Residential Scale Research Articles

Street-level built environment on SARS-CoV-2 transmission: A study of Hong Kong

Understanding the association between SARS-CoV-2 Spatial Transmission Risk (SSTR) and Built Environments (BE) is crucial for implementing effective pandemic prevention measures. Massive efforts have been made to examine the macro-built environment at the regional level, which has neglected the living service areas at the residential scale. Therefore, this study aims to explore the association between Street-level Built Environments (SLBE) and SSTR in Hong Kong from the 1st to the early 5th waves of the pandemic to address this gap. A total of 3693 visited/resided buildings were collected and clustered by spatial autocorrelation, and then Google Street View (GSV) was employed to obtain SLBE features around the buildings. Eventually, the interpretable machine learning framework based on the random forest algorithm (RFA)-based SHapley Additive exPlanations (SHAP) model was proposed to reveal the hidden non-linear association between SSTR and SLBE.The results indicated that in the high-risk cluster area, street sidewalks, street sanitation facilities, and artificial structures were the primary risk factors positively associated with SSTR, in low-risk cluster areas with a significant positive association with traffic control facilities. Our study elucidates the role of SLBE in COVID-19 transmission, facilitates strategic resource allocation, and guides the optimization of outdoor behavior during pandemics for urban policymakers.

Modeling a poiseuille flow through a rectangular pipe in a floor slab (PSD)

This study was devoted to the modeling of a laminar fluid flow in a pipe of the rectangular section located in a floor slab. This theme was raised because of its relevance in the large business sector as well as in the areas of energy saving and storage at the residential scale. The equations of motion quantity and heat transport are the classical equations of forced convection. However, to describe the movement amount within the heating slab pipeline, Prandtl simplified model was most appropriate. In addition, this model retains the most important terms for a laminar regime flow. In addition, the modeling of fluid flow conservation in the pipeline was taken into account in the equation system. To achieve the above-mentioned objective, a numerical resolution was made for the system resolution of the Navier-Stokes equations that govern this fluid flow. These equations were discretized by an implicit finite difference method. The system of algebraic equations as well as obtained was solved by the algorithm of Gauss and the algorithm of Thomas. The results obtained such as: the evolution of the fluid velocity profile within the slab according to pipeline to the Reynolds number variation, the fluid temperature have clearly demonstrated the Poiseuille effect on fluid flow. Moreover, the stabilization of the Gauss algorithm and the Thomas algorithm in this numerical modeling was well verified against the tricks that were taken into consideration. The result of this study was that Thomas algorithm and Gauss algorithm are the best in this type of numerical modeling.

Impact of the net-metering policies on solar photovoltaic investments for residential scale: A case study in Brazil

The adoption of renewable energy resources is in the core of energy transition. However, its implementation can be highly impacted by country policies. A limited number of researches investigated solar photovoltaic investments, comparing net-metering rules for distinctive energy consumption levels and different discounted rates, from the investors’ point of view. This paper analyzes the impact of Brazilian net-metering rules on solar photovoltaic investments, considering residential scale. The methodology contemplates the development of a Discounted Cash Flow model to calculate Discounted Payback (DP), Net Present Value (NPV), Internal Rate of Return (IRR), and Levelized Cost of Electricity (LCOE) of projects. The case studies consider the impact of Brazilian regulation from net-metering rules (previous, considered, and current), energy consumption levels (Low, Middle, and High), and discount rates (5 %, 10 %, 15 %, and 20 %). The results show that from the previous to current rule the return for investor, on average, decreased 5.77 %. However, this reduction would be of 12.81 % if considered rule was adopted. For the 36 studies carried out, even in the worst case the investments remain viable. Therefore, the existing policy is suitable for the current stage of sector development; minimizing the impacts for energy tariff, distribution companies, consumers, and prosumers.

