bluuebunny/crossref_metadata_2025 huggingface dataset:
Circular building design: a case study in Pakistan
Authors: Talpur B D , Rubino C , Liuzzi S , Martellotta F
Published: December 2023

A major transformation from the current, linear practice to a closed-loop system, linked with a circular economy, is required to transform the negative effects of buildings on the environment. Pakistan has one of the fastest growing populations, and conventional building construction is increasing in urban areas due to urban sprawl. This research aims to demonstrate the possible shift to a circular construction industry in Pakistan by comparing the linear design components with the circular design components of exterior walls of a case study taking advantage of life cycle assessment. The results of life cycle assessment applied to the external walls of a house in Karachi show that finding the solution with the lowest impacts is not obvious and that use of apparently “green” solutions may turn out to have higher impacts. Study suggests that building components can be gradually replaced with more circular ones to create a circular built environment.
From certificate to physics - Paths to net-zero compatible buildings
Authors: Bagemihl J , Jakob M , Frost S Banfi , Sprecher F
Published: December 2023

The role of heat pumps in a decarbonised (thermal) energy system is pivotal. This technology is often in competition with other technologies such as district heating or boilers. When comparing different heating technologies in respect to their CO2 footprint and their costs, the calculation method of future greenhouse gas emission factors of the different energy carriers and energy prices is decisive. Emission factors need to be based on technical and physical fundamentals as (international) green certificates are not a satisfactory proxy for physical emissions, especially for the case of electricity. Currently the Swiss electricity generation system is mostly decarbonised with its high share of hydropower and nuclear energy. However, Switzerland, located in the heart of Europe, has the highest relative shares of cross border capacities, which are relevant for energy trading. In a still fossil dominated European power system, the high volatility of wholesale power prices is entailing a high (temporal) volatility of power related emissions. Thus, the overall carbon footprint of consumed electricity changes significantly over time. Heating demand also shows a dynamic behaviour. It is therefore likely, that a CO2 footprint based on annual averages in heating demand and emission factors could lead to significant errors. The aim of the research was to draw a comparison of the resulting annual CO2 emissions applying different time step aggregation levels (yearly, monthly, typical days) with the results calculated based on a complete year in hourly resolution. The aim was to determine the relative error made through aggregation.
Thermal performance of residential and non-residential sectors: describing differences and understanding underlying reasons
Authors: Sasso Francesco , Patel Martin K
Published: December 2023

This paper presents a comparative analysis of thermal performance and heating demand for selected residential (single-family houses, SFHs and multi-family houses, MFHs) and non-residential sectors (Offices and Schools). The thermal performance and space heating demand of the Swiss building stock were analysed by a bottom-up element-based archetypal model. SFHs are characterised by the best envelope thermal performance (average envelope U-value = 0.62 W/(m2K)), followed by MFH (0.73 W/(m2K)), Schools (0.75 W/(m2K)), and Offices (0.84 W/(m2K). Results show significant differences regarding architectural features between building sectors: SFHs are characterised by the highest envelope factor (median value = 2.00), defined as the ratio between external surfaces and heated area, followed by Schools (1.50), MFH (1.30), and Offices (1.25). As a consequence of the above-mentioned differences, SFHs show higher specific final energy demand for space heating (on average 148 kWh/(m2year)), followed by Schools (117 kWh/(m2year)), Offices (100 kWh/(m2year)), and MFH (93 kWh/(m2year)). Moreover, a high potential for decarbonisation of heating systems in the Swiss building stock was identified: more than 70% of the ERA is heated by fossil fuel-based heating systems, with some differences amongst the studied sectors. This analysis serves as an important starting point to examine possible retrofit pathways and policies across sectors.
A new heat and cold storage system to enhance the thermal autonomy of residential buildings
Authors: Robadey J , Richard R
Published: December 2023

We integrated 18 kg of PCM in 80 cells of a plate heat exchanger which were placed between a water charge and an air discharge circuit fed by the air renewal. The 0.1 m3 thermal battery can replace radiators to heat and cool, store heat and cold and perform air renewal independently for each room. The narrow PCM cells and the relatively large temperature difference between the PCM with fusion temperature of 25°C and the renewed air allowed to achieve average discharge powers of 300W and 440W for heating and cooling respectively. The integrated total heat and cold storage capacities were found to be 1.5 kWh and 1.8 kWh respectively. By replacing each radiator of a house with such a battery substantial thermal storage can be achieved. The liquid thermal battery, cooled with outdoor air of 17°C, completely solidified in less than 7h. This means that cool summer nights can charge the PCM to cool the room the following day.
Potential-estimation of thermal micro-grids in urban areas based on heat load and building clustering
Authors: Hall Monika , Bereuter Pia , Geissler Achim
Published: December 2023

