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Mixed-mode ventilation system (MMVS) can significantly decrease the energy consumption of Egyptian office buildings while meeting indoor air quality requirements and thermal comfort of occupancy. This paper studies the effect of using mixed-mode ventilation system (MMVS) in achieving both energy efficiency and thermal comfort in office buildings. The research specifically focuses on investigating the energy-saving potential and thermal performance of existing office buildings in Egypt by merging natural ventilation (NV) with mechanical ventilation (MV) to reach an effective mixed-mode ventilation system (MMVS). Additionally, an energy performance simulation was used to study how to achieve thermal comfort and the building's indoor temperature. Firstly, a selected office building in Cairo was used as a case study, and its thermal performance was studied by simulation. Secondly, site measurements were conducted to record the real thermal performance of the tested office building. These measurements were used for the validation phase. The validation demonstrated a satisfactory agreement between the building simulation and measurement data for air temperature (T) and relative humidity (RH). Thirdly, building energy simulations and analysis were used for testing the energy performance and thermal comfort of the tested scenarios that have different alternatives in the operation settings. The results revealed that it is possible to increase the thermal comfort hours by merging natural ventilation and applying the mixed-mode ventilation system only by changing the operation settings on the MMVS performance. The building's annual energy consumption was reduced by approximately 27 % compared with the use of HVAC in the building. Natural Ventilation hours increased by approximately 27 % to reach 427 hours (h) and the HVAC hours decreased by 17 % to reach 898 hours (h). [ABSTRACT FROM AUTHOR]

The demand for low-carbon and energy-efficient building designs is urgent, especially considering that building energy consumption constitutes a significant part of global energy usage. Unlike small to medium-sized buildings such as residential and office spaces, large public buildings, like sports facilities, have unique usage patterns and architectural forms, offering more significant potential for energy-saving strategies. This review focuses on sports buildings, selecting 62 high-quality papers published in building science over the past 30 years that investigate low-carbon and energy-efficient research. Summarizing and synthesizing these papers reveals that current studies predominantly concentrate on four main areas: indoor air quality, ventilation, thermal environment, and energy consumption. Notably, many studies emphasize improving indoor thermal comfort and reducing energy consumption in sports buildings through measurements and evaluations of indoor thermal environments, temperature distributions, heat transfer phenomena, and energy consumption analyses. Key outcomes indicate that green technology innovations, such as energy substitution technologies, significantly enhance energy efficiency and reduce CO2 emissions. However, present research emphasizes singular energy-saving approaches, suggesting future directions could integrate comprehensive green technologies, life-cycle assessments, and applications of intelligent technologies and the Internet of Things (IoT). These enhancements aim to provide more effective and sustainable solutions for implementing green, low-carbon energy practices in sports buildings. The review emphasizes that in order to accomplish sustainable urban growth and achieve global carbon neutrality targets, a comprehensive approach involving technical innovation, legislative assistance, and extensive preparation is crucial. [ABSTRACT FROM AUTHOR]

One of the technical solutions to improve indoor thermal comfort and reduce energy consumption in buildings is the use of demand-controlled ventilation (DCV) systems. The choice of the control method becomes more important when the walls in the room are finished with moisture-buffering materials. This study explores the impact of four DCV system control scenarios (control of temperature, relative humidity, and carbon dioxide concentration for two different supply airflows to the room) combined with various indoor moisture-buffering materials (gypsum board and cement–lime plaster) on the variability of indoor air quality parameters, thermal comfort, and energy. The analysis was performed by computer simulation using WUFI Plus v.3.1.0.3 software for whole-building hydrothermal analysis. Control-based systems that maintain appropriate relative humidity levels were found to be the most favourable for localised comfort and were more effective in terms of energy consumption for heating and cooling without humidification and dehumidification. This research also revealed that the moisture-buffering effect of finishing materials can passively contribute to enhancing indoor air quality, regardless of the room's purpose. However, higher energy consumption for heating was observed for better moisture-buffering materials. [ABSTRACT FROM AUTHOR]

The article presents a special stand featuring ion generators designed and manufactured for experimental research. This study investigates the use of ion energy for air purification, specifically focusing on its effect on PM (0.3–10 μm) agglomeration. By introducing charged ions into the air, particulate matter can be charged, resulting in increased particle sizes through agglomeration, and subsequently improving the filtration efficiency. Experiments were conducted in a controlled chamber to evaluate the performance of an ion-based air purification system. The effects of various parameters, such as ion concentration, airflow rate, and particle size distribution, on PM agglomeration were studied. The results demonstrated that the ion-based air purification system could effectively enhance PM agglomeration, particularly for ultrafine particles. The study also revealed that the efficiency of PM agglomeration was influenced by the ion concentration and airflow rate, with an optimal range identified to maximize the system's performance. Furthermore, the potential real-world application of this technology was discussed, considering factors such as energy consumption, maintenance requirements, and compatibility with existing air purification systems. This study contributes to the development of innovative air purification solutions and offers valuable insights into the potential of ion energy for improving indoor air quality and safeguarding human health. [ABSTRACT FROM AUTHOR]

