A Healthy, Energy-Efficient and Comfortable Indoor Environment, a Review

The Working Environment in Primary Healthcare Outpatient Facilities: Assessment of Physical Factors and Health Professionals' Perceptions of Working Environment Conditions

The objectives of this study were to assess the adequacy of physical parameters/factors (temperature, relative humidity, noise, and illuminance levels) of the work environment in PHC facilities, to evaluate the association between the adequacy of these measured physical parameters and the physical characteristics of the PHC facilities and their surroundings and to assess the association between health professionals' perceptions about exposure to physical risks in the PHC work environment and the adequacy of physical parameters measured in the same facilities. The study monitored 23 PHC facilities in southern Brazil and interviewed 210 health professionals. Data analysis involved Pearson's chi-square, Fisher's exact test, Spearman's correlation, and multivariate linear regression analysis was used to control for confounding factors. The significance level was set at 5% (p ≤ 0.05). The combination of temperature and relative humidity presented thermal comfort levels outside the adopted criteria for adequacy in consultation (outdoor relative humidity, p = 0.013) and procedure rooms (front door open, p = 0.034). Inadequate sound comfort (noise) levels in the morning shift were found in the vaccination (front door open, p = 0.021) and consultation rooms (movement of people, p = 0.016). In PHC facilities where reception rooms had insufficient lighting, internal curtains were opened less frequently (p = 0.047). The analysis of health professionals' perceptions of physical factors demonstrated that physicians more frequently perceive the physical risk of temperature and humidity (p = 0.044). The higher the number of nurses (p = 0.004) and oral health technicians in the PHC facilities (p = 0.031), the greater the general percentage of adequacy of monitored physical parameters. It was also confirmed that the higher the perception of moderate or severe physical risk among health professionals, the lower the general percentage of the adequacy of the physical parameters of the work environment of the PHC facilities evaluated (rs = -0.450, p = 0.031). This study's evidence contributes to a better understanding of physical conditions and future occupational interventions to ensure the comfort, safety, and well-being of PHC workers.

The residential application of chain recooling energy recovery ventilator system in a hot and humid climate

The Energy Recovery Ventilator (ERV) is proven efficient for residential ventilation applications. Yet, certain drawbacks, including a more confined space due to descended ceiling, a lengthy accompanying duct system, and over-ventilation issues that result in extensive energy consumption, need to be addressed. In this study, a novel Chain Recooling Energy Recovery Ventilator (CR-ERV) system is proposed to replace the typical ERV system design to solve the shortcomings above. By conducting an experiment on a three-bedroom condo in a hot and humid climate, it was found that compared to the natural ventilation strategy, the proposed system can help reduce the mean indoor carbon dioxide (CO₂) concentration from 976 to 677 ppm and PM_2.5 concentration from 6.4 to 4.1 μg/m³, representing a 29% and 34% reduction, respectively. From the regulatory perspective, only 64.4% of the natural-ventilated hours have a CO₂ concentration below the 1000 ppm limit per the local air quality Act. This fraction can be improved to 99% after adopting the proposed ventilation system. All these benefits come at the cost of a slight 2.3% increase in electricity consumption. In summary, the proposed system is proven efficient, and its implementation is fairly straightforward and economical; thus might be worth integrating into future residential building projects.

Hazard Evaluation of Indoor Air Quality in Bank Offices

IAQ is a crucial factor affecting the health, comfort, and productivity of workers, particularly those working in enclosed spaces like bank offices. This study aimed to evaluate the IAQ of a bank office’s operational area and vault by analyzing concentrations of CO2, TVOC, PM10, and PM2.5, as well as temperature, relative humidity, and air movement. Two different ventilation systems were compared to assess their impact on IAQ. The acquired data were statistically analyzed using mean comparison t-tests and hazard ratio analysis. The results revealed that indoor concentrations of PM2.5 and CO2 significantly contribute to the total hazard ratio, indicating the need to reduce their levels below reference values. The study also found that the ventilation system significantly affects indoor air quality, and concentrations of TVOC, CO2, PM10, and PM2.5 in the air are considerable. Significantly, the study found that bank offices with split unit air-conditioners had the highest mean CO2 levels, indicating poor ventilation. Overall, the study reveals that the building, activities, and ventilation in bank offices have a profound influence on IAQ parameters, primarily PM2.5 and CO2. Further research is required to formulate strategies for enhancing IAQ in these settings.