Behind the Privative Space Obstruction. Investigating Visual Perception Privacy, Downtown Algiers’ Mass Housing

The present paper brings forth visual perception privacy issue in mass housing in Algiers. Considering a correlation between obstruction rates and visual perception privacy, the case study was selected to measure dwellers’ satisfaction according to Altman’s theoretical framework. A qualitative method was adopted and a semi-guided interview was conducted with 28 downtown mass housing residents in Algiers. On the other hand, to understand outsiders’ perspective regarding downtown dwellings’ perception, the qualitative method was supplemented by a survey involving 94 participants. Both methodological tools were structured according to previous non-participatory observation. Finally, the investigated area appears as being double-scaled: on an urban scale visual perception privacy measurement, people are satisfied, while on the residential scale, dissatisfaction prevails. From outsiders’ perspective, dynamic motions combined to street furniture create a visual protective shield between dwellers and unfamiliar outsiders, as the later perceive environment on a cognitive dimension, while familiar outsiders perceive it on an affective-emotional symbolic dimension.

Formulation of billing policy for residential scale solar PV systems and its impact in the Kingdom of Saudi Arabia

Governments worldwide have introduced diverse billing methods and regulations to promote the adoption of photovoltaic (PV) systems, aiming to reduce greenhouse gas emissions. This paper aims to develop a billing policy for installing rooftop PV systems in the Kingdom of Saudi Arabia by studying policies implemented to support installing PV systems in leading countries. Initially, the system is evaluated using the tariff predetermined by Saudi Electricity Cogeneration Regulation Authority under three different policies: a Feed-in Tariff (FIT), net metering, and net billing for different sizes of solar systems 10 kW, 15 kW, and 20 kW. The findings suggest a considerable discounted payback period ranging from 14 to 20 years under the net metering framework with the current tariff structure. In contrast, investments under FIT and net billing schemes do not appear to be viable. Thus, a tariff schedule, tailored according to the consumer-preferred payback period, is proposed. For a payback timeframe of 6–10 years, the tariff should range between $0.09–0.06 $/kWh within the FIT scheme. However, in the case of a net billing policy, the tariff should vary between $0.123–0.066 $/kWh. These findings suggest the supremacy of the FIT scheme, particularly if the government determined to use the low tariff policy.

Experimental validation of a low‐voltage regulator model—A case study of a Maltese low‐voltage feeder

AbstractSolar photovoltaics in Malta have increased substantially over the years, both at large scale and residential scale. The present installed capacity is already having a negative impact on Malta's’ grid infrastructure, causing problems due to the reverse power flows (resulting from oversupply) and related issues such as voltage rise. This paper considers the integration of a low voltage regulator in a low voltage feeder in a semi‐rural area in Malta. A thyristor‐controlled transformer‐based low voltage regulator was modelled and simulated in MATLAB/Simulink using the PLECS blockset. Experimental results were also obtained via measurements of the voltage profiles at 70% of the actual low voltage feeder that showed several instances of over and under voltage events. The outputs obtained from the simulation model strongly agreed with those obtained from the field testing thereby validating the simulation models that were developed in this study. Results show that the voltage on the feeder was successfully regulated to around the nominal voltage of 240 V. The regulator failed to correct the voltage to within ±10% in one occurrence where the load demand and hence the voltage drop was too high.

Access to Electricity Through Diesel and Photovoltaic Mini-grids at the Residential Scale in Developing Countries: Spatial Distribution and Socio-Economic Factors

Access to Electricity Through Diesel and Photovoltaic Mini-grids at the Residential Scale in Developing Countries: Spatial Distribution and Socio-Economic Factors

Personalized PV system recommendation for enhanced solar energy harvesting using deep learning and collaborative filtering

Electricity is a crucial aspect of modern life, and with the increasing population and industrialization, energy demand has risen significantly. A swift transition to renewable energy sources such as wind and solar is essential for saving the planet. Solar energy is one of the most widely used renewable energy solutions, but choosing a PVSC poses a challenging problem that involves considering various factors, such as geographical location and energy consumption patterns. In this study, we investigate the effectiveness of using machine learning techniques to assist users in selecting the most suitable PVSC for their needs. We propose a new framework for PVSC recommendation, which encompasses a PV power forecasting model and a PV configuration recommendation system.We propose two forecasting models, one based on LSTM and the other based on CNN architecture. These two elements are responsible for extracting relevant features from time-series meteorological data, which are then passed to a feed-forward MLP layer that predicts the monthly energy production for different PVSCs. Subsequently, the prediction results are utilized to determine the optimal Residential scale PVSC for households, taking into account location and historical consumption data. The system was trained on simulated data and then tested on both a hold-out simulated test set and a real-world dataset. Our experiments show that the proposed framework is effective for long-term PV power forecasting and PVSC recommendation.