Among the existing techniques to mitigate the problem of contamination in the indoor environment, photocatalytic technology is considered to be the most promising solution in terms of effectiveness and cost. To that end, in the frame of the LIFEVISIONS project, a novel photocatalytic powder (photo-powder) was mixed in paints' matrix, producing a photocatalytic building material (photo-paint) able to improve indoor air quality (IAQ), upon its application, without downgrading paint physical properties. As a result, of IAQ improvement, less energy will be needed from ventilation systems, addressing not only health issues related to air quality but also energy reduction targets. Many powder formulae were synthesized using different synthetic pathways, concentration of dopants, and TiO2 particles' size. They were tested in a photocatalytic reactor (lab-scale tests), according to EN 16980-1:2021, under visible light and the results showed that the most promising photocatalytic performance degrades 85.4% and 32.4% of nitrogen oxide (NO) and toluene, respectively. This one was used for the production of two different kinds of paints, organic (with organic binder) and inorganic (with potassium silicate binder), in an industrial scale. Both were tested in the Demo Houses' prototype demonstrator (real-scale tests) with an ultimate scope to estimate their effectiveness to degrade air pollutants under real-world conditions. In addition, the reduced energy consumption as a result of less ventilation needs was calculated in Demo Houses. More specifically, the energy reduction based on simulation results on Demo Houses was more than 7%. Although lab-scale tests showed better photocatalytic performance than the real scale, the efficiency of the paints under a more complicated environment was very promising. [ABSTRACT FROM AUTHOR]

Facing the current sustainability challenges requires reduction in building stock energy usage towards achieving the European Green Deal targets. This can be accomplished by adopting techniques such as fault detection and diagnosis and efficiency optimization. Taking an Estonian school as a case study, an occupancy-based algorithm for scheduling ventilation operations in buildings is here developed starting only from energy use data. The aim is optimizing the system's operation according to occupancy profiles while maintaining a comfortable indoor climate. By relying only on electricity meters without using carbon dioxide or occupancy sensors, we use the historical data of a school to develop a DBSCAN-based clustering algorithm that generates consumption profiles. A novel occupancy estimation algorithm, based on threshold and time-series methods, then creates 12 occupancy schedules that are either based on classical detection with an on-off method or on occupancy estimation for demand-controlled ventilation. We find that the latter replaces the 60% capacity of current on-off schedules by 30% or even 0%, with energy savings ranging from 3.5% to 66.4%. The corresponding costs are reduced from 18.1% up to 62.6%, while still complying with current national regulations for indoor air quality. Remarkably, our method can immediately be extended to other countries, as it relies only on occupancy schedules that ignore weather and other location-specific factors. [ABSTRACT FROM AUTHOR]

This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact. This study focused on the implementation and development of dynamic insulation technology for a sustainable and energy-efficient future in the region, especially in Iraq. The study assessed the energy efficiency of dynamic insulation technology by analyzing three wall models (static, dynamic, and modified) during the winter season. This paper expands the analysis to include a hot, dry summer scenario, providing valuable insights into the year-round performance of dynamic walls and enabling sustainable and energy-efficient solutions for Iraq's climate. The study evaluates the thermal efficiency of the dynamic intake and exhaust facades during the cooling season for the city of Baghdad. The finding indicated that the dynamic intake facade reduces energy consumption by 16.3% for the dynamic wall and 17.2% for the modified dynamic wall. In addition, the dynamic exhaust front reduces energy consumption by 46% during the cooling season, with the maximum permissible exhaust air level. Dynamic insulation is suitable for hot and dry climates, improving energy consumption. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to formulate a user-friendly pre-design model that could be a decision support tool for green wall systems to assist designers in selecting an optimal green wall system aligned with specified performance criteria while concurrently addressing project requirements linked to social and economic parameters. This approach seeks to enhance overall project satisfaction for the designer and the owner. Design/methodology/approach: A correlation between the green wall context and design requirements and its performance on the buildings have been defined by considering its social and economic parameters, which represented the owner preferences to ensure the most satisfaction from installation as it achieves the required performance that is defined by the designer such as maximizing thermal insulation, improving indoor air quality, reducing the needed heating and cooling loads, etc. and also to achieve the satisfaction in social and economic requirements defined by the owner such as system installation cost, system maintenance cost, adding beauty value, etc. Findings: The research developed an easy pre-design model to be a tool for green wall system decision-making for the most suitable system, which contains three main steps: the first one is defining the required performance of the green wall (designer requirements), the second step is limiting the context of the project which is made by designer and the owner requirements and finally the third step is choosing the system components that ensures achieving the requirements of both owners and designer, related to the building and climate context. Originality/value: The added value lies in developing a green wall decision-making tool, essentially a pre-design model. This model considers the correlation between the project's context, encompassing climate and building conditions. It provides a structured approach for decision-making in the early stages of green wall design. It offers valuable insights into the optimal choices related to system type, installation methods and plant characteristics. This enhanced decision-making tool contributes to more informed and efficient design processes, considering each project's specific needs and conditions. [ABSTRACT FROM AUTHOR]

Lecture rooms in the Philippines often experience unfavourable temperatures and elevated carbon dioxide (CO2) concentrations, impacting the well-being, health, and learning efficiency of both students and educators. This research seeks to evaluate the thermal comfort, indoor air quality, and energy usage in a standard Philippine lecture room by implementing a membrane-type total heat exchanger (MemHEX). The research used computational fluid dynamics (CFD) simulations, which were validated by field measurements and showed the effectiveness of the MemHEX. Energy consumption was modelled using EnergyPlus to compare potential impacts of various ventilation approaches. Room temperature and humidity fall short of thermal comfort standards, suggesting the need for a higher-capacity air conditioning unit (ACU). Average CO2 concentration exceeds 1000 ppm, signalling a demand for ventilation. Post-MemHEX installation, temperature and humidity slightly rise with increased air changes per hour (ACH), introducing warm outdoor air. Indoor air quality improves with rising ACH, reducing CO2 levels by exchanging fresh outdoor air. Comparing mechanical ventilation and MemHEX reveals MemHEX as more energy-efficient, maintaining better indoor conditions. These findings provide valuable insights for the field of research by demonstrating the feasibility and benefits of using MemHEX to improve the indoor environment and energy efficiency of a typical Philippine classroom. [ABSTRACT FROM AUTHOR]