Acoustic Performance of Floors Made of Composite Panels

Airborne and impact sound insulation of composite panels arranged in different configurations were investigated in this study. The use of Fiber Reinforced Polymers (FRPs) in the building industry is growing; however, poor acoustic performance is a critical issue for their general employment in residential buildings. The study aimed to investigate possible methods of improvement. The principal research question involved the development of a composite floor satisfying acoustic expectations in dwellings. The study was based on the results of laboratory measurements. The airborne sound insulation of single panels was too low to meet any requirements. The double structure improved the sound insulation radically at middle and high frequencies but the single number values were still not satisfactory. Finally, the panel equipped with the suspended ceiling and floating screed achieved adequate level of performance. Regarding impact sound insulation, the lightweight floor coverings were ineffective and they even enhanced sound transmission in the middle frequency range. Heavy floating screeds behaved much better but the improvement was too small to satisfy acoustic requirements in residential buildings. The composite floor with a dry floating screed and a suspended ceiling appeared satisfactory with respect to airborne and impact sound insulation; the single number values were R_w (C; C_tr) = 61 (-2; -7) dB, and L_n,w = 49 dB, respectively. The results and conclusions outline directions for further development of an effective floor structure.

Patterns of Perceived Indoor Environment in Danish Homes

The indoor environment is composed of several exposures existing simultaneously. Therefore, it might be useful to combine exposures into common combined measures when used to assess the association with health. The aim of our study was to identify patterns of the perceived indoor environment. Data from the Danish Health and Morbidity Survey in the year 2000 were used. The perceived indoor environment was assessed using a questionnaire (e.g., annoyances from noise, draught, and stuffy air; 13 items in total). Factor analysis was used to explore the structure of relationships between these 13 items. Furthermore, groups of individuals with similar perceived indoor environment were identified using latent class analysis. A total of 16,688 individuals ≥16 years participated. Their median age was 46 years. Four factors were extracted from the factor analysis. The factors were characterized by: (1) a mixture of items, (2) temperature, (3) traffic, and (4) neighbor noise. Moreover, three groups of individuals sharing the same perception of their indoor environment were identified. They were characterized by: a low (n = 14,829), moderate (n = 980), and large number of annoyances (n = 879). Observational studies need to take this correlation and clustering of perceived annoyances into account when studying associations between the indoor environment and health.

Displacement ventilation to avoid COVID-19 transmission through offices

Respiratory infections such as COVID-19 can be spread by respiratory droplets with a diameter larger than 5-10 μ m or by droplet nuclei with a diameter smaller than 5 μ m . Besides wearing masks, fresh air should be supplied frequently in closed rooms to avoid infections. Constructing and operating new isolation rooms require time, money, and maintenance cost, which are scarce in the current pandemic and in many communities. Displacement ventilation may be a feasible and secure option in temporary hospitals and other buildings to control the disease. This paper investigates using CFD simulations how displacement ventilation systems can deliver high air quality, and thermal comfort and minimize the risk of COVID-19 infection in enclosed spaces.

Effect of Architectural Building Design Parameters on Thermal Comfort and Energy Consumption in Higher Education Buildings

It has been challenging for designers to identify the appropriate design parameters that would reduce building energy consumption while achieving thermal comfort for building occupants. This study aims to determine the most important architectural building design parameters (ABDPs) that can increase thermal comfort and reduce energy use in educational buildings. The effect of 15 ABDPs in an Australian educational lecture theatre and their variabilities on energy consumption and students’ thermal comfort for each parameter were analysed using Monte Carlo (MC) techniques. Two thousand simulations for every input parameter were performed based on the selected distribution using the Latin hypercube sampling (LHS) technique. Sensitivity analyses (SA) and uncertainty analyses (UA) were used to assess the most important ABDPs in terms of thermal discomfort hours and energy consumption. The study found that the ABDPs, such as cooling set-point temperatures and roof construction, significantly reduce the operative temperature by up to 14.2% and 20.0%, respectively. Consequently, these reductions could significantly shorten the thermal discomfort hours, thereby reducing energy consumption by 43.7% and 41.0%, respectively. The findings of this study enable building designers to identify which ABDPs have a substantial impact on thermal comfort and energy consumption.

