Energy Performance Assessment Research Articles

Recent advances in data mining and machine learning for enhanced building energy management

Due to the recent advancements in the Internet of Things and data science techniques, a wide range of studies have investigated the use of data mining (DM) and machine learning (ML) algorithms to enhance building energy management (BEM). However, different classes of DM and ML algorithms feature different mechanisms and capabilities, resulting in their distinct roles and performance in BEM. Appropriate integration of different categories of DM and ML algorithms in BEM is essential to promote their wide application and provide guidance for new topic areas. This study presents a literature review of the use of DM and ML techniques in key areas of BEM, including building performance evaluation, energy usage prediction, and demand flexibility optimization. The review categorizes DM and ML techniques into three main categories, including supervised DM, unsupervised DM, and reinforcement learning (RL). Unsupervised techniques are primarily used for building energy performance assessment, while supervised techniques are mainly employed for building performance benchmarking and energy usage prediction. RL has been utilized for optimal building control to improve efficiency, demand flexibility, and indoor thermal comfort. The strengths, shortcomings, and integration of these methods in terms of their applications in BEM are discussed, along with some suggestions for future research in this field.

Thermal and energy performance assessment of naturally ventilated roofs with phase change material

The effect of incorporating phase change material (PCM) into roofing systems combined with natural ventilation is numerically and experimentally investigated. Four roof configurations, including ventilated and unventilated options with and without an air gap between the PCM and the insulation material, are subjected to experimental research during the winter season in a semi-arid climate using two fully instrumented modules. A sensitivity analysisis conductedthrough annual transient simulations fordifferentair gap dimensions and schedule openings. The experimental campaign demonstrates a decrease in the maximum peak indoor air temperature of between 1.9 and 4.4 %when the PCM is employed. Additionally, an increase in the minimum indoor air temperature between 4.4 and 10.4 % is achieved. Similarly, an improvement in the thermal performance of the PCMis observedwhen natural ventilation occurs, and it positively influences the interiorsurface temperature of the roof.Furthermore, the numerical results show almost zero annual thermal balance in the scenario where natural ventilation is allowed in the combination of 12 and 24 h per day through ducts with a diameter of 15 and 20 cm, respectively. Finally, this demonstrates that PCMroofs enhanced with natural ventilation could be an energy-efficientalternative for semi-arid climates under well-configured ventilation schedules and roof layers.

Thermal insulation and energy performance's assessment of a mycelium-based composite wall for sustainable buildings

Bio-composite insulation materials play a crucial role in reducing the environmental impact of buildings. This paper numerically investigates the eco-friendly application of mycelium in south-facing walls in Marrakech, Morocco, using 2D CFD simulations. In this context, the thermal efficiency of bio-sourced insulating materials was assessed and compared to that of conventional insulating materials. The study basically aims at the time lag and the decrement factor analysis to evaluate the dynamic thermal performance of a multilayer wall insulated with mycelium. A life cycle cost analysis (LCCA) is performed to establish the optimal thickness of the mycelium insulation, which was turned out to be 0.08m. This optimization leads to a substantial improvement in energy efficiency, resulting in energy savings increasing by 87.4% in winter and 55.9% in summer. Besides, during the last 72hours of the simulation, the indoor surface temperature drops by approximately 4 °C on summer days and raises by approximately 1 °C on winter days. The thickness of mycelium insulation was found to have a significant impact on energy savings, increasing them from 56% to 93%, and representing nearly a 1.7-fold improvement. The study has also targeted annual CO2 emissions to reveal a potential reduction of around 72% using optimal mycelium composite insulation. Finally, a comparative analysis with the guidelines of Moroccan thermal regulations was achieved. The obtained findings exhibit that the examined configuration excels in terms of thermal performance, economic feasibility, and environmental benefits.

