed. The humidity was reduced when the exhaust fan for the surrounding rooms was stopped or the windows were made airtight, but it hardly changed when the cooling ducts and the reinforced concrete beams were insulated. Thus, the high humidity in the room was attributed to the inflow of humid outdoor air accelerated by the ventilation of surrounding rooms. Although indirect cooling had a small impact on high humidity, its impact on energy loss could still be significant.
45
Palani, Hevar, Hamed Khaleghi, Parisa Salehi, and Aslihan Karatas. "Assessing Hygrothermal Performance in Building Walls Engineered for Extreme Cold Climate Environments." Sustainability 15, no. 24 (December 6, 2023): 16597. http://dx.doi.org/10.3390/su152416597.
Abstract:
Buildings located in extreme cold climates encounter challenges (e.g., heat loss, condensation, and frozen utilities), especially within their wall envelopes. These challenges also play a pivotal role in occupant health, comfort, and the structural integrity of the building. While the existing literature has primarily focused on thermal performance, this study underscores the importance of evaluating hygrothermal performance within wall envelopes, given the existence of mold growth even in cases of high thermal resistance. Therefore, the aim of this study was to evaluate the hygrothermal performance of an adaptable house wall (AHW) panel that incorporates composite infill panels paired with vacuum-insulated panels to endure harsh cold conditions in Alaska. Therefore, three steps were proposed to: (1) collect the material and thermal properties of the AHW; (2) model the hygrothermal performance of the AHW in WUFI® PRO v6.7 software; and (3) analyze the results. The results revealed a moderate risk of mold growth in the inner plywood layer of the AHW, whereas the outer plywood layer showed zero risk, indicating an acceptable condition. The findings aid decisionmakers in recognizing potential mold-related issues in building walls before advancing to the construction phase.
46
Skagseth, Vegard A., Erlend Andenæs, Bjørn Aas, Gabriele Lobaccaro, and Tore Kvande. "Hygrothermal performance of a CLT Ice Sports Arena in a Nordic climate." Journal of Physics: Conference Series 2654, no. 1 (December 1, 2023): 012105. http://dx.doi.org/10.1088/1742-6596/2654/1/012105.
Abstract:
Abstract Indoor ice sports arenas are complex buildings that typically consume large amounts of energy. The energy is mainly used to freeze the ice rink and to keep the indoor air temperature and relative humidity at appropriate levels. Reducing the energy consumption and the carbon footprint from construction, operation, and material use, presents certain challenges from a building physics point of view. These challenges are especially prominent if the ice sports arena is operated in a climate featuring summer seasons that are warmer than the indoor air temperature and winter seasons that are colder. This study investigates the hygrothermal performance of an ice sports arena built using cross-laminated timber (CLT), located in Sandefjord, Norway. Hygrothermal simulations of the exterior wall were conducted and analysed using WUFI. Locally retrieved weather data is compared to WUFI simulations done in the design process, which were based on Moisture Design Reference Year (MDRY) files for Oslo. The moisture performance of the wall as built is investigated for three different indoor temperatures. Modifications to the wall to improve moisture performance are also investigated. Results indicate that the MDRY files do not accurately reflect the climate on site. The performance of the wall assembly is found to depend greatly on indoor temperature. For indoor temperatures colder than 12 °C, substantial condensation and moisture problems are predicted during summer. None of the investigated modifications are found to sufficiently increase the moisture performance of the wall. Drastic measures may be required to improve moisture safety.
47
Mohammed, Mohammed Alhaji, Ismail M. Budaiwi, Mohammed A. Al-Osta, and Adel A. Abdou. "Thermo-Environmental Performance of Modular Building Envelope Panel Technologies: A Focused Review." Buildings 14, no. 4 (March 27, 2024): 917. http://dx.doi.org/10.3390/buildings14040917.
Abstract:
Modular construction is becoming famous for buildings because it allows a high degree of prefabrication, with individual modules easily transported and installed. Building envelope optimization is vital as it protects buildings from undesirable external environments by expressly preventing the incursion of outside elements. This research uses a systematic literature review to appraise the characteristics of modular envelope panels, focusing on hygrothermal and energy performance. A total of 265 articles were subjected to rigorous filtering and screening measures. The findings reveal notable inconsistencies in modular envelope terminologies and a lack of consistent performance measures, which present significant challenges for research and development efforts. Furthermore, the results indicate a predominant focus on hygrothermal and energy performance in existing studies, with limited attention to environmental impacts and other performance factors. Moreover, the existing literature primarily addresses modular envelope solutions in temperate climates, offering inadequate information for hot and hot–humid climate contexts. To address these gaps, this study proposes categorizing modular envelope panels into four distinct categories: active, passive, smart, and green/vegetated wall panels. These findings will benefit researchers, architects, building envelope designers, policymakers, and organizations developing building performance-related assessment ratings, standards, and codes. The study suggests adopting the categorization of modular envelope panels provided in this study and developing modular panels suitable for hot and humid climates to fill the existing knowledge gap.