Profiling office workers based on their self-reported preferences of indoor environmental quality and psychosocial comfort at their workplace during COVID-19

Due to the COVID-19 pandemic, a large number of office workers were required to conduct their work from home. Little is known about the indoor environmental quality (IEQ) preferences and psychosocial comfort preferences of staff working from home. Therefore this study aimed to cluster office workers working at home based on their self-reported preferences for IEQ and psychosocial comfort at their most used workspace and to identify these preferences and needs of workers during the COVID-19 pandemic. A questionnaire was administered to employees of ten offices in the Netherlands, and the 502 respondents were clustered with two models by using TwoStep cluster analysis. The first model was based on variables related to IEQ preferences, while the second was to psychosocial comfort preferences. The analysis revealed four IEQ clusters and six psychosocial comfort clusters. Comparison of these results with other similar studies proposed that the prevalence of anxiety, depression, migraine, and rhinitis, increased for this population during the work-from-home period of the pandemic. Further results suggest that both IEQ and psychosocial comfort preferences are situation- and gender-dependent.

Designing Post COVID-19 Buildings: Approaches for Achieving Healthy Buildings

The COVID-19 pandemic forced the accessibility, social gathering, lifestyle, and working environment to be changed to reduce the infection. Coronavirus spreads between people in several different ways. Small liquid particles (aerosols, respiratory droplets) from an infected person are transmitted through air and surfaces that are in contact with humans. Reducing transmission through modified heating, ventilation, and air conditioning (HVAC) systems and building design are potential solutions. A comprehensive review of the engineering control preventive measures to mitigate COVID-19 spread, healthy building design, and material was carried out. The current state-of-the-art engineering control preventive measures presented include ultraviolet germicidal irradiation (UVGI), bipolar ionization, vertical gardening, and indoor plants. They have potential to improve the indoor air quality. In addition, this article presents building design with materials (e.g., copper alloys, anti-microbial paintings) and smart technologies (e.g., automation, voice control, and artificial intelligence-based facial recognition) to mitigate the infections of communicable diseases.

Structural Optimization and Application Research of Alkali-Activated Slag Ceramsite Compound Insulation Block Based on Finite Element Method

The research and application of new wall materials have been attracting increasing attention owing to the continuous promotion of sustainable development in the building industry. An alkali-activated slag ceramsite compound insulation block (AASCCIB) is used as the research object. Based on the finite element method, the effects of different numbers of hole rows and hole ratios on the thermal and mechanical performances of AASCCIBs are analyzed using ANSYS CFX. On this basis, the AASCCIB with the optimal comprehensive performance is determined by a multi-objective optimization analysis. Finally, the improvement effect of the AASCCIB wall on the indoor thermal environment relative to an ordinary block (OB) wall is quantitatively analyzed using ANSYS CFX. The results show that the von Mises equivalent stress and heat transfer coefficient of the AASCCIB decrease with the increase in the hole ratio when the hole shape and number of hole rows are constant. AASCCIB B1 has the optimal comprehensive performance among six AASCCIBs, with the heat transfer coefficient and average von Mises equivalent stress of 0.446 W/(m2∙K) and 9.52 MPa, respectively. Compared with the indoor lowest and average temperatures of the building with the OB wall, those of the building with the AASCCIB wall increased by at least 1.39 and 0.82 °C on the winter solstice, respectively. The indoor temperature difference decreased by at least 0.83 °C. In addition, the indoor highest temperature, average temperature, and temperature difference decreased by at least 1.75, 0.79, and 1.89 °C on the summer solstice, respectively.