In modern life, strategies developed in line with the increasing energy demand cause many environmental problems on a global scale. One of the most important of these problems is inadequate indoor air quality. The most critical parameters affecting indoor air quality during the design phase are selecting wrong and unhealthy building products, insufficient window sizes, and unplanned natural ventilation. This study investigates whether indoor air quality can be improved only by effective natural ventilation methods, without compromising thermal comfort, through small changes that can be applied to buildings. For this purpose, simulation studies were carried out to reveal whether indoor air quality could be improved without compromising thermal comfort in a library building. As a result, when evaluating the improvement recommendations, the thermal comfort range for the cross-ventilation and chimney effect ventilation recommendations is 'comfortable' in winter and 'comfortable-partially comfortable' in summer. For the ventilation recommendations with roof wings, skylights and wind towers, the thermal comfort range for summer and winter remained in the "comfortable" range due to the high natural ventilation performance. [ABSTRACT FROM AUTHOR]

Energy efficiency norms require effective insulation techniques for buildings in order to minimize energy consumption. The paper presents simulations, carried out throughout the year, regarding the efficiency of energy recovery units (ER) to ensure the quality of fresh indoor air. Indoor air energy recovery calculations were performed using plate and rotary heat exchangers in different operating scenarios. The evaluated parameters led to the stability of the optimization solutions in order to obtain a higher energy efficiency on the equipment. By comparing the obtained results, optimal measures and solutions were identified for energy efficiency in the operation of ER. [ABSTRACT FROM AUTHOR]

In Poland and other countries in Central Europe, residential buildings from the second half of the 20th century dominate, which have recently undergone deep thermomodernisation. Research on the retrofitting of residential buildings has focused mainly on energy efficiency, with only a few studies on indoor air quality. The aim of this study was to present a comparative analysis of the impact of five ventilation scenarios (three natural and two mechanical) on CO2 concentration and energy demand for heating and ventilation in residential spaces of a multi-family building located in Poland. The analyses were based on the results of building performance co-simulation using the EnergyPlus and CONTAM programs carried out under dynamic conditions with a 5 min time step for the entire heating season. The calculations took into account the instantaneous occupancy variability of twenty apartments. In the buildings equipped with new tight windows, the natural ventilation system provided extremely low air exchange (on average 0.1 h−1) and poor indoor air quality (average CO2 concentration at the level of 2500 ppm). Opening windows to ventilate the rooms generated a multiple increase (up to 8 times) in heating demand during these periods, but average CO2 concentration was on the level of 930 ppm. The use of mechanical ventilation was profitable both in terms of energy savings (at the level of 50%) and improvement in the indoor air. [ABSTRACT FROM AUTHOR]

Purpose: To significantly adopt and improve indoor energy efficiency in building infrastructure in developing countries can be a challenging venture. Thus, this study aimed to assess the satisfaction of indoor environmental quality and its effect on energy use intensity and efficient among student housing. Design/methodology/approach: The study is quantitative and hinged on the contrast theory. A survey of 1,078 student residents living in purpose-built student housing was contacted. Using Post-Occupancy Evaluation and Multiple Linear Regression, critical variables such as thermal comfort, visual comfort and indoor air quality and 21 indicators were assessed. Data on annual energy consumption and total square metre of the indoor area were utilised to assess energy use intensity. Findings: The study found a direct relationship between satisfaction with indoor environmental quality and energy use intensity. The study showed that students were more satisfied with thermal comfort conditions than visual and indoor air quality. Overall, these indicators contributed to 75.9% kWh/m2 minimum and 43.2% kWh/m2 maximum energy use intensity in student housing in Ghana. High occupancy and small useable space in student housing resulted in high energy use intensity. Practical implications: Inclusions of sustainable designs and installation of smart mechanical systems are feedback to student housing designers. Again, adaptation to retrofitting ideas can facilitate energy efficiency in the current state of student housing in Ghana. Originality/value: Earlier studies have argued for and against the satisfaction of indoor environmental quality in student housing. However, these studies have neglected to examine the impact on energy use intensity. This is novel because the assessment of energy use intensity in this study has a positive influence on active design incorporation among student housing. [ABSTRACT FROM AUTHOR]

Accelerated concrete carbonation is an expanding option for decarbonizing construction. Factors such as concrete mixture design and carbonation environment can influence the maximum CO2 utilization that can be achieved during such a process. A carbonation process designed to utilize a water‐saturated dilute CO2 source wherein 2 < CO2 concentration (v/v%) < 16, was modeled in AspenPlus©. A regression model was developed to correlate CO2 uptake, relative humidity (11%–100%), CO2 concentration ([CO2] = 2—16 v/v%), and temperature (T = 11–74°C) conditions within a carbonation reactor. It was determined that [CO2] was the most significant variable as higher concentrations enhanced CO2 transport through the concrete. The energy use intensity per mass of CO2 utilized (kWh/kgCO2) was determined across a range of processing conditions. As a function of the operational conditions, accelerated carbonation provides a net CO2 reduction of up to 28 kgCO2/tonne of concrete; a reduction of up to ~45% compared to typical formulations. [ABSTRACT FROM AUTHOR]