Optimizing geometrical structure of a residential parabolic solar collector relying on hydrothermal assessment and second law analysis

Researchers are interested in the optimization of thermal systems due to the rising demand towards renewable and green energy to reduce greenhouse gasses and expenses. To achieve this, the present work aims to conduct the numerical modeling on the residential scale trough solar collector. For this purpose, the lattice Boltzmann method is employed with special treatment for the curved physical boundaries. To enhance the thermal capability of the solar collector, the CuO-water nanofluid is utilized, which its thermal conductivity is estimated using Koo–Kleinstreuer and Li (KKL) model. Furthermore, the Brownian motion effect on the dynamic viscosity is taken into account. In addition, the local and volumetric second law analysis is performed. Besides, the heat line visualization is done to capture the path-line of heat energy within the solar collector. The thermal distribution, flow field, local entropy production (i.e. fluid friction irreversibility and heat transfer irreversibility maps), volumetric entropy generation, Bejan number, and average Nusselt number are the studied items in terms of the governing parameters. The Rayleigh number (103 ≤ Ra ≤ 106), CuO nanoparticle concentration (φ = 0, 0.01, 0.02, 0.03, 0.04) and four structural design of the solar collector (Single-pipe, Double-pipe, Triple-pipe, Quadruple-pipe) are assumed as the governing parameters.

Investigating the Cost-Effectiveness of Solar Electricity Compared to Grid Electricity in the Capitals of Middle Eastern Countries: A Residential Scale Case Study

Despite of being rich in fossil fuels, the Middle East is currently the main energy consumer and is projected to have the highest growth in energy demand in the world. Due to its great potential in the Middle East, solar energy can play an important role in the plans of energy decision-makers in the region. According to the studies done so far, no study has been done to show the potential benefit of using home-scale solar systems in the Middle East. Therefore, in this work for the first time, the potential of solar electricity production in the capitals of Middle Eastern countries has been studied using HOMER V2.81 software. The investigations are technical, economic, energy, and environmental, and the studied solar system is connected to the national electricity grid. The results showed that in Nicosia, due to the sale of electricity to the grid, the levelized cost of electricity (LCOE) is equal to -0.759 $, which is the lowest price for produced electricity and leads to a return on investment time of 5.69 years for this system. The solar fraction for the Nicosia station is 92%, which prevents the emission of more than 8 tons of CO2 pollutants during the year. The highest value of LCOE with the amount of $0.25 is related to Sana’a, whose investment return time, solar fraction, and annual CO2 emission prevention amount are 14.1 years, 53%, and 1162 kg, respectively. Ranking analysis was done on the results of 5 outputs of the HOMER software as well as 3 other influential parameters using 4 multicriteria decision-making (MCDM) methods. TOPSIS, GRA, WSM, and AHP methods were used, and the final ranking of each station was considered the average of the 4 methods. According to the results, Cyprus and Kuwait stations were the best and worst, respectively.

Development of an acoustic flowmeter for low flow rates

The use of non-intrusive acoustic flow meters for residential applications has been little explored. This work presents the development of a non-intrusive acoustic instrument for low water flow rates measured at a PVC pipe knee. A chest piece of stethoscope with an electret microphone was used, and 10 collection cycles were performed, in a range of 16–488 L/h (lph). The results show that there is a quadratic relationship between the standard deviation of the acoustic signal and the water flow, and the existence of a transition region is predicted. Furthermore, there was an exponential relationship between the standard deviation of the detail coefficients of the Wavelet Transform and the energy of the approximation coefficients with the fluidic flow. Thus, as far as we know, this is the first time that a correlation between the acoustic noise generated by a low flow of water on a residential scale is presented. This approach represents a potential alternative for monitoring water consumption at specific points in a residence, which, in turn, enables the identification of user patterns and contributes to the management of the distribution of water resources in a given location.