Towards Net Zero Carbon Economy: Improving the Sustainability of Existing Industrial Infrastructures in the UK

To comply with the new net zero greenhouse gas emissions (GHGs) target set by the United Kingdom government by 2050, different sectors including the industrial sector are required to take action to achieve this target. Improving the building envelope and production of clean energy on site are among the activities that should be considered by businesses to reduce their carbon emissions. This research analysis the current energy performance and carbon dioxide (CO2) emissions of an industrial building in Liverpool, UK utilizing the Integrated Environmental Solutions Virtual Environment (IESVE) software modeling. Then it has proposed some methods for improving the current performance and reduce the carbon footprint of the building. The results indicated that the installation of wall and floor insulation could decrease the energy usage and CO2 emissions of the building by about 56.39%. Additionally, the production of clean energy on site using solar photovoltaic (PV) panels could reduce the annual CO2 emissions by up to 16%. Furthermore, this research provided some figures about offsetting the rest of CO2 emissions using different international offsetting schemes to achieve carbon neutrality of the building.

HVAC Energy Saving Strategies for Public Buildings Based on Heat Pumps and Demand Controlled Ventilation

The paper analyzes and compares the perspectives for reducing the energy consumption associated to the operation of Heating Ventilation and Air Conditioning system for climatic control of large-size non-residential buildings. Three different control strategies are considered comparing the use of boiler and heat pumps as heating systems and analyzing the use of demand-controlled ventilation, operating on the effective occupancy of the building. The control strategies are applied to two different educational buildings with shapes representative of typical educational structures. The results of the analysis show how the energy consumption can be reduced up to 70%, shifting from the actual values of the energy intensity of over 300 kWh/m2 for year to values of less than 100 kWh/m2 per year. The significance of the energy savings achieved in such different buildings has led to the identification of a possible benchmark for HVAC systems in the next future years which could help reach the environmental targets in this sector.

The Comfort Map—A Possible Tool for Increasing Personal Comfort in Office Workplaces

Previous studies have shown that indoor environmental quality (IEQ) parameters may have a considerable effect on office employees’ comfort, health and performance. Therefore, we initiated a research program to help occupants identify IEQ parameters they perceive as risk factors for their health in an office and enhance their comfort levels in an office environment. Since we assumed that office employees might have different indoor environmental quality expectations related to their work area and that these differences could be measured, our objective was to develop an office ‘comfort map’ based on occupants’ individual IEQ preferences. Thus, the goal of the comfort map would be to help tailor office spaces to their occupants’ health and comfort expectations. The comfort survey was developed to assess the comfort-related opinions of the occupants, based on IEQ parameters (visual comfort, acoustic comfort, air quality and thermal comfort) of a chosen open-plan office building. The survey also assessed the degree to which the given IEQ parameter was considered a health risk factor by occupants or caused a negative comfort sensation for them. The survey was filled in by 216 occupants. The answers were then analyzed with the help of a frequency table depicting relative frequency. The measurements of IEQ parameters took place in an open-plan office in the chosen office building (a Hungarian subsidiary’s office building belonging to an international company in Budapest). The occupants had different opinions regarding the perceived effects of the IEQ parameters on their health and comfort. Almost two-thirds of the respondents (64.8%) were dissatisfied with the adjustability of the noises and sounds IEQ parameter at their workstation. Furthermore, half of the respondents (50.1%) were dissatisfied with the adjustability of ventilation. Most of the occupants (45.8%) considered noises and sounds as the IEQ parameter that had a negative effect on their health. There were also IEQ differences between different areas of the office space. Based on these results, a comfort map was developed for the office. The comfort map contains information about the IEQ characteristics of each workstation by depicting the thermal comfort, carbon dioxide, visual comfort and acoustic comfort characteristics of a given workstation on a relative scale. Based on the thermal, air, acoustic, and lighting differences between the workstations, occupants can select their preferred workstations when a desk-sharing system works. Although still in its pilot phase, the comfort map could increase the chances for office employees to find the workstation best suited to their IEQ expectations. This could improve occupants’ overall comfort level, which could in turn enhance occupants’ productivity and mental as well as physical health.