The growing emphasis on indoor air quality and public health is fuelling the need for efficient yet affordable air purification techniques. In this study, the influence of biochar particle size on its adsorption efficiency toward airborne pollutants was examined. Bark-derived biochar particles were treated by grinding or ball milling, and then, seven samples with different particle size groups were separated. Biochar particles were characterized by particle size, proximate, SEM, XRD, and physisorption analyses. For adsorption efficiency, two different pollutants were tested at variable initial concentrations. The physical composition and XRD patterns of the biochar with different particle sizes were comparable. The ball-milled sample was an exception in that it had higher ash content and additional XRD peaks signifying contamination of the sample. The porosity of biochar was greater in smaller particles. Ball milling increased the specific surface area and total pore volume by 102% and 48%, respectively. Biochar with finer particle size exhibited the highest adsorption potential towards formaldehyde and methanol among other samples. It should be emphasized that simple mechanical grinding is preferred for reducing biochar size to avoid the risk of eventual contamination, greater energy consumption, and slower processing related to ball milling. When a low concentration of pollutant was tested (1 ppm formaldehyde), the effect of particle size on the adsorption efficiency was more noticeable. However, the effect of particle size was less dominant when higher concentrations of pollutants were tested. Smaller biochar particles (<100 μm) are more favourable for indoor air remediation given their superior adsorption efficiency of volatile organic compounds occurring at low concentrations in the buildings. [ABSTRACT FROM AUTHOR]

The aim of the study is to analyse energy consumption for heating in set of the school buildings. Data analysis includes three data sets – predictions from energy performance certificates (EPC), measured data from heat meters and measured climate corrected data. Data sets were statistically checked and processed and represented graphically. The actual energy consumption differs from the one stated in the EPCs in all cases, which means that schools consume on average 15 % more energy than it is stated in the EPC. Overall, the data reveal that the actual energy consumption differs from the theoretical consumption, with all schools having higher actual consumption than the theoretical values. The differences in the data sets are discussed, and possible improvements are suggested taking into account strong relation between energy consumption and indoor air quality. [ABSTRACT FROM AUTHOR]

Nowadays, indoor air quality (IAQ) and the energy performance of buildings are two main scientific and technical challenges because they are in direct connection with human health and the depletion of energy resources. In this study, we analyzed the influence of an outdoor air flow introduced through a mechanical ventilation system, focusing on the two aforementioned topics. A standardized ventilation rate (25 m3/h/person) led to an increase in the indoor O3 concentration (from 5 μg/m3 to 50 μg/m3) and, simultaneously, to a decrease in the indoor CO2 concentration (from 2000 mg/m3 to 800 mg/m3), a decrease in the PM2.5 concentration (from 300 μg/m3 to 150 μg/m3), and the maintenance of a constant indoor HCHO concentration. In our study, a new, single indoor air quality index, IIAQ, is proposed. This new index presents different implications: on the one hand, it has the ability to simultaneously take into account several pollutant species, and on the other hand, it can prioritize the ventilation strategy that responds to the extreme values of a certain pollutant. Moreover, indoor air quality classes were elaborated, similar to energy classes. The possibility of using this new index simultaneously with energy consumption may lead to ventilation strategies that are adaptative to dynamic outdoor pollutant concentrations. [ABSTRACT FROM AUTHOR]

Shared public buildings have become centers of innovation, integrating advanced technologies to meet evolving societal needs. With a heightened emphasis on occupants' health and well-being, these buildings serve as hubs for technological convergence, facilitating seamless connectivity and intelligent data analysis and management. Within this context, environmental monitoring emerges as a foundational element, pivotal to all aspects of building management. This article provides findings from the nationally funded RE-START project, which focuses on shared public buildings, with special regard to educational and medical facilities. The project explores enhanced indoor air quality monitoring, focusing on CO2 concentration that is directly correlated with occupancy, as a fundamental element for developing health and safety protocols, energy efficiency strategies, the integration of smart building technologies, and data-driven energy management. The intersection of environmental monitoring, energy efficiency, security, and IoT technologies in in indoor spaces is relevant. The outcomes of the study reveal the delicate nature of all the involved components, which need to be carefully developed in an integrated manner. [ABSTRACT FROM AUTHOR]

Building fresh air supply needs to meet certain regulations and fit people's ever-growing indoor air quality demand. However, fresh air handling requires huge energy consumption that goes against the goal of net-zero energy buildings. Thus, in this work, an adaptive fresh air pre-handling system is designed to reduce the cooling and heating loads of HVAC system. The sky-facing surface of the system uses electrochromic mechanism to manipulate the optical properties and thus make full use of solar energy (solar heating) and deep space cold source (radiative cooling) by switching between heating and cooling modes. In the cooling mode, the sky-facing surface shows a transmittance of down to zero, while the reflectance is high at 0.89 on average. In the heating mode, the electrochromic glass is highly transparent, allowing the sunlight to reach the solar heat absorber. To obtain the energy-saving potential under different climates, six cities were selected from various climate regions in China. Results show that the adaptive fresh air pre-handling system can be effective in up to 55.4% time of a year. The maximum energy-saving ratios for medium office, warehouse, and single-family house can reach up to 11.52%, 26.62%, and 18.29%, respectively. In addition, the system shows multi-climate adaptability and broad application scenarios, making it a potential solution to building energy saving. [ABSTRACT FROM AUTHOR]