Multi-Zone Energy Performance Assessment of Algerian Social Housing Using a Parametric Approach

Multi-Zone Energy Performance Assessment of Algerian Social Housing Using a Parametric Approach

Integrated design of multi-circuit thermal management system with battery waste heat utilization for new energy vehicle and performance assessment

A multi-circuit integrated thermal management system for new energy vehicle is proposed to realize the different coupling relationship between the heat exchanger for the cabin and the chiller for the battery through the four-way reversing valves and the solenoid valves. The effects of circuit selection, ambient temperature, driving test conditions and waste heat utilization on thermal management performance are discussed. The results indicate that thermal management can be carried out through three circuits in the system for heating conditions. The cabin is heated first in Circuit 1 and Circuit 3, while the battery has a higher priority in Circuit 2. The energy consumption in Circuit 1 is close to that in Circuit 2 at different ambient temperature. Compared with the other two circuits, Circuit 3 is more power-efficient, with energy consumption reduced by 14.81 %, and energy efficiency increased by 0.11 and 0.13 respectively at 10 °C of ambient temperature. The thermal management performance of Circuit 2 is least affected by the driving test conditions, and the maximum time difference of battery heating completion under different conditions is 284 s. High vehicle speed is beneficial to the waste heat utilization of the battery, for intense driving conditions, the energy consumption reduction ratio in Circuit 1 and Circuit 2 is more than 19.50 % and exergic efficiency is increased by more than 1.01 % in each circuit. Circuit 1 and Circuit 2 are better for intense driving conditions, and Circuit 3 is a good choice for urban driving conditions.

The energy performance assessment method to establish the best part build orientation in additive manufacturing

AbstractThe growing use of additive manufacturing (AM) processes pushes research towards studying methods to reduce their environmental impact. The part build orientation is a significant process variable, which can be chosen through the Energy Performance Assessment (EPA), a straightforward method. The paper presents a method for identifying the best part build orientation considering energy consumption. The EPA has been adapted for this purpose, resulting in an approach based on four steps. The method was employed to determine the best printing direction for three parts and two AM technologies.

Seasonal energy performance assessment of a hybrid HVAC system driven by solar and biomass energy for space heating and cooling in residential buildings

The H2020 project Hybrid-BioVGE aims to develop a sustainable HVAC system concept for buildings’ climatisation entirely based on renewable energy sources. The Hybrid-BioVGE system provides space heating/cooling and DHW production of small- and medium-scale buildings and deploys solar and biomass heat as energy inputs. During the heating period, thermal energy is provided directly by solar thermal collectors and a biomass boiler. The cooling energy demand is met by a thermally-driven ejector cycle based on a Variable Geometry Ejector (VGE), which adjusts its geometry according to two degrees of freedom. A demonstrator of the Hybrid-BioVGE system was designed and installed in a residential building in Porto (Portugal). The demonstrator’s seasonal energy performance was assessed numerically by a simulation model implemented in TRNSYS. Simulation results show that up to 98% of the system energy input is provided by renewables during the heating season, with a solar fraction higher than 60%. Conversely, the system energy performance is lower than expected during the cooling season due primarily to the limited performance of the heat rejection loop.

Energy Performance and Cost-Effectiveness Assessment towards the Nearly Zero-Energy School Buildings in Mild Climates

Energy Performance and Cost-Effectiveness Assessment towards the Nearly Zero-Energy School Buildings in Mild Climates

Labeling and assessment of energy and sustainability performances in the civil sector: The case study of ESA-ESRIN in Rome

The continuous improvement of the energy and sustainability performances of buildings is stimulated by mandatory rules, economic incentives and voluntary sustainability pathway of which energy efficiency is one of the most important components. The tools to evaluate the energy, sustainability, automation and energy metering performances of buildings, to check the status and lead the investments, are often complex, slow, expensive and related to the specific Countries, making difficult the job for the facility management departments of national or international organizations in EU.The present paper wants to give a contribute to existing literature by providing a new energy, sustainability, automation and energy metering label system to quickly, simply and economically evaluate the performances of office buildings in Europe. This tool has been tested on a case study, a research center of the European Space Agency (ESA-ESRIN) in Rome, Italy.The results of the test show that the tool has been successfully applied on the buildings of the research center using the data provided by the facility management department of ESA-ESRIN and the energy audit of the center. The labels can correctly represent the state of the buildings in a more cost-effective way if compared to the national energy certification and to international sustainability protocols.This study provides the facility management departments of public and private companies in EU - especially if they manage buildings in different EU nations - a reliable tool to quicky evaluate the energy, sustainability, automation and energy metering performances of their buildings.