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Pérez-Carramiñana, Carlos, Antonio Maciá-Mateu, Germán Sirvent-García, and Iván Lledó-Llorca. "Study of Natural Ventilation and Solar Control Strategies to Improve Energy Efficiency and Environmental Quality in Glazed Heated Swimming Pools in a Dry Mediterranean Climate." Sustainability 14, no. 14 (July 6, 2022): 8243. http://dx.doi.org/10.3390/su14148243.
Abstract:
This paper studies the energy behavior of several public heated swimming pools with semi-transparent covers located in southeastern Spain with high consumption of their air-conditioning installations. The scientific novelty of the work is to determine the influence of solar radiation on the energy performance of this type of building and to demonstrate that the use of passive systems such as natural ventilation and solar control enhance the energy efficiency in glazed heated swimming pools in a warm semi-arid climate. The methodology used consisted of on-site measurements of current hygrometric behaviour and a study of alternative solutions by simulation of virtual models with improved hygrothermal conditions. In the on-site measurements, thermographic images were used to analyse the thermal envelope and hot-wire probe measurements to determine the temperature distribution and air velocity inside the pool enclosure. For the study of alternative solutions, simulations were carried out, including an analysis of incident solar radiation and different natural ventilation and solar control solutions. The results obtained showed that the current hygrothermal behaviour of the interior spaces does not comply with the regulations on the thermal quality of the indoor environment. The results show that the proposed natural ventilation and solar control solutions substantially improved the hygrothermal properties and energy savings of the pools analysed. This work offers an alternative solution that avoids the implementation of costly air conditioning systems and the energy consumption of installations, promoting more sustainable renovations that contribute to improving the indoor comfort of users with interventions that are compatible with existing buildings.
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Silva, Hugo Entradas, and Fernando M. A. Henriques. "Hygrothermal analysis of historic buildings." Structural Survey 34, no. 1 (April 11, 2016): 12–23. http://dx.doi.org/10.1108/ss-07-2015-0030.
Abstract:
Purpose – The purpose of this paper is to verify the applicability and efficiency of two statistical methods to obtain sustainable targets of temperature and relative humidity in historic buildings located in temperate climates. Design/methodology/approach – The data recorded along one year in a non-heated historic building in Lisbon (Portugal) was analysed with the two methodologies, EN 15757 and FCT-UNL. To evaluate their adequacy it was calculated the performance index for each target and it was verified the mechanical and biological degradation risks. Findings – While the use of the two approaches is suitable for temperate climates, there is a higher efficiency of the FCT-UNL methodology, allowing a better response for the three parameters in evaluation. Research limitations/implications – Despite the better results obtained, the FCT-UNL methodology was only tested for one city; therefore the application to other situations may be required to obtain more robust conclusions. Practical implications – The effectiveness of the FCT-UNL methodology to obtain sustainable climate targets can lead to important energy conservation in historic buildings and to contribute for the change of old approaches in the preventive conservation area. Originality/value – This paper provides a comparison between two recent methods. The results can lead to some advances in the science of preventive conservation, interesting to conservators and building physic scientists.
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Biseniece, Edite, Ritvars Freimanis, Reinis Purvins, Armands Gravelsins, Aivars Pumpurs, and Andra Blumberga. "Study of Hygrothermal Processes in External Walls with Internal Insulation." Environmental and Climate Technologies 22, no. 1 (March 27, 2018): 22–41. http://dx.doi.org/10.1515/rtuect-2018-0002.
Abstract:
Abstract Being an important contributor to the final energy consumption, historic buildings built before 1945 have high specific heating energy consumption compared to current energy standards and norms. However, they often cannot be insulated from the outside due to their heritage and culture value. Internal insulation is an alternative. However internal insulation faces challenges related to hygrothermal behaviour leading to mold growth, freezing, deterioration and other risks. The goal of this research is to link hygrothermal simulation results with experimental results for internally insulated historic brick masonry to assess correlation between simulated and measured data as well as the most influential parameters. The study is carried out by both a mathematical simulation tool and laboratory tests of historic masonry with internal insulation with four insulation materials (mineral wool, EPS, wood fiber and granulated aerogel) in a cold climate (average 4000 heating degree days). We found disparity between measured and simulated hygrothermal performance of studied constructions due to differences in material parameters and initial conditions of materials. The latter plays a more important role than material parameters. Under a steady state of conditions, the condensate tolerating system varies between 72.7 % and 80.5 % relative humidity, but in condensate limiting systems relative humidity variates between 73.3 % and 82.3 %. The temperature between the masonry wall and all insulation materials has stabilized on average at +10 °C. Mold corresponding to Mold index 3 was discovered on wood fiber mat.