In buildings, air conditioning and mechanical ventilation (ACMV) systems are the major shareholders of overall energy consumption. Energy-efficient designs for ACMV systems in building applications are therefore needed. While designing an efficient ACMV system, consideration must be given to the growing concerns of enhanced thermal comfort and improved indoor air quality. The variable refrigerant flow (VRF) air-conditioning system is a widely adopted alternative to the existing building cooling systems due to the higher energy efficiency and individualized temperature control feature. However, it still suffers from shortcomings such as no outdoor air induction for ventilation and higher initial cost. Therefore, this paper reviewed the variable refrigerant flow and mechanical ventilation/air distribution systems, their integrated designs for non-residential buildings, performance evaluation and control optimization of the integrated systems, VRF systems' faults detection and diagnosis, current application of the VRF systems, and associated challenges. Together with these all, some advanced buildings' cooling techniques and improvements toward nearly/net-zero energy buildings are briefly discussed. Indoor thermal comfort models and criteria for different climates are also presented for an in-depth understanding of the VRF integrated mechanical ventilation designs. The literature survey shows that the supply air temperature and airflow rate are foremost in parameters that can be optimized in VRF integrated ventilation design as they greatly reduce the energy consumption. Further, policies on elevated indoor temperatures in air-conditioned buildings to mitigate their carbon footprint are strictly being implemented. Therefore, this review provides an insight to the researchers for further improvement in the integrated design and control optimization of the parameters involved. A paradigm shifts from the conventional compression-based electric-powered air conditioning systems to the renewable energy driven advanced air conditioning technologies which is also an emerging research area to be focused on achieving the target of nearly/net-zero energy buildings. [ABSTRACT FROM AUTHOR]

Traditional buildings have a central role to play in Europe's plans to be the first climate-neutral continent by 2050, with the building sector being the single largest energy consumer in the EU with 40 per cent of total energy use. Seventy-five per cent of the existing housing stock is energy inefficient with minute numbers renovated each year. Existing buildings offer huge potential for energy use reduction. Research has shown that a historic retrofit can emit less carbon compared to demolishment and rebuilding. Reductions in carbon emissions of up to 62 per cent were observed across a body of case studies by Historic England, including a 95 per cent reduction in the mews case study described in this paper. Moreover, carefully managed thermal retrofits, taking a 'whole house approach', have many benefits, including improved indoor comfort and air quality as well as reduced operational costs. These are factors which are fundamental in ensuring the continued use of historic constructions while improving their standards of preservation and durability. Thermally upgrading traditional building is still a much-debated topic. Inappropriate thermal interventions with unsuitable materials and finishes can have unforeseen consequences, resulting in building damage and a reduction in internal comfort, health and well-being. This paper aims to contribute to this discussion by providing an overview of key considerations when thermally upgrading the walls of traditional buildings while preserving unique characteristics and functionality. Advantages of adopting thermal mortars such as cork lime are put forward, and their potential efficacy is discussed, concluding with a case study focusing on the deep retrofit of a London mews within a conservation area. [ABSTRACT FROM AUTHOR]

This document is an editorial from the journal "Applied Sciences" discussing the importance of renewable energy systems in reducing greenhouse gas emissions. It highlights the challenges associated with increasing energy demand and the need for a sustainable energy paradigm. The editorial summarizes the research topics covered in a special issue of the journal, including power plants based on solar, wind, and biomass systems. It also discusses other innovative solutions for energy inefficiency in various sectors. The document aims to provide library patrons with up-to-date advancements and studies related to renewable energy integration. [Extracted from the article]

With recent and unprecedented attention toward the implementation of Energy efficient building which aids in advocating sustainable construction, numerous attempts have made in establishing flexible approaches to which these practices will assist in savings cost of construction, improve the quality of indoor air as well as lowering the GHG emissions. However, the system is lacking proper and standardized methodology of implementations. Therefore, this, study dwelt in examining several factors capable of influencing the application of energy conservation practices in buildings, along with the advantages and barriers for implementation based on existing literatures, which focuses on raising awareness, providing information, implementing proper policies, and creating incentives to provide alternative solutions for building owners. As presented, study's outcomes offer a blueprint for comprehending the nuanced dynamics of building energy efficiency and lay out a clear course for further investigation. The study also, identifies significant factors which majorly influences building energy efficiency which include government supervision, design standards, construction quality, and energy-efficient materials. The study recommends utilizing cutting-edge innovations, building automation systems, and IoT devices to improve energy monitoring and conservation. [ABSTRACT FROM AUTHOR]

Before the COVID-19 pandemic, ventilation in buildings was not always given its due importance. The World Health Organization has highlighted the important role of air exchange with the outdoors in improving the air quality in buildings; buildings should, therefore, be equipped with mechanical ventilation or adequate air conditioning systems. This paper aims to investigate different retrofit solutions for air conditioning, evaluating them in terms of energy consumption and cost and the impact of increased outdoor air exchange rates on countering the propagation of COVID-19; the latter is the main novelty of the paper. As a case study, we take an existing office building located in Central Italy that was previously not equipped with a mechanical ventilation system (a system with primary air was introduced during the study). The energy analysis was conducted using dynamic simulation software after validation through energy bills; energy and economic analyses were conducted considering different external-air exchange rates. An optimal number of outdoor air changes was found to mitigate the risk of COVID-19 infection, a finding in line with the international literature. The increase in air changes with outdoor air leads to a rise in energy consumption and costs. These values were evaluated for different air conditioning systems and operational schedules. These drawbacks can be made less significant by combining interventions in the system with energy-efficiency measures applied to the building envelope. [ABSTRACT FROM AUTHOR]

In the wake of the COVID-19 pandemic, prioritizing indoor air quality has emerged as a crucial measure for preventing infections. Effective ventilation is vital in mitigating airborne pathogen transmission and maintaining a healthy indoor environment by diluting and removing infectious particles from enclosed spaces. However, increasing the supply of pathogen-free air to enhance infection control can lead to a rise in energy consumption. Nevertheless, evaluating the overall efficacy of ventilation-based infection prevention strategies while considering their energy requirements has posed challenges. This scientific paper introduces the ICEE (Infection Control's Energy Efficiency) index, a newly developed simple integrated index to assess the effectiveness of ventilation strategies in reducing infection risks while accounting for associated energy demands. The paper reviews the current understanding of ventilation strategies, their impact on infection prevention, and their corresponding energy consumption. By employing a straightforward analytical approach, this metric offers a comprehensive framework to optimize ventilation systems for both infection prevention and energy efficiency. To quantify infection risk, a simplified equation model is utilized, incorporating factors such as ventilation effectiveness and filter efficiency, in case of recirculation. Energy demand is determined using approximations and relevant values from existing literature. Reference cases are defined, distinguishing between natural and mechanically ventilated scenarios, as these reference situations influence the energy-related effects of any implemented measures. The paper outlines the methodology employed to develop the index and illustrates its applicability through exemplary measures. The proposed index yields valuable insights for the design, operation, and retrofitting of ventilation systems, enabling informed decision-making towards fostering a healthier and more sustainable built environment. [ABSTRACT FROM AUTHOR]