As a result of climate change, fossil heating systems must be replaced with renewable systems. The question arises whether it makes sense for each building to have its own new heating system or whether a thermal micro-grid is possible. In this paper a model is presented which allows to aggregate buildings into thermal micro-grid clusters. All gas-heated residential buildings of Basel (Switzerland) are marked via geo-data. The heat demand of each building is determined depending on the year of construction and is then converted into the heat load. Each building then is grouped into thermal micro-grids according to a given grid load limit. The thermal micro-grids generated in this way are marked in color, so that the potential of any given city district can be easily and quickly identified. If the grid load limit is increased, the number of possible micro-grids increases, also.
Heat pumps on exhaust air for space heating and domestic hot water, in very high energy performance multifamily building (Geneva, Switzerland): feedback in actual condition of use
Authors: Callegari S , Hollmuller P
Published: December 2023

This paper, which is based on a monitored case study, analyses the issues and potential of heat recovery on exhaust air in new multi-family buildings, for combined DHW and SH production by way of heat pumps, in combination with a gas boiler for peak loads. Analysis of the hydraulic diagram, as well as readings of heat and energy meters, allows to point out the causes of an actual HP share (38%) much lower than the projected value (61%), while bringing up the necessity to elaborate standard schemes and sizing rules for such systems.
Applicability of a heat-pump-driven liquid-desiccant air-conditioning system in energy-efficient buildings
Authors: Lee J H , Kim B J , Joung J W , Jeong J W
Published: December 2023

Building trend is toward energy-efficiency by reducing building sensible load, while neglecting latent load. A heat-pump-driven liquid-desiccant (HPLD) air-conditioning system has emerged for effectively handling building latent load in energy-efficient buildings with low indoor sensible heat ratio. However, previous studies only investigated one building type, failing to account for the increase in building energy-efficiency. This study estimates building thermal loads of four different energy-efficient high latent load buildings, simulating building trend. Then, as energy-efficiency of buildings increases, the changes in indoor thermal comfort and energy consumption of the HPLD air-conditioning system and reference vapour compression system are compared. Simulation results show that in building with the highest energy-efficiency, the reference system can only maintain thermal comfort for 43.3% and 24% of summer operating hours when primarily meeting supply-air target temperature and humidity, respectively. Contrastingly, the proposed system can maintain thermal comfort in all building types for almost 100% of summer operating hours due to decoupled control of air temperature and humidity. Additionally, the proposed system saves up to 33.2% of operating energy when both systems achieve the same thermal comfort satisfaction. In conclusion, the HPLD air-conditioning system with decoupled control is more applicable as energy-efficiency of buildings increases.
The Building Data Genome Directory – An open, comprehensive data sharing platform for building performance research
Authors: Jin Xiaoyu , Fu Chun , Kazmi Hussain , Balint Atilla , Canaydin Ada , Quintana Matias , Biljecki Filip , Xiao Fu , Miller Clayton
Published: December 2023

The building sector plays a crucial role in the worldwide decarbonization effort, accounting for significant portions of energy consumption and environmental effects. However, the scarcity of open data sources is a continuous challenge for built environment researchers and practitioners. Although several efforts have been made to consolidate existing open datasets, no database currently offers a comprehensive collection of building data types with all subcategories and time granularities (e.g., year, month, and sub-hour). This paper presents the Building Data Genome Directory, an open data-sharing platform serving as a one-stop shop for the data necessary for vital categories of building energy research. The data directory is an online portal (buildingdatadirectory.org/) that allows filtering and discovering valuable datasets. The directory covers meter, building-level, and aggregated community-level data at the spatial scale and year-to-minute level at the temporal scale. The datasets were consolidated from a comprehensive exploration of sources, including governments, research institutes, and online energy dashboards. The results of this effort include the aggregation of 60 datasets pertaining to building energy ontologies, building energy models, building energy and water data, electric vehicle data, weather data, building information data, text-mining-based research data, image data of buildings, fault detection diagnosis data and occupant data. A crowdsourcing mechanism in the platform allows users to submit datasets they suggest for inclusion by filling out an online form. This directory can fuel research and applications on building energy efficiency, which is an essential step toward addressing the world’s energy and environmental challenges.
Modelling of multi-energy systems of residential buildings with Calliope and validation of results
Authors: Schilt U , Linder E , Meyer M , Schneeberger S , Melillo A , Roos P , Schuetz P
Published: December 2023

