Conference Agenda

This paper presents a methodology for integrating terrain shadows of micro-locations into building energy modeling (BEM) for topographically diverse regions. Dynamic energy simulations rely on high-resolution weather data sourced from reference locations that cover a climate zone. As soon as the micro-location of the simulated building is away from the weather reference site, topographic shading can trigger deviations. This study developed a three-dimensional reproduction of the micro-location’s surrounding terrain as a simplified ring model based on available horizon height captured from PVGIS. In a radius of 20 km, 4 Slovenian cities from the same climatic zone have been analyzed and compared with a baseline calculation. When comparing solar gains (SG) of chosen micro-locations, a tendency is noticeable - the lower the Sky-view Factor (SVF), the higher the SG deficit. Additional calculations have been conducted for different SVF / aspect ratios and used in a geographical survey. Results show that at least half of the Slovenian land surface, which is inhabited by 21% of the population, has characteristics where topography influences calculated Solar Gains (SG). In those areas, the potential SG deficit is distributed from barely perceptible to more than 25% in certain areas. This approach enhances the precision of BEM in topographically varied landscapes and can inform better design and planning decisions.

This work aims to present and evaluate different techniques to reduce energy consumption in residential buildings under the climatic conditions of Jeddah city, Saudi Arabia. The study was taken on a residential building with an area of 250 m2 with an energy demand of 370 kWhm-2 for cooling. The proposed techniques include several techniques including the use of four different types of thermal insulation and different thicknesses from 50 mm to 300 mm. It also includes the effect of using thermal insulation on the wall or in the ceilings. It also includes studying the effect of the type of windows used and window areas compared to wall areas. The energy demand of buildings using the proposed techniques is evaluated and compared under different conditions throughout the year. The building and the proposed techniques will be simulated using TRNSYS software throughout the year. The results showed that using double-glazed windows reduces energy requirements by 8.34% compared to single-glazed windows and reducing the window-to-wall ratio from 75% to 25% reduces energy demand by 1.43% to 3.08% respectively. Using thermal insulation on the exterior walls and roof reduces energy demand by 13.42% com-pared to insulation on the roof only. The maximum energy reduction was achieved with wall insulation with roof with 21.41 %.

Currently, we are facing the impact of the ongoing global warming. To reduce the inevitable consequences of climate change we should aim to promote environmental- and energy-efficient solutions to be applied in the building sector. Considering the increasing improvements in the energy performance of the building envelopes, we should aim for operational solutions to decrease the operational emissions. With the growing share of Renewable Energy Sources (RES) usage, energy flexibility is of rising importance. Building Energy Flexibility (BEF) can be utilized with the utmost potential if measured for a group of buildings, considered as an Energy Cluster (EC). Various short- and long-term techniques can be included in the successfully operated EC to encourage its flexibility. The overall efficiency of the Energy Flexible Building Cluster (EFBC) can be evaluated considering energy-, economic-, or environmental-related criteria.

In this article, the energy flexibility of the examined case study neighborhood consisting of representative single-family houses is optimized. The examined cluster, defined using the satellite map, consists of 202 single-family houses, located in Lodz (central Poland). The examined EFBC is evaluated with a function of energy, economic, and environmental profitability. The examination is performed assuming each building of the cluster as an active participant in the local energy infrastructure, being a prosumer i.e. both, energy consumer and producer. The provided flexibility is quantified by the reduction in conventional energy consumption, as well as a decrease in carbon emissions. The assessment aims to optimize the energy demands in response to external forcing factors, in particular short-term (a day ahead) weather and energy price forecasts. The presented outputs allow to assess the profitability of some flexible energy management strategies at the cluster level. The discussed optimization on the cluster scale allows the exploitation of more efficient RES usage, emissions reductions, and improvement of grid safety (on various levels of application).