The heat rejected by outdoor units of split A/C conditioners can impact the ambient outdoor environment of mixed-mode buildings. Nevertheless, how this environmental impact may affect the space-conditioning energy use and indoor air pollution is poorly understood. By coupling EnergyPlus and Fluent, this study examines the effects of outdoor units' heat rejection on the building surroundings, building cooling load, and indoor PM2.5 exposure of a six-storey mixed-mode building. The building had an open-plan room on each floor, with the outdoor unit positioned below the window. The coupled model was run for a selected day when the building was cooled by air conditioning and natural ventilation. Five mixed-mode cooling strategies were simulated, reflecting different window-opening schedules, airflow rates of outdoor units, and cooling set-points. The results indicate that compared with the always-air-conditioned mode, the mixed-mode operation could significantly mitigate the negative impact of heat rejection on space-cooling energy consumption. Increasing the airflow rate of outdoor units led to a lower increase in demand for space cooling and lower indoor PM2.5 exposure. If one of the six rooms needs to be cooled to a lower temperature than the others; choosing the bottom-floor room helped achieve more energy savings and better indoor air quality. [ABSTRACT FROM AUTHOR]

Due to the necessary heat turnaround, buildings are increasingly seen as part of districts, e. g. Positive Energy Districts. Optimizing the energy efficiency of buildings is an essential part of implementing the heat turnaround. As a result, sensor/actuator systems are becoming increasingly important, both at building level and district level. Various proprietary and open standards for monitoring and control are used at building level. This heterogeneity makes it difficult to jointly optimize energy efficiency in buildings. OGC Sensorthings API (STA) is an open standard that defines a common language for sensor data and even tasking processes. In addition, KNX and LoRaWAN are available as standards for building monitoring and control. This article therefore proposes a solution that combines these standards. As proof of concept, two different buildings are equipped with KNX and LoRaWAN. Sensor data is collected in both buildings and merged centrally in a so-called building data lake based on OGC STA Sensing Part, e.g. temperature or indoor air quality. In addition, OGC STA Tasking Part is used to trigger actuator commands centrally and independently of the communication standard used in the controlled building, e. g. temperature setting of thermostats. As part of the proof of concept, it is shown how standardized sensor data can be visualized based on available visualization software, e. g. Grafana, and how the standardized actuator control level can be used for optimizations such as the night setback of heating systems. [ABSTRACT FROM AUTHOR]

In contemporary building ventilation, displacement and mixing ventilation demand high air volumes for rapid virus elimination, resulting in elevated energy consumption. To minimize the spread of viruses and decrease energy consumption for ventilation, this study employed CFD to explore the efficacy of a downward uniform flow field in impeding the transmission of aerosol particles in a high-traffic public facility, like a supermarket. The findings indicate that the downward uniform flow field proves insufficient when individuals remain static for extended periods. A wind speed of 0.1 m/s or higher becomes essential to overpower the stationary thermal plume, which disrupts this flow field. In areas with human presence, however, this technique is found to be particularly efficient since mobile heat sources do not generate a fixed thermal plume. A 0.05 m/s downward uniform flow field can settle 90% of particles within just 22 s. This flow pattern contributes to the swift settling of aerosol particles and effectively diminishes their dispersion. Employing this flow pattern in public places with increased foot traffic, like supermarkets, can lower the risk of contracting novel coronavirus without augmenting energy consumption. In order to implement the flow field in a part of the domain, a new air purification device is proposed in this study. The device combined with shelves can optimize the flow field uniformity through the MLA (PSO-SVR) algorithm and alteration of the air distribution structure. The uniformity of the final flow field increased to 0.925. The combination of data-driven MLA with CFD showed good performance in predicting the flow field uniformity. These findings offer valuable insights and practical applications for the prevention and control of respiratory diseases, particularly in post-epidemic scenarios. [ABSTRACT FROM AUTHOR]

To reduce national greenhouse gas emissions, the South Korean government has encouraged new energy businesses and implemented policies to reduce energy consumption in buildings, and aims to construct all new buildings as zero-energy buildings by 2025. According to the promotion of policies on passive houses and zero-energy buildings, the thermal insulation and airtight performance of new buildings have been further enhanced. However, to enhance indoor comfort and air quality in new airtight buildings, it is critical to secure an adequate amount of ventilation. Heat recovery ventilators (HRVs) in South Korea have been used for more than 20 years as high-efficiency energy equipment; however, the high-efficiency standard 20 years ago (cooling efficiency 45%, heating efficiency 70%) is still being employed without any change. Most HRVs in the Korean market either meet or exceed this standard. This study examined HRV performance changes from 2010 to 2020 based on the data of 847 HRV performance certifications given by a certification agency. It also analyzed how institutional strategies and related laws contributed to the enhancement of such performance. As HRVs in South Korea are only required to satisfy the pre-defined efficiency criteria, the development and use of HRVs focus more on cost reduction rather than efficiency enhancement. Under such market conditions, it is challenging to research and design highly efficient HRVs along with customer satisfaction. If better market conditions are offered that would welcome HRVs with higher efficiency, the development of better HRVs, as compared to those analyzed in this research study, would be possible. [ABSTRACT FROM AUTHOR]