Given the current and future importance of energy availability in the residential sector, there is great interest in reducing and optimising the energy consumption of single and multi-family houses. An energy system consisting of solar PV, heat pump, and battery and thermal storage can reduce electricity grid dependence by maximising the use of renewable energy. However, creating a model for such a multi-energy system can be challenging due to the need for detailed input data and high computational cost. This study aimed to develop a simpler model with short computation times and sufficient accuracy by employing a mixed-integer linear programming (MILP) method based on the modelling framework Calliope, allowing the investigation of optimal operation regarding energy consumption and autarky. The results of a model simulation were compared to measurements acquired at a pilot site of a residential building in an alpine region of Switzerland. The results show good agreement between the model and pilot site for PV self-consumption (-5%), grid-export (+3%), and battery usage (-2%), whereas larger discrepancies were observed for the utilisation of the thermal storage (-78%). With the necessary modifications the developed model will be useful in estimating the feasibility and impact of multi-energy systems in residential buildings.
Data-driven modeling of heat pumps and thermal storage units for MPC
Authors: Brandes M , Cai H , Vivian J , Croci L , Heer P , Smith R
Published: December 2023

Heat pumps can play a crucial role in the European energy strategy 2050, which aims to achieve net-zero greenhouse gas emissions. When coupled with thermal energy storage and integrated with advanced control strategies, heat pump operation can be optimized to reduce carbon footprint and respond to the needs of system operators. However, to scale in a multitude of buildings, the transferability of the modeling into heterogeneous systems is crucial. In this paper, two different interpretable linear models, a hybrid (grey-box) and a fully data-driven (black-box) model are investigated. Specifically, two regression-based identification methods (SINDYc and DMDc) are used for dynamic models and the LASSO regression is used for static models. The transferability of the approach is evaluated using two real-world facilities with heterogeneous sizing and configuration. The results show a similar simulation performance for both cases with a maximum normalized RMSE of 0.41 and 0.60, respectively. This confirms the transferability of the approach that is necessary for large-scale implementation.
Energy Performance Certificate Estimation at Large Scale Based on Open Data
Authors: Montet Frédéric , Pongelli Alessandro , Schwab Stefanie , Devaux Mylène , Jusselme Thomas , Hennebert Jean
Published: December 2023

This paper presents an innovative methodology for enhancing energy efficiency assessment procedures in the built environment, with a focus on the Switzerland’s Energy Strategy 2050. The current methodology necessitates intensive expert surveys, leading to substantial time and cost implications. Also, such a process can’t be scaled to a large number of buildings.

Using machine learning techniques, the estimation process is augmented and exploit open data resources. Utilizing a robust dataset exceeding 70’000 energy performance certificates (CECB), the method devises a two-stage ML approach to forecast energy performance. The first phase involves data reconstruction from online repositories, while the second employs a regression algorithm to estimate the energy efficiency.

The proposed approach addresses the limitations of existing machine learning methods by offering finer prediction granularity and incorporating readily available data. The results show a commendable degree of prediction accuracy, particularly for single-family residences. Despite this, the study reveals a demand for further granular data, and underlines privacy concerns associated with such data collection. In summary, this investigation provides a significant contribution to the enhancement of energy efficiency assessment methodologies and policy-making.
Determine the heat demand of existing buildings with machine learning
Authors: Hofmann Joachim Werner , Amoser Christian , Geissler Achim , Hall Monika
Published: December 2023

The renovation rate of existing buildings plays a major role in the Swiss Energy Strategy 2050+. To increase this rate, there must be a simple and cost-effective method to determine the heat demand of existing buildings. In this paper, the generation of such a method, based on the Swiss cantonal building energy certificate (GEAK) database with the help of machine learning (ML), is studied. The aim of the project was to develop a ML model which allows the heat demand of existing buildings to be determined quickly with a minimal set of parameters. The comparison of the GEAK building envelope class for single family houses calculated with the new ML model and the original GEAK classes shows that approximately 62 % have the same class, 32 % differ by one class and 6 % by two classes. The ML model is a good starting point for further refinements and developments.
A Review and Analysis of Energy Systems Planning Models and Tools for Renewable Energy Integration in Cities
Authors: Yazdanie M , Orehounig K
Published: December 2023

This review study evaluates a range of urban energy system planning models/tools (UEPMs) with respect to their capabilities to consider, identify, integrate and scale up renewable energy technology (RET) deployment in cities. Working with local stakeholders, we define twenty weighted evaluation criteria in order to assess UEPM capabilities using a multi-criteria decision analysis approach. We then discuss the top-ranking UEPMs in the context of our aims. We also survey and interview UEPM practitioners and experts in order to gain a better understanding of their needs, challenges and perceived barriers in the field. The outcomes of this work are useful for both UEPM users and researchers in order to improve the uptake and application of UEPMs by decision-makers to develop sustainable energy plans.
Next generation of heat pumps for buildings based on thermoelectricity integrated with smart grids
Authors: Díaz de Garayo S , Ciria R , Fernández M
Published: December 2023