Integrated Seismic and Energy Performance Assessment of Retrofitting Techniques: A Framework and Case Study for Indian Tropical Climatic Region

Integrated Seismic and Energy Performance Assessment of Retrofitting Techniques: A Framework and Case Study for Indian Tropical Climatic Region

Assessment of renewable power generation applied in homestay hotels: Energy and cost-benefit considering dynamic occupancy rates and reservation prices

Increasing the revenue from hotel operations and decreasing the stress on utility grids from hotel energy consumption are two priorities for the modern tourism industry. Dynamic occupancy rate and hotel reservation prices influence their operations revenue, while occupancy rate also impacts real hotel energy consumption. Renewable power generation as an effective measure can benefit hotels not only by decreasing electricity purchases but also increasing some extra income from selling electricity generated from renewable sources. This study investigated the effects of renewable power generation on energy and the cost-benefit performance of hotel operation prices under different occupancy rates and reservation prices. A two-stage energy and cost-benefit performance assessment and a novel comprehensive cost-benefit assessment model were developed to examine these research issues. The impact of the renewable power generation system (i.e., a photovoltaic-battery system installed on the building rooftop) was considered on the hotel energy and cost-benefit performance. It was found that the novel cost-benefit assessment model accurately quantified the overall hotel profit by calculating its energy consumption cost with the PV-battery system under different occupancy rates and reservation prices. Three typical homestay hotels located in Sanya were tested and assessed. The results showed that PV-battery systems effectively decreased the amount of electricity purchased by hotels. Besides, the renewable energy penetration was above 57.98% in various cases. The overall hotel profit increased by a maximum of 31.4% since renewable power generation was used under different occupancy rates and hotel reservation prices.

Assessment of energy and thermal resilience performance to inform climate mitigation of multifamily buildings in disadvantaged communities

The compound impacts of heatwaves and power outages pose a serious indoor heat-related health risk for residents living in disadvantaged communities (DACs) with limited or no air conditioning. In this study we selected 13 heat vulnerable multifamily buildings in El Monte, in Los Angeles County, and employed CityBES to evaluate their energy and thermal resilience performance. A retrofit package with seven passive and low-power active measures—cool roof, cool wall, window solar film, air sealing, internal blinds, natural ventilation, and ceiling fan—was evaluated under 2018 weather conditions and projected 2058 future weather conditions. Results show: (1) under the 2018 weather conditions, the retrofit package reduces the peak electricity load by 19 % and reduces the annual energy cost by $183 per housing unit; (2) the housing units without air conditioning would face heat danger conditions throughout the heatwave period. Although the retrofit package could reduce the heat danger hours by 50 % in 2018 and 34 % in 2058, air conditioning is a life-essential need for residents during heatwaves. These results indicate that, during the decision making of energy and climate retrofits for housing in DACs, policymakers and building owners should consider the co-benefits of reducing indoor heat-related mortality while reducing energy cost.

Improving the Energy Performance of Public Buildings in the Mediterranean Climate via a Decision Support Tool

Addressing Europe’s decarbonisation challenge involves widespread deployment of nearly zero-energy buildings, deep energy renovations and renewable energy integration in the building sector. Enhancing energy efficiency in public buildings necessitates tailored solutions and strategic planning involving Local Public Administration. This work focuses on advancing insights into the application of the PrioritEE Decision Support Tool in Portuguese public buildings, highlighting the energy and financial savings and carbon dioxide emission reduction potential. Using detailed building characterisation data from energy performance certificates, we applied the tool across 22 public buildings of diverse typologies in three distinct regions of Portugal, representing various public entities. Results demonstrate the tool’s adaptability, enabling a comprehensive assessment of energy performance and facilitating the exploration of customised energy efficiency and renewable energy solutions. The research emphasises the critical role of user-friendly tools in aiding policymakers and local administration technicians in meeting national renovation targets and contributing to the broader energy transition objectives.