Outdoor environment exchanges heat with indoor environment, enabling pollutants to infiltrate indoors, affecting buildings' energy efficiency, comfort, and indoor air quality. Investigating the impact of the outdoor environment on the indoor thermal environment is crucial. Firstly, this paper reviews the coupling method to link the outdoor environment with the indoor environment. Secondly, it examines the impact of the outdoor physical environment, including neighboring buildings, greening, road surface, water body, and sky, on the indoor thermal environment. During the hottest summer, an increase of 17% in trees can reduce indoor temperature by 1.1 °C. Thirdly, the impact of weather conditions, including outdoor temperature, outdoor humidity, external wind, global warming, extreme weather conditions, and solar radiation, on the indoor thermal environment is studied. Due to global warming, cooling energy consumption and heating energy consumption in 2050 could increase by 223% to 1050%, and heating demand could decrease by 36% to 58%. Finally, the impact of outdoor air pollution on indoor environment and energy consumption is analyzed. For every 75 μg/m3 increase in PM2.5 concentration, average power consumption could increase by 11.2%. Recommendations for future research are provided. This study contributes to the understanding of the outdoor–indoor thermal relationship and offers insights into enhancing indoor thermal comfort and reducing building energy consumption. [ABSTRACT FROM AUTHOR]

Nowadays, indoor air quality (IAQ) and the energy performance of buildings are two main scientific and technical challenges because they are in direct connection with human health and the depletion of energy resources. In this study, we analyzed the influence of an outdoor air flow introduced through a mechanical ventilation system, focusing on the two aforementioned topics. A standardized ventilation rate (25 m3/h/person) led to an increase in the indoor O3 concentration (from 5 μg/m3 to 50 μg/m3) and, simultaneously, to a decrease in the indoor CO2 concentration (from 2000 mg/m3 to 800 mg/m3), a decrease in the PM2.5 concentration (from 300 μg/m3 to 150 μg/m3), and the maintenance of a constant indoor HCHO concentration. In our study, a new, single indoor air quality index, IIAQ, is proposed. This new index presents different implications: on the one hand, it has the ability to simultaneously take into account several pollutant species, and on the other hand, it can prioritize the ventilation strategy that responds to the extreme values of a certain pollutant. Moreover, indoor air quality classes were elaborated, similar to energy classes. The possibility of using this new index simultaneously with energy consumption may lead to ventilation strategies that are adaptative to dynamic outdoor pollutant concentrations.

The COVID-19 pandemic and global shutdown and work-from-home order for non-essential businesses and employees led to a substantial decline in energy usage in the commercial building sector. However, the magnitude of decline was not equivalent to what would be expected for unoccupied spaces. The energy performance of low/unoccupied commercial buildings, particularly in the context of new minimum requirements to maintain indoor air quality, is an intriguing research question. In this study, we developed a numerical model that measures electricity usage sensitivity to occupancy (ESTO) where we compare the business-as-usual energy performance with unoccupied energy performance. Two years of COVID-time (in addition to a pre-COVID control year) hourly energy use (electricity (plug loads, lighting, and fans), heating, and cooling) using data from 35 commercial buildings (i.e., buildings with HVAC and other building systems typical of commercial rather than residential buildings) are analyzed to quantify those changes. A change point model is used to assess thermal load intensities, change point temperature, and off-season unoccupied baseloads. Finally, we suggest a generic framework for building scoring based on selected performance parameters. Results indicate that the suggested scoring system is robust and replicable and is reliable for ranking buildings within a given portfolio from best- to worst- performing, thus prioritizing buildings that are best candidates for retrofits. [ABSTRACT FROM AUTHOR]

The healthcare industry significantly impacts the environment due to its high usage of energy and natural resources and the associated waste generation. This study applied a cradle-to-grave Life Cycle Sustainability Assessment (LCSA) approach to assess the environmental and social life cycles of public hospitals. One hundred twenty-four public hospitals were selected for the current study; their sustainability performance was compared with those certified by Leadership in Energy and Environmental Design (LEED). The comparison revealed several factors contributing to the poor sustainability performance of public hospitals. These include inadequate management, substandard planning, political interference, insufficient staffing and funding, high energy consumption, high expenses, inconsistent healthcare policies, and conventional building designs. System thinking was leveraged, and a causal loop diagram (CLD) was developed to visualize the interdependency of the identified indicators of LCSA. Based on the findings of the study, a policy framework is proposed to guide the development of sustainable healthcare buildings. The framework includes using eco-friendly materials and techniques in construction, harnessing solar energy, improving hospital management practices, promoting public awareness about sustainability, conserving energy and water, and adopting sustainable waste management and transportation. Additionally, it emphasizes addressing social issues such as improving indoor air quality, thermal comfort, lighting, acoustics, patient safety, and security and ensuring that healthcare services are accessible and affordable. This study contributes to the literature on sustainable healthcare buildings by providing a practical policy framework for achieving sustainability in the healthcare sector. [ABSTRACT FROM AUTHOR]

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Material selection is a challenging process in which several parameters should be considered for green-certified projects. Hence, this study investigates the dynamics of sustainable material selection (SMS) across the project life cycle using system thinking. A dynamic model was developed based on the Leadership in Energy and Environmental Design where relevant environmental categories and credits were represented, and their dependency coefficients (DCs) were computed. This pinpointed the effect of SMS on the point-accrual pattern across project phases, showing that the high leverage points were demonstrated for the operation phase. The result showed that SMS extended beyond the efficient use of materials, which indicated a DC of 100% in the Materials and Resources category to affect other sustainable categories, i.e., the indoor environmental quality, energy efficiency, and sustainability of the project site comprised 68.8%, 57.6%, and 50% of DCs, respectively. Thus, optimal SMS could earn the project 48% of the total possible points, putting it in the 'Certified' level. Accordingly, the proposed model can be used to evaluate the level of certification as well as the building performance therein. [ABSTRACT FROM AUTHOR]