This paper proposes a HVAC system that integrates a novel thermoelectric heat pump with a double flux ventilation system and a sensible heat recovery unit able to provide heating, cooling and ventilation to a 74.3m2 pilot passive house in Pamplona (Spain). The heat pump has been previously prototyped and analysed in the laboratory, showing COPs ranging 1.5-4 for heating and 0.5-2 for cooling. This study investigates the energy performance of the combined system (heat pump and ventilation unit) and the comfort conditions of the dwelling one year long, showing the advantages of this technology and the potential integration with PV based building-level smart-grids.
Development of design calculations for radiant ceiling panels incorporating phase change materials (PCMs)
Authors: Švarcová E , Shinoda J , Bogatu D I , Kazanci O B , Petráš D , Olesen B W
Published: December 2023

Thermally active building systems (TABS) show significant benefits such as providing peak load shifting, peak load reductions, and energy savings. Phase change material (PCM) applications with water circulation have benefits similar to TABS, but PCMs can store more heat per unit volume than concrete due to the latent heat exchange. Radiant panels with PCM can be applied in building retrofit, which gives this application a significant advantage compared to TABS. A design methodology for determining heat flux does not exist though for dimensioning a radiant ceiling system that incorporates PCM. Design methods according to standards for TABS – ISO 11855-2 and for radiant panels – ISO 18566-3 were investigated. Five radiant ceiling panels incorporating PCM were selected from Denmark, Canada, Germany, the Czech Republic and Latvia. The resulting heat flux between the panel and conditioned space, i.e. the room, following methods represented in the standards, were compared with the measured or simulated values reported in the literature. The comparison showed that the calculation for TABS (ISO 11855-2) led to similar results to the measured or simulated values.
Energyplus model of double skin façade and diffuse ceiling ventilation
Authors: Hu Y , Larsen O K , Zhang C , Larsen T S
Published: December 2023

This paper introduces an Energyplus model to combine the double skin façade and diffuse ceiling ventilation systems with weather-adjusted dynamic control for both heating and cooling purposes. The proposed Energyplus model is validated with measurement data for both the heating mode and cooling mode. The double skin façade, diffuse ceiling, and the room are modeled as different thermal zones in Energyplus. The ventilation between the adjacent zones is controlled by zone ventilation and zone mixing. The cooling mode of the double skin façade is modeled by wind and stack. An energy management system (EMS) controls the ventilation modes based on outdoor conditions and indoor air temperature. The geometry of the model is identical to the experiment room in the façade lab facing south, with the same internal load and ventilation mode. The model results are then compared to the experimental data, including both heating mode and cooling mode for 4 thermal zones: The DSF zone, the DSF top zone, the diffuse ceiling zone, and the room zone. For heating mode, the average discrepancy of all 4 thermal zones between the model results and experimental data is 13,75%, while for cooling mode, the average discrepancy is 13.78%. The model performance of the room zone is the highest, which has a discrepancy of 5.31% for the heating mode and 3.67% for the cooling mode compared to the experimental data.
Exergy analysis on the low flow rate of solution in the atomization-based liquid desiccant system
Authors: Lee Soo-Jin , Cheon Seong-Yong , Kim Seheon , Kwon Taek-Don , Jeong Jae-Weon
Published: December 2023

The purpose of this study is to analyse the proposed liquid desiccant absorber with low solution flow rate compared with the conventional packbed-type absorber. The total exergy destruction and exergy efficiency were estimated to assess the system performance. To determine the total exergy destruction and exergy efficiency, it was predicted that the specific thermal and chemical exergy in the inlet and outlet both air and solution side of the absorber. The results indicated that the average total thermal and chemical exergy destruction is 0.054 kW and 0.080 kW in the proposed system while it is 0.292 kW and 0.093 kW in the conventional absorber. The exergy efficiency is 0.573 and 0.114 on average in the proposed and conventional absorber, respectively.
Degradation-aware data-enabled predictive control of energy hubs
Authors: Behrunani Varsha , Zagorowska Marta , Badyn Mathias Hudoba de , Ricca Francesco , Heer Philipp , Lygeros John
Published: December 2023

Mitigating the energy use in buildings, together with satisfaction of comfort requirements are the main objectives of efficient building control systems. Augmenting building energy systems with batteries can improve the energy use of a building, while posing the challenge of considering battery degradation during control operation. We demonstrate the performance of a data-enabled predictive control (DeePC) approach applied to a single multi-zone building and an energy hub comprising an electric heat pump and a battery. In a comparison with a standard rule-based controller, results demonstrate that the performance of DeePC is superior in terms of satisfaction of comfort constraints without increasing grid power consumption. Moreover, DeePC achieved two-fold decrease in battery degradation over one year, as compared to a rule-based controller.
Flexibility assessment of power-hydrogen-power (P2H2P) system in multi-energy districts
Authors: Koirala B P , Cai H , de Koning J , Heer P , Orehounig K
Published: December 2023