Multi-Objective Optimization of HVAC Operation for Balancing Energy Use and Occupant Comfort in Educational Buildings

The paper provides a methodology for the optimal control of heating, ventilation, and air conditioning (HVAC) systems used in public buildings, with the purpose of obtaining high comfort and safety standards along with energy efficiency. The combination of the two concurrent objectives of minimizing energy use and guaranteeing high standards of occupant comfort is obtained by means of multi-objective optimization, in which a comfort model is combined along with a dynamic energy model of the building. The use of dynamic setpoints for the HVAC and the inclusion of comfort indicators represent a step forward, compared to the current design and operation procedures suggested by technical standards. The utilization of the proposed methodology is tested with reference to a case study, represented by an academic building used by the University of Pisa for educational purposes, whose extensive and variable occupancy can help to emphasize the importance of comfort in the operation of HVAC systems in different climatic conditions and with different occupancy profiles. We show how this optimization brings interesting results in terms of energy-saving (up to 30%), obtaining an increased comfort level (of more than 25%) compared to the operating conditions suggested by technical standards.

3D Variables Requirements for Property Valuation Modeling Based on the Integration of BIM and CIM

The growing rate of urbanization and vertical urban development has aroused the significance of geo-related variables for property units disposed vertically within the same building. Among these, 3D indoor physical and outdoor environmental variables are impacting the property value for each building unit. However, in the literature, the identified 3D variables, by using hedonic pricing models (HPM) for property valuation, are mainly restricted to 3D visualization. Their use in 3D simulation for an accurate evaluation of the property value is still limited. Furthermore, their value is often defined for a specific valuation purpose (e.g., taxation). This paper aims to investigate 3D variables with a significant impact on property value, to combine them with 3D technical requirements and to be integrated in a future valuation model. Moreover, their 3D spatial and non-spatial elements are analyzed to identify which variables can be provided from 3D city models and building scale elements. To accomplish this, the potential of 3D building information modeling (BIM) and city information modeling (CIM) in property valuation is examined. From indoors; BIM/IFC (Industry Foundation Classes) models are the main data sources for structural and living quality variables. While from outdoors, environmental variables and the surrounding building’s information are provided from 3D city models (CityGML).

Impact Assessment in the Process of Propagating Climate Change Uncertainties into Building Energy Use

Buildings are subject to significant stresses due to climate change and design strategies for climate resilient buildings are rife with uncertainties which could make interpreting energy use distributions difficult and questionable. This study intends to enhance a robust and credible estimate of the uncertainties and interpretations of building energy performance under climate change. A four-step climate uncertainty propagation approach which propagates downscaled future weather file uncertainties into building energy use is examined. The four-step approach integrates dynamic building simulation, fitting a distribution to average annual weather variables, regression model (between average annual weather variables and energy use) and random sampling. The impact of fitting different distributions to the weather variable (such as Normal, Beta, Weibull, etc.) and regression models (Multiple Linear and Principal Component Regression) of the uncertainty propagation method on cooling and heating energy use distribution for a sample reference office building is evaluated. Results show selecting a full principal component regression model following a best-fit distribution for each principal component of the weather variables can reduce the variation of the output energy distribution compared to simulated data. The results offer a way of understanding compound building energy use distributions and parsing the uncertain nature of climate projections.

Biometric Data as Real-Time Measure of Physiological Reactions to Environmental Stimuli in the Built Environment

The physiological and cognitive effects of environmental stimuli from the built environment on humans have been studied for more than a century, over short time frames in terms of comfort, and over long-time frames in terms of health and wellbeing. The strong interdependence of objective and subjective factors in these fields of study has traditionally involved the necessity to rely on a number of qualitative sources of information, as self-report variables, which however, raise criticisms concerning their reliability and precision. Recent advancements in sensing technology and data processing methodologies have strongly contributed towards a renewed interest in biometric data as a potential high-precision tool to study the physiological effects of selected stimuli on humans using more objective and real-time measures. Within this context, this review reports on a broader spectrum of available and advanced biosensing techniques used in the fields of building engineering, human physiology, neurology, and psychology. The interaction and interdependence between (i) indoor environmental parameters and (ii) biosignals identifying human physiological response to the environmental stressors are systematically explored. Online databases ScienceDirect, Scopus, MDPI and ResearchGate were scanned to gather all relevant publications in the last 20 years, identifying and listing tools and methods of biometric data collection, assessing the potentials and drawbacks of the most relevant techniques. The review aims to support the introduction of biomedical signals as a tool for understanding the physiological aspects of indoor comfort in the view of achieving an improved balance between human resilience and building resilience, addressing human indoor health as well as energetic and environmental building performance.