Currently, the optimization of thermal energy consumption in buildings is considered a suitable alternative in the construction of new buildings, as a result of which the overall energy efficiency of the building increases. Thus, this study examined the efficiency and efficacy of different building renovation packages conducted across several buildings in Latvia and in Lithuania (across a larger building stock). In the first section of this study, 13 multi-apartment residential houses with 3 building renovation packages have been investigated in the city of Daugavpils, Latvia, in order to determine the actual reduction in heat energy consumption across each of the renovation implementation packages. The study findings indicate that changes in Latvian building regulations regarding insulation thickness did not significantly impact thermal energy consumption in fully renovated buildings. However, the combination of facade renovations, upgraded heating systems, and improved ventilation systems resulted in substantial energy savings, with an average reduction of 50.59% in thermal energy consumption for space heating across the reviewed multi-apartment residential building stock. In the following section of this study, the impact of the Energy Performance of Buildings Directive (EPBD) on building energy efficiency in Lithuania has been examined. The results show that over a 10-year period in the 2000s, Lithuanian building stock experienced a 20% increase in energy efficiency, followed by an additional 6.3% increase between 2010 and 2016. The mandatory requirement for renovated buildings to achieve a minimum energy efficiency class has resulted in significant reductions in energy consumption for heating purposes. The findings underscore the effectiveness of building renovation packages and the EPBD regulations in enhancing energy efficiency and promoting sustainable building practices. The importance of heat metering, consideration of indoor air temperature, and the need to address indoor air quality during renovations were also highlighted. [ABSTRACT FROM AUTHOR]

In the current context of joint efforts towards the decarbonisation of buildings, integrating occupants' comfort and health with latest technological advancements for energy efficiency is at the center of the latest development of research, policies and professional practice. Radiant systems are encountering great success since the low-thickness systems can also be used in renovation projects for both heating and cooling, while guaranteeing optimal comfort. However, dehumidification is often required for optimal radiant cooling operation with no condensation risks, and the great potential of mechanical ventilation systems to optimally address the needs for dehumidification, air renewal, health and energy efficiency appears to be far from its full exploitation in the post-COVID-19 era. The present paper aims at providing a quantification of the energy and financial impacts of the implementation of a controlled mechanical ventilation system (CMV) coupled to a radiant system in a typical residential case study building in Italy. The results show that the sole CMV may decrease primary energy demand and energy costs by more than 30% and contribute to an increase in the smart readiness of the building by 8%, but further incentive policies must be developed to cover the still high investment and maintenance cost. [ABSTRACT FROM AUTHOR]

This paper discusses the use of advanced monitoring techniques for optimal control of building management systems (BMS) in public buildings, with the objective of guaranteeing the appropriate air quality, minimizing energy consumption. The paper reviews the current state of BMS technologies, and the challenges associated with reducing energy consumption in public buildings. It then discusses the potential benefits of advanced monitoring techniques and their application in BMS, including improved energy efficiency, occupant comfort, and indoor air quality. The analysis conducted highlights the challenges in establishing a direct relationship between monitoring data and HVAC system control, emphasizing the potential of Machine Learning algorithms in addressing this issue. [ABSTRACT FROM AUTHOR]

The physical factors of building performance in a school building must be determined to meet the users' basic requirement of comfort level. The disruption of physical factors such as ventilation, lighting, or thermal may constitute to reduce the productivity and efficiency among users. Thus, Post Occupancy Evaluation (POE) is a significant tool to indicate the level of satisfaction and occupants' comfort in ensuring the current issues mainly related to physical aspects such as indoor environmental quality, space utilization, energy efficiency, and so forth. Therefore, the primary purpose of this study is to assess the satisfaction level of school building users in Malaysia, including students, teachers, and staff to improve the quality of the indoor environment in a school building as the leading learning space for the future generation. The interview was conducted with 12 participants in determining the satisfaction level of building performance assessment on school buildings. Next, the survey instrument was distributed to 224 respondents in 7 different schools, to evaluate the awareness level of POE in current practice and to analyse the physical criteria to conduct the evaluation standards on school buildings in Malaysia. This study concludes that POE is the most accurate approach to estimate the quality of building performance, especially for school buildings. Also, it should be emphasized as a continuous routine of physical environment evaluation or a periodic assessment of school buildings. [ABSTRACT FROM AUTHOR]

Research on nearly zero-energy buildings has addressed mainly the aspects of energy saving or technical and economic optimization, while some studies have been conducted on comfort and indoor air quality. However, the potential problems that may arise in low-energy buildings during the operational phase, and especially the risk of fungal growth, which can deteriorate the indoor environment and pose a health risk to the occupants, are yet to be extensively investigated. The present work intends to analyze previous research on microbial contamination in zero-energy buildings in order to identify the possible risks that may lead to fungal formation and the possible strategies to prevent the proliferation of molds. The methodology is based on a systematic literature review and subsequent critical analysis to outline perspectives on this topic. The main results indicate that high envelope insulation and inadequate ventilation are the leading causes of fungal growth in energy-efficient buildings. The need for more detailed regulation in this area is also highlighted. The study's outcomes underline the need for more attention to be paid to the design and management of zero-energy buildings, aiming to achieve the reduction in energy demands while ensuring the occupants' well-being. [ABSTRACT FROM AUTHOR]