Climate change mitigation plans and recent tension over gas supply generate significant incentives for reducing reliance on fossil fuels in the built-environment, with an increase in installing renewables and in electrifying the heating sector. However, the seasonal imbalance of energy supply and demand is expected to increase further. Sector coupling enabled through power-to-hydrogen-to-power (P2H2P) systems that include seasonal storage can partially mitigate this issue. In this work, a hydrogen-based multi-energy system is modelled with a mixed-integer linear programming based Ehub optimization tool. While results show that the P2H2P system is technically and spatially feasible and more flexible, its large hydrogen storage is associated with high costs and embodied carbon emissions. Finally, an outlook for P2H2P systems for integration into renewable-based systems is presented.
Evaluating the capabilities of a simplification algorithm for Urban Building Energy Modeling in performing building-level Multi-Objective Optimizations at district scale
Authors: Battini Federico , Pernigotto Giovanni , Gasparella Andrea
Published: December 2023

Since Urban Building Energy Modeling and Multi-Objective Optimization require large computational resources, both could benefit of simplification techniques able also to make them more affordable to professionals. In this work, the capabilities of a simplification algorithm for urban scale application are assessed in the context of the optimization of energy efficiency measures for buildings. A group of buildings from different districts were selected along with a set of energy efficiency measures and four objectives, such as heating and cooling needs, thermal comfort, and costs. The performance of the simplification was assessed by using precision, recall and F1-score as metrics to check whether the simplified models could obtain the same optimal solutions as the detailed ones. Overall, the simplification produced adequate results with an F1-score greater than 0.8 for 85 % of the cases considered in all climates, allowing the simulation time to be reduced up to 15.7 times.
Development of an early design tool for the sustainability assessment of positive energy districts: methodology, implementation and case-studies
Authors: Brunetti A , Cellura S , Guarino F , Longo S , Mistretta M , Reda F , Rincione R
Published: December 2023

The concept of Positive Energy District is one of the research ideas that embody the ambitions of decarbonization, renovation (both literal and in a wider perspective) and inclusivity for the urban environment portrayed in the EU activities. In this framework, the paper presents a modeling and simulation tool which allows for an early-design depth to be applied in the field of Positive Energy Districts renovation design and integrated performance assessment. The work aims at creating a tool for stakeholders and designers that would allow them to: a) Calculate carbon impacts along the life cycle for different technical systems and materials used for retrofitting; b) Compute use stage carbon emissions, including import-export of electricity; c) Computations of PED carbon emission balances, along the expected useful life of the district computing both embodied and the use stage carbon emissions. The tool has been created as a spreadsheet including typical profiles of energy use per building archetype, with the inclusion of available and free Life Cycle Assessment data within the life cycle carbon assessment and aims at jointly developing use stage and life cycle considerations. It was tested on a district case studies in the EU.
Effect of climate on the optimal sizing and operation of seasonal ice storage systems
Authors: Vivian Jacopo , Heer Philipp , Fiorentini Massimo
Published: December 2023

Seasonal thermal storage systems can reduce the temporal mismatch between renewable energy availability and energy demand. Ice storage systems exhibit a non-linear behaviour in the heat exchange and storage processes, complicating the formulation of optimal design and operation problems. In this work, we propose a mixed-integer quadratically-constrained programming formulation, which minimizes the Levelized Cost of Energy for space heating and cooling, including sizing of a supporting PV array. The optimization was repeated for different storage volumes, finding the system optimal operation in each case –and thereby the optimal system sizing. The heating and cooling demands were computed from an archetypal office building, placed in three reference locations with cold and semi-arid, warm and humid continental, and temperate and humid continental climates. Results show that the optimal PV size decreases with growing ice storage volume, and an ice storage works best in a temperate continental climate, covering up to 47% of the cooling demand with a 250 m
3 storage.
Optihood – a multi-objective analysis and optimization framework for building energy systems at neighborhood scale
Authors: Dimri N , Zenhäusern D , Carbonell D , Jobard X , Jacquot V , François A , Capezzali M , Fesefeld M
Published: December 2023

Strategic planning of future energy systems in a district is essential to fully exploit the benefits from sector coupling. In particular, new solutions may arise when a group of buildings is considered rather than individual buildings. Therefore, in order to identify optimal production and storage technologies within a district, new tools are needed. In this paper we present the open-source software framework optihood, which allows for multi-objective optimization and analysis of energy systems for neighborhoods. The tool assists researchers and, in a future stage, energy planners in the design of energy systems as well as in optimizing their operation strategy. After introducing the tool, its applicability is demonstrated with a case study, wherein we investigated the supply of a small neighborhood of four residential buildings with space heat, domestic hot water and electricity demands. The optimizer was allowed to consider heat pumps (geothermal/air-source), PV, batteries and hot water storage tanks as available technologies. We show comparisons between optimal solutions in terms of total annualized cost for the buildings considered (a) together as a group and (b) individually.
Identifying and monitoring the Urban Heat Island in the compact Mediterranean city using satellite imagery and in-situ measurement data
Authors: Palusci O , Laurino V , Barbieri V , Buccolieri R
Published: December 2023