Balancing User Comfort and Energy Efficiency in Public Buildings through Social Interaction by ICT Systems

Energy efficiency, indoor environmental quality, and comfort in public buildings has received increasing attention in recent years as it can contribute to maintaining safety conditions and to the reduction of conventional fuels consumption, energy costs for building owners, and greenhouse gas emissions. People are an integral part of any building energetic ecosystem as, according to some estimates, they spend a great part of their life in indoor spaces. On one side, occupants are responsible for the energy consumption of the building and for this reason the “psychology of energy saving” has received attention since the 70s up to recent results. On the other hand, strategies for energy efficiency should not jeopardize occupants’ health and quality of life. While general awareness of the value of environmental variables has increased in the last few years, this interest has recently been further exacerbated by the spreading of the well-known COVID-19 pandemic. In fact, as most countries have started planning post-lock-down activities, there is a growing concern regarding how social distancing measures can be enforced in shared buildings and strict indoor air quality control can prevent airborne virus transmission in crowded spaces. The paper discusses the perspectives of increasing the level of social interaction of building users through the systematic use of Information and Communication Technologies (ICT), and in particular, some specific platforms. The ICT system, taking information from the occupants in a concerted way, can be an important instrument to collect data, coming both from physical sensors and from people to develop a multi-objective control strategy for the Heating, Ventilation, and Air Cooling (HVAC) systems in order to obtain energy savings whilst balancing user comfort and healthy conditions.

A Comparative Simulation Study of the Thermal Performances of the Building Envelope Wall Materials in the Tropics

The building walls which form the major part of the building envelope thermally interact with the changing surrounding environment throughout the day influencing the indoor thermal comfort of the space. This paper aims at assessing in detail the different aspects (thermophysical properties, thickness, exposure to solar heat gain, etc.) of opaque building wall materials affecting the indoor thermal environment and energy efficiency of the buildings in tropical climate (in the summer and winter days) by conducting simplified simulation analysis using the Integrated Environmental Solutions Virtual Environment (IES-VE) program. Besides, the thermal efficiency of a number of selected wall materials with different thermal properties and wall configurations was analysed to determine the most optimal option for the studied climate. This study first developed the conditions for parametric simulation analysis and then addressed selected findings by comparing the thermal responses of the materials to moderate outdoor temperature and energy-saving potential. While energy consumption estimation for a complete operational building is a complex method by which the performance of the wall materials cannot be properly defined, as a result, this simplistic simulation approach can guide the designers to preliminary analyse the different building wall materials in order to select the best thermal efficiency solution.

Assessment of Thermal Comfort in the Intelligent Buildings in View of Providing High Quality Indoor Environment

The paper analyses the indoor environment in two modern intelligent buildings located in Poland. Measurements of air and globe temperatures, relative humidity and carbon dioxide concentration in 117 rooms carried out in the space of 1.5 years were presented. Thermal comfort of the occupants has been investigated using a questionnaire survey. Based on 1369 questionnaires, thermal sensation, acceptability and preference votes were analysed in view of their interdependency as well as their dependency on operative temperature, which proved to be very strong. It has been found that the respondents did not completely rate thermal comfort and indoor environment quality as very high, although the overwhelming sensations were positive. Apart from the operation of heating, ventilation and air conditioning (HVAC) systems, this might have also been the cause of individual human factors, such as body mass index, as tested in the study, or the finding that people were generally in favour of a warmer environment. Moreover, thermal environment proved to be the most important element for ensuring the well-being of the occupants.