Energy performance assessment of a novel enhanced solar thermal system with topology optimized latent heat thermal energy storage unit for domestic water heating

In this study, we introduce an innovative approach by incorporating a Topology-Optimized Latent Heat Thermal Energy Storage (TO-LHTES) unit with fins into a solar water heating system. Employing EnergyPlus software, we initially assess the energy and power requirements essential for meeting domestic hot water needs within the Moroccan context. Afterward, Computational Fluid Dynamics (CFD) analyses explore diverse Phase Change Materials (RT35, RT50, and RT60) under varying operational conditions, including injected temperature, velocity, and stored temperature. Our investigation extends to different climates, evaluating the energy savings potential. The study's outcomes reveal the remarkable efficacy of the enhanced solar system featuring the TO-LHTES unit, particularly with specific configurations—such as an injected temperature of 20 °C, injected velocity of 0.02 m/s, stored temperature of 80 °C, and RT50 as the chosen Phase change material. Given the poor thermal conductivity of many PCMs, effective heat distribution and storage necessitate innovative methods. While various finned heat exchanger structures have been explored in existing literature, a notable gap exists in non-intuitive heat exchanger concepts specifically tailored for LHTES units. This work contributes by presenting an innovative TO-LHTES unit design, advancing the understanding and applicability of latent heat storage in solar water heating systems. Importantly, a maximum energy savings of 63.2% was achieved.

Enhancing BIM-BEM integration: solutions for efficient data exchange and energy performance assessment

ABSTRACT This paper explores the efficiency of exporting data from Building Information Modeling (BIM) to Building Energy Modeling (BEM) and proposes solutions to encountered problems. The study considers both detached and attached buildings, analyzing the impacts of resolution parameters, and evaluating energy performance based on BIM model. A case-study approach is employed using a residential apartment building, with data exported from Autodesk Revit and imported into DesignBuilder. The results demonstrate the significance of adjusting resolution parameters (the primary parameters that influence the energy analytical model's accuracy and processing time) for efficient data export. Exploring different values leads to improvements in resolving unclosed spaces and enhancing the geometrical model of building elements. Challenges persist in allocating material finishes to walls. By improving and integrating energy performance evaluation through enhanced accuracy and efficiency of data exchange, the findings have significant impacts on stakeholders involved in building design, construction, and operation. Additionally, this process can optimize energy consumption in buildings. Further research is needed to address remaining challenges and improve BIM to BEM systems compatibility including the development of smart mechanisms for energy model creation and resolution parameters refinement. Case studies on different building types and long-term performance monitoring are recommended. This research contributes to the efficiency of exporting data from BIM to BEM interfaces, offering insights for practitioners and guiding future research in BIM-BEM tools integration.

Impact of future climate change on energy consumption in residential buildings: A case study for representative cities in Japan

This study examines the impact of future climate change on energy consumption in residential buildings in Japan, taking into account both the current and future typical meteorological year (TMY) database. TMY data is widely used in the building sector for energy performance assessments, system sizing, and optimization. To investigate the impact of current and future TMY databases on energy consumption of buildings, the study predicts the cooling and heating loads of residential buildings in four cities of Japan under the current (2020 ver.) and future (2086 ver.) TMY databases. Results show that the use of future TMY database leads to significant changes in air-conditioning heat loads of residential buildings in Japan. It finds that the annual cooling load in residential buildings of four cites of Japan increases by approximately 12% for Tokyo, approximately 9% for Toyohashi, approximately 8% for Osaka, and approximately 7% for Nagoya, respectively, however the annual heating load decreases by approximately 8% for Tokyo, approximately 9% for Toyohashi, approximately 6% for Osaka, and approximately 5% for Nagoya, respectively, compared to the current TMY database. This finding suggests that climate change will have a significant impact on future building energy consumption, and proposes energy-efficient building design as a solution to mitigate the impact of climate change on building energy consumption.

Energy Performance and Thermal Comfort Assessment of an Educational Building in Northern Italy: The Importance of Climatic Files in Energy Simulations

Energy efficiency and thermal and acoustic comfort play crucial roles in the design and management of educational buildings. The literature underscores their influence on students’ and teachers’ well-being and productivity. Additionally, numerous works emphasise the growing environmental awareness among children attending sustainably designed or adapted buildings. In light of these considerations, the present study aims to evaluate the dynamic energy performance of a school located in Northern Italy, conceived as a Nearly Zero Energy Building (NZEB). The school integrates various technologies, intelligent systems, and renewable sources to reduce energy requirements. A second aspect under evaluation involves using both real and virtual anemometers to generate crucial weather data for energy simulations. Dynamic analyses often rely on traditional meteorological year (Typical Meteorological Year) datasets derived from outdated sources, leading to inaccuracies in representing current climatic conditions, especially in the case of results related to a specific period.