The combination of the Urban Heat Island (UHI) phenomenon and the increased frequency and intensity of summer heat waves causes increased energy demand and consumption for air cooling and augmented thermal discomfort and heat-related morbidity and mortality in urban areas. This circumstance is particularly problematic in areas where a rise in the mean air temperature can be already observed, like the Mediterranean Basin. Although the UHI effect is a well-known phenomenon, a detailed investigation of the relationship between urban morphology and temperature distributions in actual compact Mediterranean cities needs further investigation. Therefore, the present study is conducted by employing satellite imagery and in-situ measurements to monitor the UHI phenomenon and identify urban hotspots in several cities in Italy. It should be noted that the selected cities differ in latitude, climate, size, altitude, and location, allowing the investigation of the relationship between urban morphologies, air, and surface temperature in different contexts. This paper reports the methodology developed to carry out ongoing research and some preliminary results.
Comparing different approaches to define shading control threshold via a new automatic building simulation platform
Authors: Chiesa G , Grasso P , Fasano F
Published: December 2023

Active shading systems are essential to prevent heat gains in buildings and reduce the risk of overheating phenomena. The control logic must avoid overheating while allowing solar gains during heating hours. In general, smart control is based on a temperature and/or solar irradiation threshold; however, innovative informatics tools now allow optimising these thresholds based on specific building and climate characteristics. The paper presents a new building energy dynamic simulation platform used here to define optimal shading control thresholds for free-running and mechanically cooled spaces. Several shading control approaches are applied and compared, considering fixed hourly schedules, controls based on standard thresholds, and optimised thresholds with the tool. The analysis is performed considering the sole summer. The approach shows how the developed platform and the proposed methodology can optimise shading control thresholds, considering the specific building characteristics and the local climate conditions, consequently reducing energy needs or thermal discomfort conditions.
Examining the climate responsiveness of End-of-life photovoltaic (EoL-PV) integrated buildings
Authors: Rao R R , Mani M
Published: December 2023

Globally, 70-80 million tonnes of EoL-PV waste is expected by 2050. A large fraction of PV waste heading into landfills threatens the environment and human health. On the other hand, the rising need for building materials in developing countries is imminent. A hitherto untried solution is proposed to use EoL-PV panels as a building material to address this issue, and this approach will enable sourcing a low-cost, low-embodied energy building material. This work examines the climate responsiveness of a building adopting EoL-PV as a wall. A prototype building is commissioned, and a simulation model of the same building is created. EoL-PV, due to its lower thermal mass and high thermal transmittance, results in higher variations of temperature and RH. This may imply poor occupant comfort and requires modifications to the EoL-PV panel to be used as a building material, ensuring good thermal performance and occupant comfort.
From near real-time urban data to an explainable city-scale model to help reduce the Urban Heat Island (UHI) effect
Authors: Eslamirad Nasim , Luca Francesco De , Yahia Sadok Ben , Lylykangas Kimmo
Published: December 2023

Urbanization is associated with increasing the temperature of urban areas and phenomena like the Urban Heat Island (UHI). The latter produces a sensible impact on people’s health, quality of life, urban liveability, and even the mortality rate. As a result, reducing high temperatures in cities will improve the quality of life in cities. Overall, the understanding of the relationship between UHI and urban features is not well captured due to a lack of accessibility to data and cost implications related to long-term monitoring and simulation processes. Machine Learning (ML) offers significant opportunities to develop approaches that lead to high accuracy in discovering the significant features of buildings and urban areas, improving the conditions of the inhabitants. The paper aims to describe how the actual spatial data of Tallinn, Estonia, were assessed and applied to build an Explainable ML-based model. The study outcomes include the ML-based models that help understand the importance of urban features and their value in developing strategies and solutions to mitigate the UHI effect. The study’s findings show that changes in the most important features of urban areas and buildings, such as the built area in the neighborhood zone and the area and orientation of buildings, play the most significant role in transforming an urban area from one with no UHI effect to one that experiences heat waves. The results provide essential information for urban planners who implement built environments.
Sequentially coupling LBNL-method and Modelica to model and operate adaptive facades with inhomogeneous printing patterns
Authors: Weber Simon Oskar , Fang Yuan , Park Sumee , Leistner Philip
Published: December 2023

In this work, two U- and g-value Modelica models of a three-layer membrane construction with inhomogeneous stripe pattern were set up. Thus, a simple ISO 52022 model is compared with a detailed model with Modelica integration of Klems-Matrices by LBNL method calculation. For the U-value, both models equally predict the heat transmission. For the g-value, the detailed model shows an strong angular behavior depending on the stripe pattern, the layer distances. Compared to a reference glazing, the application of an adaptive operating strategy results in a reduction of the total energy consumption by up to 27%. Depending on the operation strategy the heating energy increases between 33-100% and cooling energy decreases by 50-80%. This is mainly due to the lower g-value with the detailed model. The actuation energy required for this can be neglected. The resulting reductions in heating and cooling energy exceed the actuation energy by several orders of magnitude.
Impact of different thermal zone data simplification for model calibration on monitored-simulated performance gaps
Authors: Chiesa G , Fasano F , Grasso P
Published: December 2023