Abstract. This study investigates the impact of window type, window-to-wall ratio (WWR), and shading on energy efficiency and lighting per-formance in a case study located in Budapest, Hungary. By utilizing DesignBuilder software for building performance simulation, the re-search explores various configurations involving triple and double glaz-ing, with and without shading, across WWRs of 10% and 50%. The study evaluates heating, cooling, and lighting energy consumption, comparing the performance of each scenario to identify strategies that optimize both energy efficiency and occupant visual comfort. The find-ings reveal that triple glazing with shading and a 50% WWR achieves the efficient performance, minimizing electricity consumption through effective solar heat gain control and optimized daylighting. In contrast, higher WWRs without shading result in increased cooling demands, lowering overall energy efficiency despite enhanced daylight penetration. The results underscore the critical importance of integrating shading de-vices with appropriate window designs to mitigate solar heat gain and balancing thermal comfort with lighting needs.

A concise and simple rule that accompanies designers of low-energy buildings is to minimize heat losses and maximize energy gains. Most often, however, both parts of the energy balance of buildings are artificially separated what may result in poor efficiency of the final product. In the article, the authors present the basic aspects connected with application of the Active Thermal Insulation (ATI) that combines in one system reduction of heat losses and efficient use of free renewable energy. The principle of its operation consists in creating a surface (in reality a layer) in the external building shell with a temperature significantly higher than the temperature of the external environment and at the same time lower than the temperature in the room. In such conditions, the temperature gradient causing heat flow from the interior of the building is reduced and, as a result, heat losses through the external partition are significantly reduced. In practice, active insulation takes the form of a plastic coil embedded, for example, in a several-centimeter layer of well conducting concrete layer. A medium circulates in the coil in a forced manner, transferring energy from ground exchanger, low-parameter return water discharged into the ground in a geothermal installation or finally warm mine water discharged into the river.

The key energy and economic effect of ATI is that this system directly uses free renewable heat sources with low exergy, which are practically useless without any additional conversion (e.g. using a heat pump and the associated additional energy and cost inputs). A little amount of non-renewable energy in the active insulation system is only needed to run the circulation pump in the coils.

Very extensive field measurements results held by the authors, collected in the building located in Central Europe that was built by Tamas Barkanyi, have shown that the use of the ATI system can reduce heat losses through the opaque building envelope by up to 60% during the heating season. Now the authors try to answer the question how to further refine the system and adjust it to the local climate conditions. For this purpose, the simulations are being carried out regarding the required position of the ATI in the wall in local climate, proper selection of the type and thickness of the material layers, pipe spacing etc. The conducted research works aim to prepare procedures and solutions that can be used in common design practice.

Improving the energy efficiency of existing institutional buildings is vital for reducing energy consumption and enhancing sustainability. This study investigates retrofitting strategies for the Solar Energy Institute building at Ege University, integrating passive and active measures tailored to local climatic conditions to achieve nearly zero-energy standards while considering occupant comfort and future climate scenarios.

In this paper, we demonstrate that combining building physical calculations of the thermal envelope, Building Energy Modeling (BEM) using DesignBuilder, and Building Information Modeling (BIM) enabled precise visualisation and analysis of interventions. Passive measures included thermal insulation, window replacement, daylighting optimisation and lighting upgrades, while active solutions involved improving the HVAC system and integrating a rooftop solar energy system. User behaviour calibration, informed by measured energy consumption and temperature data, bridged the performance gap between simulated and real-world conditions. Simulations under future climate scenarios further revealed potential resilience and comfort challenges, with overheating risks mitigated through adaptive solutions.

This approach underscores the importance of incorporating user behaviour, dynamic climate models, and comparative simulation techniques in energy-efficiency-increasing complex and deep renovation projects. Comparing DesignBuilder outputs with advanced numerical methods validated the reliability of modelled building performance, particularly in areas such as ground contact slabs and other building envelope components. These findings contribute to a deeper understanding of sustainable retrofitting strategies, emphasising the synergy between advanced modelling tools and measured data to optimise energy performance and indoor environmental quality.

By addressing the complexities of retrofitting through comprehensive analysis and future-proofing measures, this study provides actionable insights for transitioning institutional buildings toward sustainability in the face of evolving climatic and operational demands.​