Evaluation of the Visual Stimuli on Personal Thermal Comfort Perception in Real and Virtual Environments Using Machine Learning Approaches

Personal Thermal Comfort models consider personal user feedback as a target value. The growing development of integrated “smart” devices following the concept of the Internet of Things and data-processing algorithms based on Machine Learning techniques allows developing promising frameworks to reach the best level of indoor thermal comfort closest to the real needs of users. The article investigates the potential of a new approach aiming at evaluating the effect of visual stimuli on personal thermal comfort perception through a comparison of 25 participants’ feedback exposed to a real scenario in a test cell and the same environment reproduced in Virtual Reality. The users’ biometric data and feedback about their thermal perception along with environmental parameters are collected in a dataset and managed with different Machine Learning techniques. The most suitable algorithm, among those selected, and the influential variables to predict the Personal Thermal Comfort Perception are identified. The Extra Trees classifier emerged as the most useful algorithm in this specific case. In real and virtual scenarios, the most important variables that allow predicting the target value are identified with an average accuracy higher than 0.99.

The Influence of Insulating Layers on the Acoustic Performance of Lightweight Frame Floors Intended for Use in Residential Buildings

The acoustic performance of floors plays a primary role in the total quality rating of a residential building. The sound insulation of lightweight frame floors, which are increasingly being used in housing, depends on a number of factors and technical details. In effect, the sound transmission scheme is distinctly more complicated than in the case of homogeneous massive partitions. The aim of the study was to develop effective insulating layers of lightweight floors intended for use in residential buildings. The floor system should satisfy legal requirements in terms of airborne and impact sound insulation. The research was based on laboratory measurements taken in a standard test facility. Ten different models of wood and metal floors were considered. The acoustic performance of their basic structure was insufficient; however, the application of effective floating floors and suspended ceilings improved it greatly and succeeded in potential meeting requirements and satisfying most inhabitants’ expectations. The results demonstrate how different lightweight floor components influence the acoustic performance of the floor and how the insulating layers cooperate when applied together. The findings will be useful in working on a new floor design and optimizing its structure in terms of acoustics.

A BIM-LCA Approach for Estimating the Greenhouse Gas Emissions of Large-Scale Public Buildings: A Case Study

Exiting green building assessment standards sometimes cannot work well for large-scale public buildings due to insufficient attention to the operation and maintenance stage. This paper combines the theory of life cycle assessment (LCA) and building information modeling (BIM) technology, thereby proposing a green building assessment method by calculating the greenhouse gas emissions (GGE) of buildings from cradle to grave. Life cycle GGE (LCGGE) can be divided into three parts, including the materialization stage, the operation and maintenance stage, and the demolition stage. Two pieces of BIM software (Revit and Designbuilder) are applied in this study. A museum in Guangdong, China, with a hot summer and warm winter is selected for a case study. The results show that BIM can provide a rich source of needed engineering information for LCA. In addition, the operation and maintenance stage plays the most important role in the GGE reduction of a building throughout the whole life cycle. This research contributes to the knowledge body concerning green buildings and sustainable construction. It helps to achieve the reduction of GGE over the whole life cycle of a building. This is pertinent to contractors, homebuyers, and governments who are constantly seeking ways to achieve a low-carbon economy.

Indoor Environmental Quality Analysis for Optimizing Energy Consumptions Varying Air Ventilation Rates

The energy refurbishment of the existing building heritage is one of the pillars of Italian energy policy. Aiming for energy efficiency and energy saving in end uses, there are wide and diversified improvement strategies, which include interventions on the building envelope and Heating, Ventilation, and Air Conditioning (HVAC) systems, with the introduction of renewable energy sources. The research aims at evaluating the building energy consumptions and Indoor Environmental Quality (IEQ), varying the airflow rates handled by the HVAC system. A Case Study (the Aula Magna of a university building) is analysed; an in-situ monitoring campaign was carried out to evaluate the trend of some environmental parameters that are considered to be significant when varying the external airflow rates handled by the HVAC system. Additionally, dynamic simulations were carried out, with the aim of evaluating the energy savings coming from the airflow rates reduction. The results of this case study highlight the opportunity to achieve significant energy savings, with only slight variations in IEQ; a 50% reduction in airflow rate would decrease energy consumption by up to 45.2%, while increasing the carbon dioxide concentration from 545 ppm to 655 ppm, while the Particulate Matter and Total Volatile Organic Compounds increase is insignificant.

Distributed Energy Resources Management 2018

The Special Issue “Distributed Energy Resources Management 2018” includes 13 papers [...]