The paper analyses the impact of different simplification approaches for model verification purposes considering a reference demo case of a municipality school located in Torre Pellice (Italy), which has been monitored with room detail since April 2021. The target variable of the calibration process is the indoor air temperature: firstly, results validity is checked on an unoccupied free-running period; secondly, occupied standard behaviours and adapted to real-use ones are adopted to test the simplification choices impact on indoor thermal comfort indicators (e.g. the Adaptive Comfort Model). Several model simplification actions on both building-level construction and zoning approaches are considered. Results of this demo case demonstrate the usability of simplified models, which can be adopted instead of more detailed and time-consuming full models for performance gap detections and other analyses.
Green roof energy performance in different climate zones: a simulation study
Authors: Kulumkanov Nursat , Nadeem Abid , Tokbolat Serik
Published: December 2023

Green roofs are widely used as a passive building design technique to decrease the cooling demand in buildings. The vegetation uses the energy of the surroundings during the evapotranspiration process, leading to a temperature decrease in air. This paper investigates the effectiveness of green roofs in 45 cities in different climate zones. The simulation of the energy performance of buildings is performed using DesignBuilder software, which integrates the EnergyPlus engine. The results show that green roofs effectively reduce the cooling load but increase heating energy consumption. The highest performance in total energy savings was in the arid zone with savings ranging from 3.2% to 9.1%, despite having a high heating demand. Tropic and temperate zones show relatively lower results, which vary from 1.4% to 4.1% and -0.2% to 4.2%. The cold zone shows the worst result, ranging by around 1%. Thus, green roofs show better performance in cities with high-temperature ranges, direct radiation, and humidity level.
Experimental characterization and modal analysis for woven composite high aspect ratio beam
Authors: Osama M , Ahmed M Y , Khalil M , Saleh S
Published: December 2023

In modern engineering applications such as aerial vehicles, composite structures are widely implemented due to their high structural stiffness and very low weight-to-lift ratio. They also enable designers to control their mechanical properties as well as the manufacturing method and fabrication quality to achieve the required structural performance. However, various manufacturing methods and the fabrication process can be considered production imperfections. In this study, an assessment of the fabrication quality for a typical composite structure is implemented. As considered for airplane wings and helicopter blades, a high aspect ratio structure is implemented as a case study. This structure is composed of laminated woven carbon fiber/epoxy resin fabricated using the vacuum bagging production method. To characterize the mechanical properties of the proposed structure, a mechanical tensile test is carried out. An experimental modal analysis via roving hammer test is implemented to examine the dynamic behavior of the proposed structure. To assess the quality of manufacturing and fabrication quality, the obtained natural frequencies are compared with the ones computed using a numerical technique using the Finite Element Method (FEM). The analytical problem using MATLAB had been established to emphasize the experimental results. Results showed that good manufacturing quality is achieved by using the vacuum bagging production method. Also, the experimental results agree well with both the numerical and theoretical results, Which indicates good manufacturing quality.
Simulation of tilt-rotor UAV flight dynamics in horizontal flight
Authors: Ibrahim Noureldein A , Zakaria Mohamed Y , Kamal Ashraf M
Published: December 2023

Tilt-rotor unmanned aerial vehicles (UAV) have gained significant importance in the aeronautical industry due to their ability to transition between vertical and horizontal flight. One of the important steps in the development of such UAVs is to assess their performance and stability characteristics. Simulation of flight dynamics is an essential tool that enables the designers to test and optimize the flight characteristics of these UAVs. This paper presents a complete procedure for developing a 6-degree-of-freedom flight dynamics model of a tilt-rotor UAV in fixed-wing mode using a physics-based modeling approach. All necessary sub-models are developed and integrated into the Simulink simulation environment to allow for predicting the UAV’s dynamic response. The developed model is verified for correct operation by simulating horizontal steady-level flight and exciting its natural longitudinal modes.
Experimental investigation of the effects of diesel-bioethanol blends on combustion and emission characteristics in industrial burner
Authors: Elkelawy M , Bastawissi H A , Abdel-Rahman A K , Abou-elyazied A , El-malla S
Published: December 2023