Readiness of Malaysian on Sustainable Development in Solar Energy Application

Solar energy is a non-vanishing renewable source of energy that is eco-friendly. However, the solar energy adoption rate in Malaysia remains low due to the low readiness level among the Malaysian. This phenomenon should be emphasized where solutions need to be figured out to encourage the adoption of solar energy in buildings. Thus, this research was conducted to explore the readiness and challenges of the Malaysians in adopting solar energy. A mixed research method was adopted where a totalof 200 sets of online questionnaire surveys were distributed to the public, and a semi-structured interview was carried out to obtain the opinions from the expert in the industry. Based on the findings of the questionnaires, the top 3 challenges in solar energy adoption are (1) high setting up cost of solar panels, (2) limited public awareness of solar energy and (3) efficiency of the solar panel depends on the weather. Next, the qualitative study found that 48.9% of 139 respondents were willing to adopt solar energy in the future. The findings show that that breaking down the barriers of high investment cost and long return investment would further enhance the solar energy adoption rates at the residential scale. Since this study had explored the challenges and solution to these barriers, the outcomes of this study can be used by the policy maker as the fundamental to encourage the adoption of solar energy in the existing buildings where the current adoption rate is low.

Design of Pico-Hydro Power Plant with Monitoring System Based on Internet of Things

Currently the electrification ratio in Banyumas Regency is around 79%. This means, of the 1.7 million residents of Banyumas Regency, only around 21% have not enjoyed PLN electricity. Those whose homes have not yet had electricity are on average residents who are on the slopes of the mountain slopes, and some residents in several groves in remote areas in Banyumas Regency which are very far from the PLN electricity network. This problem can be overcome by providing electrical energy by utilizing renewable alternative energy, one of which is micro hydro or pico hydro power plants on an individual or residential scale. Therefore, this research designed a simulation of a pico hydro power plant using a Pelton turbine which is expected to be able to provide benefits to the general public, this tool is equipped with remote monitoring using Google Firebase based on the Internet of Things which can be monitored via the Android application for monitoring Voltage, current and power use the INA219 sensor which has been programmed on Arduino Uno and Node MCU ESP8266. This tool uses a 12-24 Volt DC generator, produces DC electricity which is stored in a 12 Volt 5 Ah battery which is then converted using an inverter to become AC electricity. In this test using a 5 Watt AC lamp load, the battery voltage which was initially 12.6 Volts was reduced to 9.9 Volts, the lamp load was able to light up for 1 hour. In measuring the voltage and current, the generator produces an average voltage of 15.9 Volts and a current of 50.2 mA.

Residents’ territorial cognition and behavior patterns: An inquiry into Kavaklıdere and Çukurambar Districts of Ankara, Turkey

As a part of the recent urban restructuring processes, the spatial layout of residential environments as street-based neighborhoods has left its place to cellular developments in the form of gated communities. This shift in the spatial organization altered the relationship of urbanites with their near-home environments. This research aims to depict the influence of this shift on the cognitive and behavioral patterns of the residents. To do so, it re-interprets the concept of ‘territoriality’ as a critical tool for understanding and regulating the dynamics of human-environment relations at this scale. A model to assess territorial functioning is developed and employed in the Kavaklıdere and Çukurambar Districts of Ankara, the capital of Turkey. Comparative field surveys are conducted in the districts by using interpretative methods, including direct systematic observations and questionnaires with the residents. The districts are selected as prominent examples representing the aforementioned shift. The research findings reveal that, along with other exogenous factors, spatial layouts are the primary factor that promotes and inhibits certain cognitive and behavioral patterns at the residential scale. Both the findings from the case studies and the methodological proposition of the study contribute to the ongoing discussions in the field of urban planning regarding the future design of residential environments, which has regained attention with the multi-functionality of home environments during the COVID 19 pandemic. The study highlights the importance of the spatial design of residential environments on access to resources, the sense of security, identity, and well-being of the residents from the perspective of human-environment relations.