Energy performance assessment of an auto-cascade cycle for ultra-low temperatures with the pair R1150 - R600a

Most of the research about auto-cascade refrigeration systems for ultra-low temperature applications is performed from a theoretical perspective due to the complexity of designing, testing, and measuring systems that work in two-phase conditions in most components of the cycle. A recent developed method has provided the opportunity to understand its thermodynamic peculiarities, which generally differ from the assumptions considered in simulation. This work presents for the first time, a consistent experimental evaluation of an auto-cascade refrigeration system for space temperatures between −80 to −60 °C. The work energetically optimizes a plant with the pair R1150/R600a using three different charging compositions (25/75 %, 30/70 % and 35/65 %) at a heat rejection temperature of 25 °C. Then, for the best option (340 g at 30/70 %), presents the thermodynamic evaluation at three heat rejection levels (25, 30, 35 °C) under steady-state conditions. Experimental measured COP ranged from 0.155 at a heat rejection temperature of 25 °C to 0.087 at 35 °C, with a rated cooling capacity decreasing from 139 W at 25 °C to 87 W at 35 °C.

Energy, economic, and environmental (3E) performance assessment, comparison, and analysis of airport cargo terminal microgrid system under the islanded and grid-connected modes

Microgrids, which can be grid-connected or isolated, may experience dependability issues as a result of intermittent renewable energy. The implementation of a hybrid renewable energy system (HRES) could alleviate this problem but is still a challenging task because of its interference, uncertain, and unpredictable nature. Currently, the absence of comprehensive assessment impedes large-scale applications. In this study, a novel 3E assessment method-based complete quantitative assessment is suggested and inventively integrated with a newly proposed triangle evaluation scheme. Loads of an airport cargo terminal, which are used to test the assessment approach, are classified into critical and non-critical categories according to their necessity. The microgrid system flexibility is considered by the trade-off of non-critical loads. Results show that the assessment method is more intuitive in quantifying the system's performance. The Levelized Cost of Energy (LCOE) in the islanded mode is lower than the current electricity price (from 0.5407 to 0.5439 CNY/kWh) and the annual carbon emission is reduced to one-third of that in the grid-connected mode. Its flexibility can effectively reduce dependence on backup power generation, where the daily peak shedding increases from 217.88 kW to 555.04 kW and daily hours without charging from 6.7 h to 8.9 h. The carbon emission decreases by 32 % considering the impacts of the system flexibility. Besides, the critical distance exists when the LCOE exceeds the current market electricity price.

Numerical sensitivity analysis of the energy performance of building envelope with dynamic conditions

The accurate energy performance assessment of building elements remains an active research topic. Studies have indicated that the thermal mass of building envelopes could influence heat losses in dynamic conditions and lead to significant difference in performance compared to steady-state conditions. This article aims to identify the relevance of using dynamic simulations instead of steady-state calculations for the energy performance assessment of building elements in Denmark. A numerical sensitivity analysis is performed on various parameters. The Monte-Carlo approach is used to perform numerous BSim simulations, which are then compared to standard steady-state calculations. The varied parameters include solar absorptance, ventilation in cavities, insulation material, insulation thickness, and orientation. Preliminary results indicate that dynamic conditions can significantly alter the wall heat losses, by up to 20% when compared to steady-state conditions. However, when aggregated, the differences average out to only 4% lower heat losses. When focusing on the thermal inertia of insulation materials, denser insulation materials only slightly delay the heat loss in the building element, but this effect is nullified over longer periods. The sensitivity analysis indicates that the most influential parameter is the solar absorptance, while the type of material is close in significance to the other parameters. The specific heat capacities and density of the insulation layer does not have a significant influence compared to its thermal conductivity. Thus, insulation materials with higher thermal mass do not seem to significantly improve the thermal performance of a building envelope.