The increased rate of industrialization in various countries has increased the demand for fossil fuels, which are found in limited reserves and in specific countries. As a result, countries that lack these energy resources are experiencing an energy crisis. As a result, alternative fuels that are made locally within countries are needed, like alcohol.. Experiments were carried out in this research to examine the combustion and emission characteristics of diesel and bioethanol blends using an industrial 350 KW burner. Three different diesel/bioethanol ratios (DE-10, DE-15, and DE-25) were tested. Flame geometries, temperatures, and emissions for diesel/bioethanol blends were measured experimentally for each type of fuel to obtain a complete characterization of the combustion processes. The findings showed that an increase in the percentage of bioethanol in the fuel blends for DE-10, DE-15, and DE-25 reduced CO, UH, NOx, and soot emissions (by around 20%, 40%, and 45%), (by about 13%, 25%, and 43%), (by about 8%, 14%, and 22%), and (by about 16%, 33%, and 50%), respectively, compared to neat diesel combustion. However, because bioethanol has a lower heating value than diesel, As bioethanol percentages increased in the fuel mixture, exhaust temperature and maximum flame temperature decreased.
Spacecraft fault detection and identification techniques using artificial intelligence
Authors: Abdel Aziz T S , Salama G I , Mohamed M S , Hussein S
Published: December 2023

The complexity of spacecraft systems and their missions is increasing, requiring higher levels of performance and innovative solutions. It is essential to have onboard autonomy with minimal faults to ensure reliability, availability, and safety. Fault Detection and Identification (FDI) is critical in identifying spacecraft faults before they cause major failures. However, FDI design and application are challenging due to the space environment and the reliance on system information. To improve accuracy, speed, and noise robustness, modern FDI methods based on Artificial Intelligence (AI) techniques have been developed. This paper investigates the latest FDI techniques in the spacecraft attitude determination and control subsystem (ADCS) and electrical power subsystem (EPS). The article discusses various FDI methodologies and frameworks, highlighting their advantages, drawbacks, and the significance of AI implementation. Additionally, the paper presents a thorough analysis and comparison of the different methods.
Modeling and analysis for reaction control thruster used for station-keeping maneuvers of a GEO satellite
Authors: Ashraf M K , Hendy H , Sallam A F , Ashry M M , Elhalwagy Y Z
Published: December 2023

This paper introduces a theoretical description, force, and torque analysis of a Reaction Control Thruster (RCT) used as an actuator in Attitude Determination and Control Subsystem (ADCS). Mathematical formalization, realization, and implementation are offered to implement the RCT model using Matlab-Simulink. Furthermore, this paper proposes an accurate RCT Simulink model to control the orientation and stabilizes the Geostationary Earth Orbit (GEO) satellite within its orbit. Finally, a comparative analysis is carried out with an existing satellite platform (Eurostar-3000) based on the Root Mean Square Error (RMSE) for the delta velocity (delta-𝒱) parameter. The outcomes of the model simulation validated the effectiveness of the proposed approach.
Flexible harmonic domain model of solar PV supply system
Authors: Abdo M , Abdel-Rahman M A , Amer M , Helmy S
Published: December 2023

This paper presents a flexible harmonic domain (FHD) model of a grid-connected solar PV system amenable to harmonic analysis. The system consists of a 4.12 kW solar photovoltaic array that provides supply continuity and reliability for unmanned aerial vehicle (UAV) ground control station. The proposed system consists of a solar array, a boost converter, a three-phase inverter, and a three-phase filter. FHD technique is used to model the system, as it accounts only for dominant frequencies which enables obtaining of compact yet precise description of the system’s harmonic interactions. Compared to complexity, extra harmonic extraction routines, and large computational resources of the time domain technique (TD), FHD needs only one matrix inversion to obtain both the voltage/current waveforms and harmonic content of each part of the system. The obtained results prove the feasibility, accuracy, and simplicity of the proposed FHD technique for modeling switched devices while maintaining the computational resources. For each part/state of the proposed system, both the waveform and its harmonic content are visualized.
A new mathematical model to evaluate the effect of load inclination on aircraft shelter’s foundations
Authors: Elhanash M , Elsherif A K , Zaky H N , Nagy N M
Published: December 2023

Aircraft shelter is a structure or a reinforced hanger that has many uses in military aspects. It is used to protect military aircraft from different dangers such as enemy chemical attacks. Also, it provides housing, permitting aircraft maintenance and it can be storage for different weapons. therefore, optimum design of aircraft shelter is of a great importance. It may take several shapes to be suitable for its usage. It can be made from concrete, steel or composite materials. The foundations of an airplane shelter must be designed as best as possible. Design objectives are greatly impacted by the contact pressure between the earth and the foundation surface. Classical method in design assumes maximum uniform linear distribution of pressure under contact surface of footing. So, considering real contact pressure has a great interest for many authors. In this article, a new analytical method is proposed to study the effect of moments and load inclination on the design of rectangular isolated footing. The model proposed takes into consideration the real soil pressure. A parametric study was conducted and data obtained from classical model were larger than those from proposed model. Seven Rectangular isolated footings were designed using traditional method and proposed method. The proposed method is more economic since it provides less concrete dimensions. Results obtained from the new model were compared with FEM and achieved reasonable agreement.