Experimental Study on the Thermal Behavior of Building Materials in A Dry and Arid Climate

This paper analysesthe performance ofmaterialconstructions intwosmallcubicle roomsduring hot and cold periods, based on the results of experiments conducted at the University of Ouargla in southeasternAlgeria. The climatic conditions in this region are extreme. The outdoor ambient temperature varies between 47 C° during the day and 30 C° at night for the hot period, and between 16 C° during the day and -1 C° at night for the cold period. The rooms of the in-situ cubicles were identical with a dimension of 1 m × 1 m × 1 m. The walls of the stone cubicles were made with Ouargla stone (15 cm) and two layers of gypsum (1.5 cm), and for brick, the walls of the cubicles were made with hollow brick (15 cm) andtwo layers of mortar (1.5 cm). Measurements are made of ambient temperatures, wall temperatures, and instantaneous heat flux densities through the walls. The effect of building material selection on energy consumption was also studied. During two differentperiods (August 28-30, 2020) and (October 21-23, 2020), the construction with stone decreased the indoor temperature by approximately 6 °C during the day and reduced the apparent thermal mass of the room in the first period, but in the second period, theindoor temperature increased by approximately 1 °C. The residential scale confirmed that Ouargla stone improves thermal comfort by providing high insulation and reducing indoor temperature oscillations. This material is abundant in nature and can be easily extracted and used directly in constructing houses without recycling it, which helps reduce CO2 emissions.

Modeling and Analysis of a Thermophotovoltaic Integrated Self-Powered Furnace

This work investigates the energy efficiency and carbon reduction potential of self-powered residential building heating equipment using a thermodynamic modeling approach. An integrated thermophotovoltaic power module and residential scale furnace system (40,000 Btu/h) were modeled and studied in detail to assess the influence of different design configurations on primary energy efficiency. Operational characteristics such as total power generation, electrical efficiency, and heat recovery were examined in a self-powered system configuration. A sensitivity analysis was conducted to determine the influence of the electric grid’s carbon dioxide footprint (carbon intensity) and the cost of electricity on the environmental, as well as the economic, benefit associated with the self-powered configuration. Compared with a traditional furnace powered by an electric grid at a carbon intensity of 0.5 kg CO2eq/kWhEL, the self-powered furnace was shown to decrease the annual carbon dioxide emissions by approximately 550 kg (~75% reduction), while also saving more than USD 200 in utility expenses, annually. Additionally, the carbon emission reduction potential of blending different concentrations of hydrogen in natural gas fuel was also studied.

Moisture‐dependent engineering properties of underutilized browntop millet (unhulled and hulled) and characterization of milled flour

Browntop millet is an underutilized indigenous cereal crop. It is termed as the nutricereal due to its superiority in terms of nutritional quality. The current study attempted to investigate the effect of moisture content (10%–27%) on properties such as physical, mechanical, aerodynamic, and textural properties of unhulled and hulled browntop millet to uncover the gaps in developing the efficient primary processing machinery. In addition, we investigated the impact of milling on the biochemical, functional, color, structural, and powder flow properties of browntop millet flour. The results revealed that as the moisture content increased, the principle dimensions, 1000 grain weight, terminal velocity, angle of repose, and static coefficient of friction were linearly increased. In the same moisture content range, characteristics such as true density, bulk density, porosity, and hardness displayed an inverse trend. Milling showed a substantial (p < 0.05) influence on the nutritional, functional and color parameters. FTIR spectra and X-ray diffraction patterns demonstrated a slight change in functional groups and a slight decrease in starch crystallinity respectively. All three millet flours were cohesive. These flours, however, exhibited a positive correlation with bulk density and a negative correlation with wall friction and effective internal friction angles as the principle consolidating stress increased. Practical Application Millets are a globally significant food crop with major economic influence in developing nations. They are one of the most significant drought-resistant crops, and a good source of health-promoting complex carbohydrates, dietary fiber, phenolic compounds, and phytochemicals. Despite of their high nutritional superiority and environmental friendliness, production and consumption have declined over the years. The significant factor contributing to this decline is the lack of machinery or equipment available to process on a commercial and residential scale after harvest. The knowledge of the measured properties will encourage researchers to develop and modernize equipment used for destoning, grading, sorting, separation, dehulling, and conveying. The measured nutritional, mineral, functional, structural, and powder flow properties of milled browntop millet fractions will help develop a new product. So that millet can be used to its full potential.

Building Information Modelling (BIM) and the impact on landscape: A systematic review of evolvements, shortfalls and future opportunities

The last decade has notably witnessed a major impact on our climatic characteristics and way of living across urban and rural areas. Following the intensified effects of the climate crisis as well as the crisis of the COVID19 pandemic, this paper aims to cross silos and explore how the sectors of landscape, digital transformation and the built environment can support a resilient future. In the built environment, the impact of digital tools such as Building Information Modelling (BIM) can be recognised across many processes to deliver better value, improve productivity and drive innovative solutions. It can however be noted that most efforts have looked into the impact of BIM at a micro scale (e.g. buildings and developments) with limited focus at the macro scale (e.g. landscape design and climate change). This paper focuses on the digital technology innovations through the lens of the landscape and the exploration of how such tools could contribute to the form of planning and landscape design. It aims to lay a critical review of the impact of BIM on the landscape with insightfully pointing out evolvements, shortfalls and future opportunities. The paper adopts a hybrid approach that includes a systematic selection of research papers focusing on landscape with particular emphasis on climate change, planning and urban design between 2010 and 2021. Findings suggest that, with relation to BIM's impact on the landscape, most efforts have focused on planning and the small residential scale. Findings also showed that there are limited efforts to investigate landscape design and urbanism and the ways in which digitalization can support sustainable development in open spaces. The area of climate change is significantly overlooked within BIM, raising concerns on the lack of current research on such a critical topic. Using the knowledge from BIM technology, the study provided evidence on the correlation with the landscape and climate change. Evidence demonstrates there is limited connection between BIM and landscape and therefore the study discusses how such tools can improve the understanding of the landscape idea as well as support the creation and visualization of environmentally friendly landscape designs. Future work includes looking into many of the highlighted trends as a result of the study with further investigation on the role that stakeholders can play as part of the digital transformation on landscape.

Microplastics in the continuous biofilm reactor: Occurrence, fate, and removal

The occurrence of microplastics in a continuous biofilm reactor during the process over a period of 53 days poses a concern for the quality of the treated water. The aim of this study seeks to expand the knowledge of the dynamic of microplastics inside biofilm reactors by investigating their occurrence, fate, and removal. A 91.5 L continuous laboratory-scale reactor consists of four compartments, anoxic-1, anoxic-2, aerobic (A2O), and sedimentation. It was fed with raw domestic wastewater from a residential scale of the wastewater treatment plant in Bandung, Indonesia. In order to investigate the occurrence of microplastics inside a biofilm reactor, it is crucial to consider into account all treatment stages. The results showed that the abundance of microplastics in the influent and the final effluent were 810 MP/L and 10 MP/L respectively. The A2O process in this study demonstrated a high potential for microplastics removal from residential wastewater, in which it could be removed 99.18% of microplastics. The highest abundance was retained in the sludge. The remaining was found in the biofilm and in the final effluent. Microplastics less than 500 μm in size with the abundant microplastics types of fiber, and fragments were detected most frequently in the samples. Moreover, polyester (PES) and cotton were the dominant polymer types in the biofilm reactor detected by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR).

A Panel Data Approach towards the Effectiveness of Energy Policies in Fostering the Implementation of Solar Photovoltaic Technology: Empirical Evidence for Asia-Pacific

Today, the growing Asia-Pacific population causes a dramatic growth in energy supply to meet energy demand. The rapid rise in energy demand is causing concern in the region. Thus, the present study scrutinizes the effect of energy policy involvement in steering-up renewable energy development by empirically assessing the role of policy instruments in encouraging residential-scale and commercial-scale photovoltaic (PV) systems. The analysis is performed using a fixed effects estimator on a selected range of policy approaches (market-pull policies and tax incentives) and a technology-push policy (capital grants) in selected Asia-Pacific countries between 1998 and 2015. The return on investment is estimated to measure the incentives of feed-in tariff (FIT) tariff policies for both residential-scale and commercial-scale PV systems. This study has shown the importance of a strategic combination between technology-push and market-pull policies as complementary to adopting technology and increasing renewable energy utilization for solar PV systems on a residential scale. Investigations into the effectiveness of regulatory support policies for solar PV systems indicate that energy policies are necessary to facilitate solar PV growth on a residential scale in the Asia-Pacific.